1IMDEA Materials Institute, Spain
2Universidad Rey Juan Carlos, Spain
Development of safer and environmental friendly high energy density rechargeable batteries capable of fast charging and long-term cycling stability is one of the key challenges for modern electrochemistry. During the last two decades, Li-ion battery technology attracted extensive attention due to their widespread application in portable electronics, medical implants, grid-level energy storage and electric vehicles. Recently, secondary Na-ion batteries emerged as a promising candidate for large scale energy storage. This technology attracted immense interest due to low-cost and abundance of resources compared to limited lithium supply. Despite of the several advantages of Li and Na-ion batteries, their energy and power densities are not sufficient for more energy demanding commercial applications such as long-range driving. Pseudocapacitive charge storage is lately demonstrated as a method to improve the power-density of transition metal carbides (MXenes). However this method is difficult to achieve in case of transition metal oxide electrodes due to their low ionic and electronic conductivity. Tailored designing of these electrode materials are therefore required to induce pseudocapacitive Li and Na ion storage.
We have demonstrated pseudocapacitive assisted Li and Na ion storage in ultrathin Co3O4 nanosheets, hierarchical Co3O4 nanorods, biphasic TiO2 nanosheets and CoO-RGO hybrid electrodes. In the case of Co3O4 based anodes, a maximum Li and Na ion storage capacity of 1400 and 700 mAh/g respectively was obtained (300 mAh/g for biphasic TiO2 nanosheets). Excellent specific capacity (higher than theoretical limit), rate performance and cycling stability are attributed to pseudocapacitive contribution resulting from tailored interfaces, defects and crystal facets.
Biography:
Dr. Vinodkumar Etacheri is a scientist and electrochemistry group leader at IMDEA Materials Institute, Spain. Dr. Etacheri obtained his PhD in Materials Chemistry from Dublin Institute of Technology (DIT), Ireland in 2011. He then completed postdoctoral research at Bar Ilan University- Israel, University of Michigan- USA and Purdue University USA in the area of Li-ion, Li-O2, Li-S, and Na-ion batteries. His research areas extend from solar energy conversion to electrochemical energy storage materials and devices. He co-authored more than 25 papers (> 3700 citations) in international peer reviewed journals, 3 book chapters, and 8 patents.
Yale University, USA
Solar-to-chemical conversion mimics natureʼs photosynthesis, for example, taking sunlight and splits water into H2 and O2. Once abundant and low-cost solar fuels of H2 is produced as a universal energy carrier, we can use it to convert synthetic fuels, upgrade bio-fuel feedstock, improve combustion and even produce ammonia. However, achieving such an efficient artificial leaf is not trivial, particularly due to the instability of efficient semiconductor/liquid interfaces: technologically important semiconductors like Si and GaAs photocorrode in water. Because of this, protective coatings are emerging as an essential design component in the field of photoelectrochemistry (PEC) and photovoltaic energy conversion. Achieving an efficient photocatalytic device is not trivial, particularly due to the instability of efficient semiconductor/liquid interfaces. Particularly, instability of solid/liquid interfaces during water oxidation in acid is the remaining challenge. In this work, we present the synthesis of thick (Ti, Mn)Ox ternary mixed oxide films (> 20 nm) by using atomic layer deposition (ALD) to extrinsically modify the original, “leaky” TiO2 coatings and preserve their robust chemical, electrochemical and mechanical stability in acid. We discovered a p-type oxide of (Ti, Mn)Ox can transport holes via defect bands to high work function co-catalysts such as Ir, Pt and Au metals, Ru oxides and Ir-based molecular water-oxidation catalysts. Unprecedented stability has been observed for >100 hour water oxidation in pH = 0-1 sulfuric acid at 1–2 mA.cm-2, with no detectable surface degradation. We will show electrical, electrochemical and spectroscopic analysis of this p-type oxide in a wide composition range. Such an p-type, acid-stable surface layer promises many critical applications in oxidative photochemistry and earth-abundant photovoltaics.
Biography:
Shu Hu is an Assistant Professor of Chemical & Environmental Engineering at Yale University. He is also affiliated with the Energy Science Institute at Yale West Campus. Shu Hu graduated from Tsinghua University in 2006 and received his PhD degree of Materials Science and Engineering in 2011 from Stanford University, where he worked on nanoscale germanium-silicon crystal growth and epitaxy control. He was then a postdoctoral scholar at California Institute of Technology and Joint Center for Artificial Photosynthesis. His work spans fundamental and applied research areas in nanophotonics, nanoscale group III-V growth and solid-electrolyte interfaces for artificial photosynthesis. The experimental demonstration of protective coatings was highlighted in major media including NPR News, Scientific American, CE&N News, and Nature.
Department of Energy Conversion and Storage (DTU Energy), Technical University of Denmark, Denmark
Energy conversion and storage technologies relies in most aspects on proper design and application of various nanotechnologies. In this presentation, examples of the importance of nanotechnologies in areas of fuels cells, electrolysis, batteries and thermoelectric generators, will be presented and discussed.
The nanotechnologies in play are e.g. nanostructured electrodes manufactured by impregnation, buffer layers manufactured e.g. by pulsed laser deposition (PLD), electrolytes by e.g. PLD and sputtering, protective coatings and current collecting layers manufactured by e.g. electroplating, and nanostructured maintained during sintering by plasma sintering.
Biography:
Soren Linderoth is Professor in Functional ceramics for energy purposes. Head of Department (DTU Energy). Co-author of more than 200 scientific papers, and 30 patents.
1School of Energy Science and Engineering, Harbin Institute of Technology, China
2Center for Composite Materials and Structures, School of Astronautics, Harbin Institute of Technology, China
Solar steam generation, as a traditional way to utilize solar energy with photo-thermal conversion, has great potential applications, including wastewater treatment, desalination, chemical concentration and recovery. For traditional solar steam generation with a black coating in the bottom of the solar pond, the steam generation efficiency was relatively low due to the weak light capture capacity and large thermal loss. Therefore, many nano materials have been used to improve the steam generation process, such as noble metal, semiconductor, carbon and other composite materials. Except for the application of some nano materials to enhance solar absorbance, different evaporation processes were designed to reduce the heat loss to the bulk water and the environment. For example, volumetric evaporation using nanofluid could enhance photo-thermal conversion and improve solar steam generation efficiency. Membrane evaporation using micro-nano structure membrane could further reduce the thermal loss with heat concentration effect due to the localized surface plasmon resonance. In brief, the key to improving solar steam generation is to enhance light capture and heat concentration.
In this work, several different membranes with Au, TiO2 nanoparticles and different substrates were prepared and their photo-thermal conversion capacities were investigated. Through the solar water evaporation, the enhancement to solar steam generation rate and efficiency were also studied. It was found that compared with volumetric evaporation, a hot area could be formed using the membrane structure, which is conducive to the heat concentration. Besides, the heat loss could be reduced through reducing the contact area between the membrane and water.
Acknowledgement: This work is financially supported by the National Natural Science Foundation of China (Grant No. 51421063, No. 51676060), the Natural Science Founds of Heilongjiang Province for Distinguished Young Scholars (Grant No. JC2016009).
Biography:
Mr. Jian Huang obtained his B.S. Degree at Harbin Institute of Technology in China in 2016, and is a postgraduate student of Harbin Institute of Technology at present. Until now, he has published 2 patent applications and 4 papers. His current research focuses on solar energy utilization, heat and mass transfer, and solar seawater distillation.
1Department of Chemistry, University of Kalyani, India
2National Centre for Ultrafast Processes, University of Madras, India
3Department of Inorganic and Physical Chemistry, Indian Institute of Science, India
Over the past few years, sensitization of large band gap semiconductors by organic dyes has received considerable attention in research due to the potential applications of such Dye/Semiconductor (D/SC) systems. One of the important applications of such D/SC systems is in the photoanodes of Dye Sensitized Solar Cells (DSSCs), the semiconductor of choice in such systems being TiO2[1]. Effective electron transfer from the excited dye to the TiO2 conduction band requires good electronic coupling between the two. Hence the scientific focus is on dye sensitization of TiO2. Among various categories of dyes used as photosensitizers, Porphyrins are promising because of their strong Soret absorption and moderate Q-band absorption. The present talk will focus on the work done at our laboratory on the synthesis of interesting TiO2 based nanomaterials i.e. nanoparticles and nanosheets and their subsequent sensitization by porphyrins. The emission intensity of the porphyrin dyes is quenched by the TiO2 based nanomaterials and the dominant process for this quenching has been attributed to photoinduced electron injection from the excited state of porphyrin to the nanomaterials. We have shown how the Porphyrin/TiO2 systems show extremely fast rates of electron injection (1011 s-1 for the porphyrin/nanosheet system) while the rate of back recombination is much retarded (103 s-1 for the porphyrin/nanoparticle system). Both these effects will be beneficial for efficient functioning of future solar cells based on such photoanode materials.
References
[1] B. OʼRegan, M. Gratzel, Nature 353 (1991) 737-740.
Biography:
Swati De did her PhD in 1998 under Professor Kankan Bhattacharyya, a reknowned spectroscopist. She joined the Department of Chemistry, University of Kalyani, India as an Assistant Professor in 1999. She has been there since and is presently Professor. She did her post doctoral work with Professor Villy Sundstrom at Lund University, Sweden.
She has published several research papers, one invited Book Chapter in the Encyclopedia of Biocolloid and Biointerface Science, John Wiley and Sons. She has an h-index of 19 (Scopus). She has completed guidance of 7 Ph.D students and several others are working. Her research interests are: Application driven synthesis of nanomaterials and Fluorescence probing of membrane mimicking systems.
1University Paris Est, IFSTTAR, France
2Laboratory of Physics of Interfaces and Thin Films, Ecole Polytechnique Palaiseau, France
3Laboratory of Catalysis and of Corrosion Materials (LCCM), Faculty of Sciences, University Chouaib Doukkali, Morocco
4ICube-Laboratory of Engineering, Computer Science and Imagery, University of Strasbourg, France
5Department of Energy Science, Sungkyunkwan University, South Korea
In this work, we present a practical approach for controlling Single Walled Carbon Nanotubes (SWCNTs) diameter distribution through thin film Ru catalyst coupled with hydrogen pre-treatment. Uniform and stable Ru nanoclusters were obtained after dewetting the Ru thin films under atomic hydrogen pre-treatment. SWCNTs were synthetized by double hot filament chemical vapor deposition (d-HFCVD) on SiO2/Si substrates at different temperatures. We found that the temperature is an important synthesis parameter that influences the diameter distribution of the final SWCNTs. Statistical analysis of the Raman radial breathing modes evidences the growth of highly enriched semi-conducting SWCNTs (about 90%) with narrow diameter distribution that correlates directly with the catalyst particle size distribution. Electrical measurement results on as-grown SWCNTs show good thin-film transistor characteristics.
Biography:
Dr. Fatima Bouanis, physico-chemist, received the masterʼs degree from “Ecole Nationale Superieure de Chimie de Lille” and the PhD from “University des Sciences et Technologies de Lille” in 2009. From 2009 to 2011, she worked jointly at LPICM (Laboratoire de Physique des Interfaces et des Couches Minces)-Ecole Polytechnique France and ICMMO (Institut the Chimie Moleculaire et des Materiaux dʼOrsay)-France as a post-doctoral fellow on carbon nanotube electronics and from 2011 to 2012, she worked as post-doctoral “sensors based carbon nanotubes” at LPICM and PSA. Since 2012, she is researcher at IFSTTAR-France within NACRE (LPICM-LISIS) joint research team and she is a member of Sense-City project team. Her research focuses on sp2 carbon-based selective sensing for urban environmental applications. She is involved in carbon nanotubes and graphene synthesis and collective organisation for advanced electronics and novel devices (CNT-based FETS, gas/biological sensors, Memristors, Inverters...). She supervised two PhD students, 1 post-doc and has supervised several master students. F. Bouanis authored or co-authored 11 peer-reviewed publications, and 2 patents. She is member of management committee of COST ACTION CA 15107 Multi Comp “Multi-Functional Nano-Carbon Composite Materials Network”.
Department of Materials Science & Engineering, National Tsing Hua University, Taiwan
Quantum dots (QDs) are currently considered to be a solution for future display standards and are being applied to LCD displays for colour improvement. Various application types of QDs in displays are under development, e.g., polymer/QDs thin films, QD light-emitting-diodes (LED), QD color filters and QD electroluminescence devices (QLED), in which the thin film type has been introduced to high-end display products by the main TV brands. Current challenges of the QD-based displays are colour impurity, emission efficiency and thermal stability that still need to be further improved. In this report, we will go through the various application types of QDs in lighting and displays. In particular, the polymer/QDs thin films and QD LEDs will be surveyed and discussed regarding of the narrow emission bands (full-width at half-maximum, fwhm < 30 nm) and thermal stability/reliability.
Biography:
Dr. Hsueh-Shih Chen received his PhD in 2009 from the University of Cambridge. Before his study in Cambridge, he worked as a researcher for 5 years at Industrial Technology Research Institute (ITRI) in Taiwan. From 2009 to 2010, he was a special research fellow in the National Institute of Advanced Industrial Science and Technology (AIST) of Japan. In 2012, he was offered a fellowship by the Natural Environment Research Council, and worked as a research fellow at the University of Birmingham in UK. He begins his academic career at National Tsing Hua University, Hsinchu in 2013, as an assistant professor, and then becomes an associate professor in 2015 at the Department of Materials Science and Engineering. He has published more than 80 academic papers and 40 patents and is also a founder of two quantum dot companies.
1National Institute of Materials Physics, Romania
2National Institute for Laser, Plasma and Radiation Physics, Romania
Hitherto, going towards the nanoscale to explore new properties of materials given by the reduced sizes became the point of interest of an increased number of researchers. The main goal is to improve the physical and chemical characteristics of the nanostructures by controlling the preparation methods. Among nanostructures, nanowires denote a special category due their high aspect ratio and high surface area which can influence their optical and electrical properties. In core-shell radial junctions the light absorption and charge separation directions are more efficient than in planar junctions being orthogonal (absorption along the nanowire length, while the separation of charges within the diameter). Furthermore, when a staggered gap heterojunction (type II) is created, efficient charge separation occurs due to the built in internal field formed at the interface between the two semiconductors.
In this work, for promoting efficient charge separation for solar energy harvesting applications, radial staggered gap heterojunctions have been obtained as ZnO-CuO core-shell nanowires. ZnO is a n-type semiconductor having a direct wide band-gap of about 3.3 eV and CuO is a p-type semiconductor with an indirect band gap around 1.2 eV-1.6 eV.
The core-shell nanowires are prepared by dry physical methods, thermal oxidation in air and magnetron sputtering. The properties of the core-shell nanowires based on ZnO and CuO were assessed from the structural (X-ray diffraction, transmission electron microscopy), optical (reflection and luminescence measurements), morphological (scanning electron microscopy), compositional (energy-dispersive X-ray spectroscopy, X-ray Photoelectron spectroscopy) and electrical (electrochemical impedance spectroscopy) point of view. Different shell thicknesses of the core-shell radial staggered gap heterojunctions exhibit particular photocatalytic properties which are explained based on a mechanism which takes into account the partial or total dissolution of ZnO.
Acknowledgement: This work has been funded by the Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI), Romania, Project code: PN-III-P2-2.1-PED-2016-1249.
Biography:
Dr. Camelia Florica received her bachelor degree in Medical Physics from the University of Bucharest, Romania in 2009 and followed a Master program in Advanced Materials at the University of Bucharest, Romania and Université catholique de Louvain, Belgium. She has completed her PhD in Solid State Physics in 2015 from University of Bucharest, Romania. At the moment she is a Senior Researcher Degree III at the National Institute of Materials Physics, having 26 scientific articles in ISI journals and 7 national patent requests. She is currently leading a national research project on the topic of core-shell nanowires, Nanowire Photodet.
Laboratory for Precision and Nano Processing Technologies, School of Mechanical and Manufacturing Engineering, University of New South Wales, Australia
Monocrystalline silicon carbide is a promising material for advanced components and devices, because it has very strong covalent bonding and presents excellent properties such as ultrahigh hardness (25~30 GPa), very low coefficient of thermal expansion (~4 × 10-6/K) and outstanding thermal and chemical stabilities. However, these superior properties have also made SiC a difficult-to-machine material. This presentation will discuss our recent investigations into the deformation mechanisms of a SiC under nanocutting with the aid of large-scale molecular dynamics analysis. We studied six typical combinations of cutting plane and direction were studied, namely, (0001) < 1120 >, (0001) < 1100 >, (1120) <1100 >, (1120) < 0001 >, (1100) < 0001 > and (1100) <1120 >. We found that the cutting-induced deformation morphology, activated dislocations and cutting forces varied significantly under different combinations of cutting conditions due to the strong anisotropy effect of the material. By evaluating the actual depth of cut, elastic recovery, surface roughness and maximum subsurface damage depth, we identified that the basal plane (0001) along < 1100 > direction is the most suitable combination for nanocutting.
1Department of Chemistry, University of Limpopo, South Africa
2Sensor Lab, Department of Chemistry, University of the Western Cape, South Africa
The development of highly efficient electrocatalysts for hydrogen evolution reaction is a fundamental undertaking of the hydrogen economy. Herein, we investigated the electrocatalytic performance of conducting polymer (polyaniline, poly (3-aminobenzoic acid)/metal organic framework (HKUST-1) nanocomposites for hydrogen evolution reactions. The results show that the synthesized nanocomposites exhibit the best electrocatalytic efficiency at lower overpotential and the Tafel analysis ( transfer coefficient (α) and Tafel slope (b)) suggests that the rate-determining step is the Volmer (electrochemical discharge) coupled with either Tafel (chemical desorption) or Heyrovsky (electrochemical desorption) reactions.
Keywords: Electrocatalyst, Hydrogen Evolution Reaction, Conducting Polymer, Metal Organic Framework, Tafel Analysis
University of Hasselt, Belgium
Nanotechnology and nanomaterials are enablers of innovative devices and systems in the domain of ICT, wireless communication, medical devices. However it is largely ignored that also in the domain of Energy these developments will have major impacts. It is clear that in the domain of Smart Grids and Smart Cities, sensors and the wireless communication amongst these sensors will play a crucial role, but the focus of the presentation will be on how electricity generation, electrical energy storage and power electronics will be influenced by the developments in the nano-domain.
It becomes more and more obvious that, in order to fight climate change, distributed electricity generation by renewable energy sources will be key to reduce CO2-emissions. Amongst the renewable energy sources wind and solar energy have by far the largest technical potential in combination with cost-effectiveness to ensure economical viability. The presentation will focus on the approaches to insert nanomaterials and technologies in advanced (e.g. crystalline Si) and novel photovoltaic devices (e.g. perovskitebased thin-film solar cells) in order to increase their performance and achieve a further cost reduction. However intermittent sources like wind and sun have to be deployed hand-in-hand with new and cost-effective energy storage solutions as to ensure continuous equilibrium between electricity generation and consumption. Electrochemical storage in batteries near to the location where the energy is generated and consumed are certainly part of the solution. In this domain the developments on nanomaterials will improve the energy and power density of batteries by enabling nanosized particles with mixed ionic and electronic conductivity for the electrodes whereas the amount of passive material is reduced by the use of thin solid-state electrolyte layers. Last, but not least, in the electricity grid of the future electrical energy flows will be bidirectional (to and from the prosumer). This will require efficient convertors. This is enabled by novel devices based on high-bandgap materials like SiC and GaN and device structures in which nanosized features will be essential to obtain proper device operation.
Biography:
Dr. Jozef Poortmans received his degree in electronic engineering from the Katholieke Universiteit of Leuven, Belgium, in 1985. He joined the newly build Interuniversitary Micro-electronic Centre (IMEC) in Leuven where he worked on laser recrystallization of polysilicon and a-Si for SOI-applications and thin-film transistors. In 1988 he started his Ph.D. study on strained SiGe-layers. Both the deposition and the use of these SiGe-alloys within the base of a heterojunction bipolar transistor were investigated in the frame of this study. He received his Ph.D. degree in June 1993.
Afterwards he joined the photovoltaics group, where he became responsible for the group Advanced Solar Cells. He was involved in the start of imecactivities on thin-film crystalline Si solar cells, organic solar cells and III-V solar cells and became Department Director of the PV-department in 2003. In 2008 he started up the Si-PV Industrial Affiliation Program and collected the investment funds to build up the advanced Si-PV R&D-line of imec (S-line). As Program Director PV he built the industrial partnership active in the S-line. Presently, he is Scientific Director of the PV and Energy activities of imec since 2013. In the same year he was also appointed imec Fellow.
He has been a Board Member of Eurec Agency and is presently member of the Steering Committee of the EU PV Technology Platform. He also acted as General Chairman of the 21st European Photovoltaic Solar Energy Conference & Exhibition and of the SiliconPV 2012 Conference and has been active in the Scientific Committees of the leading PV-conferences.
Prof. J. Poortmans has authored or co-authored more than 500 papers that have been published in Conference Proceedings and technical journals. Since 2008 he is part-time Professor at the K.U.Leuven, where he teaches courses on photovoltaics and materials in electrical engineering. In 2013 he became also part-time Professor at University Hasselt where he teaches a course on analog electronics. In the same year he was appointed imec Fellow. Since September 2016 he is Coordinator R&D-strategy of Energy Ville, an institutional partnership between imec, VITO, KULeuven and University Hasselt focused on the themes of Smart Cities and Smart Grids.
Indian Institute of Technology (Banaras Hindu University), India
Nanostructured catalysts and their exploration provide recommended solutions for challenges regarding cost as well as in the factors influencing overall process optimization, due to their characteristic of high surface area to volume ratio which render outstanding properties with respect to the bulk catalyst. At the same time, increasing urbanization, population together with rise in living standards, have caused polymeric waste affecting the environment a chronic issue globally. Hence forth, the technological approach of nanocatalytic pyrolysis for conversion of polymeric waste into energy products is an alternative waste management and progress towards developing sustainable environment. Pyrolysis of waste polymer materials involves thermal decomposition in absence of air/oxygen, cracking their macromolecules into lower molecular weight ones, resulting the formation of a wide range of products from hydrogen, hydrocarbons to coke. It is also one of the tertiary recycling methods for plastics in accordance with ASTM D5033-00 which has divided plastic recycling methods into four types, based on the final result. In general, the variety of products obtained through pyrolysis can be classified into the non-condensable gas fraction, the liquid fraction consisting possible recovery of gasoline range hydrocarbons (C4-C12), kerosene (C10-C18), diesel (C12-C23), motor oil (C23-C40) and the third fraction of solids. While, nanocatalyzed pyrolysis is a promising solution to low thermal conductivity of polymers, therefore, promoting faster reactions in breaking the C-C bonds at lower temperatures, denoting less energy consumption and enabling increase in the process selectivity, generating higher added value products with increased yield.
Biography:
Dr. Poushpi Dwivedi is presently DST-SERB ‘National Post-Doctoral Fellowʼ (Project File No. PDF/2017/002264), at Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi, India. She obtained her B.Sc. Honours in Chemistry (2001) and M.Sc in Chemistry (2003) from Banaras Hindu University, India; M.Phil. (2009) from Madurai Kamraj University, India; Ph.D. (2015) from Motilal Nehru National Institute of Technology, India. She has worked as ‘Project Fellowʼ (2004) and ‘Post-Doctoral Fellowʼ (2017) in Department of Chemical Engineering & Technology, I.I.T. (B.H.U.), India; as guest faculty (2016) in Department of Chemistry, University of Allahabad, India. Research interests include: nanotechnology, nanomedicine, nanobiotechnology, green chemistry, analytical-techniques and energy.
Texas A&M University Qatar, Department of Chemistry, Qatar
The talk will focus around developing recyclable catalysts and analytical methods to study them. We will start with the discussion with synthesis, analysis and catalytic properties of Metal-Organic Frameworks (MOFs) with immobilized bidentate nitrogen ligands. This will include discussion on preparation of a number of alkyne functionalized ligands and their immobilization on the MOF surface through azide-alkyne “click” reaction. We will then shift the discussion to nanoparticle solubilization in nonpolar media with terminally functionalized Polyisobutylene (PIB) oligomers and application of this method to analyze MOF particles with immobilized complexes. We will show that MOF nanoparticles solubilized through this method can be interrogated through methods used for solution state analyses.
Keywords: Catalysis by Metal Organic Frameworks, nanoparticle solubilization.
Future University, Egypt
Nanotechnology is attracting great attention worldwide in biomedicine. Targeted therapy based on drug nanocarrier systems enhances the treatment of tumors and enables the development of targeted drug delivery systems.
In recent years, theranostics are emerging as the next generation of multifunctional nanomedicine to improve the therapeutic outcome of cancer therapy. Polymeric nanoparticles with targeting moieties containing magnetic nanoparticles as theranostic agents have considerable potential for the treatment of cancer.
The use of directed enzyme prodrug therapy (DEPT) has been investigated as a means to improve the tumor selectivity of therapeutics. Magnetic DEPT involves coupling the bioactive prodrug-activating enzyme to magnetic nanoparticles that are then selectively delivered to the tumor by applying an external magnetic field.
Gene therapy is an attractive method for meeting the needs for curing brain disorders, such as Alzheimerʼs disease and Parkinsonʼs disease. On the other hand, due to the fact that hepatocellular carcinoma (HCC) is resistant to standard chemotherapeutic agents, gene therapy appears to be a more effective cure for HCC patients.
Ultrasound-mediated drug delivery is a novel technique for enhancing the penetration of drugs into diseased tissue beds noninvasively. This technique is broadly appealing, given the potential of ultrasound to control drug delivery spatially and temporally in a noninvasive manner.
Biography:
Hussein O. Ammar is Holder of the First Class Golden Medal for Sciences and Arts and the recipient of the 2010 Appreciation State Prize in the realm of Advanced Technological Sciences. Professor Ammar is currently the Chairman, Pharmaceutical Technology Department, Faculty of Pharmaceutical Sciences and Pharmaceutical Industries, Future University in Egypt; formerly, Dean of the Pharmacy Division, National Research Centre, Cairo, Egypt. He has 127 research papers published in international scientific journals. These research papers cover most of the areas related to pharmaceutics, biopharmaceutics and pharmacokinetics. Design of new drug delivery systems is not beyond the scope of his interest.
1Adjunct Professor, University of Padova, (UNIPD), Italy
2Sao Paulo State University (UNESP), School of Dentistry, Brazil
The increasing interest for aesthetics in dental prosthesis has led to an increased use and research of biomaterials that mimic as much as possible the natural teeth behavior, both from the functional point of view and from the aesthetic one. The modern CAD/CAM technology is rapidly growing up, and with it a lot of brand new materials are being proposed on the market.
CAD/CAM blocs are being made of almost all the materials that are available for dental ceramics.
Materials such as E-Max Cad (Ivoclar), Suprinity (VITA), Enamic (VITA), Lava Ultimate (3Mespe) and Lava Plus (3Mespe) are nowadays the most used in dental practice, and a little confusion may occur when comes the time to choose one of them with a specific aim.
All of them present very good aesthetic characteristics, but they are pretty different concerning the mechanical, chemical and physical properties. Although the producer recommendation, there is a necessity in the literature to clarify the aesthetic, mechanical and physical properties of these CAD/CAM materials.
Here we present the differences in chemical composition and mechanical behavior of these new biomaterials used for daily dental practice.
Biography:
Francesco Saverio Ludovichetti was born in Padova in 1988 and graduated in dentistry in 2013 at the Padova University. In 2015 he started his “tri-lateral” international PhD in material engineering and dental material at the Universities of Sao Paolo (UNESP), Amsterdam (ACTA) and Padova (UNIPD). He has a specialization in Periodontics. Nowadays, he is one among the youngest Adjunct Professor at the UNIPD, he is working in his dental offices and his research line is about biomaterials in the oral environment. Speaker at national and international events, Visiting Researcher at the ACTA University (Amsterdam) and Visiting Professor at the Unievangelica University (Brasil).
Adjunct Professor at University of Padova, Department of Neurosciences, Italy. Visiting Professor at Unievangelica University, Department of Dental Materials, Anapolis, Brasil. Visiting Researcher at ACTA University, Department of Dental Materials, Amsterdam, The Netherlands. Postgraduate student, Department of Dental Materials and Prosthodontics, Sao Paulo State University (UNESP), School of Dentistry, Araraquara, Brazil.
Department of Chemistry and Institute for Shock Physics, Washington State University, USA
The application of high pressure and high temperature can facilitate the formation of new chemical bonds between two grossly mismatched lattices or dissimilar chemical species in solid states. Furthermore, the properties of solids are, to a first approximation, controlled by the interatomic distance and arrangement (or structure), which can be tuned precisely and substantially by the pressure, analogous to the composition in molecular alloys. The expected properties of these extended alloys are, therefore, similar in their novelty to single-component low Z extended solids, yet they can be tuned chemically by varying the composition, adding chemical impurities, or using specific structural templates. These chemical concepts can be used to control the bonding, structure, stability, and properties of dense extended solids made from low Z elemental mixtures. In this paper, we will describe our recent research efforts aimed at the development of dense carbon-based low Z organic framework (deCOF) structures with unique superconducting, optical and chemical energy storage properties. The specific examples of deCOF materials to be discussed will include solid hydrogen intercalated graphite and carbon dioxide storage in porous nanodiamond.
Biography:
Dr. Choong-Shik Yoo is Professor of Department of Chemistry, Institute for Shock Physics and Materials Science and Engineering at Washington State University. He received his PhD in Physical Chemistry in 1986 from UCLA and worked at Lawrence Livermore National Laboratory for twenty years prior to his current position at WSU. His research area of current interest is high-pressure materials chemistry to discover and develop carbon-based low dimensional structures, novel hybrid materials, high energy density materials, and superhard materials, utilizing diamond anvil cells, various laser spectroscopic methods, and novel X-ray diffraction and X-ray spectroscopy at third-generation synchrotron facilities.
Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, P. R. China
Molecular material aggregation structure is an important research direction in the development of material science, especially the development of two-dimensional molecular aggregated structure materials and heterostructure materials, understand the fundamental problems of aggregated structures in the optical, electrical, energy and catalytic fields and potential applications, represents the development trend of chemistry based the disciplinary scientific field. We mainly discuss some scientific problems in this field and the establishment of a series of molecular self-assembly and self-organization method using some basic concepts, combined with the molecular structure and growth characteristics, structure and energy matching principle. The controllable the aggregated structure of molecular materials from one dimension to two dimensions is realized. The properties in optical, electrical, energy and photoelectrical properties were also studied.
Biography:
Yuliang Li is a Professor at the Institute of Chemistry, Chinese Academy of Sciences. He has published more than 600 peer reviewed scientific articles and invited reviews in the journals, such as Nat. Commun. Acc. Chem. Res., Chem. Soc. Rev., J. Am. Chem. Soc., Angew. Chem. Int. Ed., PNAS and Adv. Mater. et al.. His research interests lie in the fields on design and synthesis of functional molecules, self-assembly methodologies of low dimension and large size molecular aggregations structures, chemistry of carbon and rich carbon, with particular focus on the design and synthesis of photo-electro-active molecular heterojuction materials and nanoscale and nano-structural materials.
Department of Chemistry, Ramnarain Ruia College, India
Silver amalgam has been used as a restorative material for the replacement of the decayed tooth structure for more than 150 years. The routine use of dental amalgam is gradually decreasing due to poor aesthetics for anterior restoration, mercury toxicity, and environmental consideration arising from mercury disposal, potential dental fracture, secondary caries, and marginal leakage. Physical properties of dental composites rely greatly on the particle size and filler volume. The hardness, compressive strength, elastic modulus and flexural strength etc increase while the polymerization shrinkage decreases as filler volume fraction increases[1]. In the last few years, the nanotechnology has played an important role in improving the clinical performance of dental resin composites. It deals with chemical and physical methods to produce nanoscale operational materials ranging in the size from 0.1 to 100 nm [2]. Nanocomposites contain filler particles with sizes in nano and micrometers i.e. hybrid in nature, are claimed to provide increased aesthetics, physical strength and durability. In order to improve mechanical properties of composites the surface of hybrid TiO2 nanoparticles was modified with coupling agent.
The aim of our work is to synthesize titanium nanoparticles in a green and rapid way to be used as fillers in hybrid form. These are modified with coupling agent APTES (3-Aminopropyltriethoxysilane) and combined with organic matrix to get dental restorative nanocomposite material by using light curing method. Citrus limon fruit peel extract was used as solvent for the synthesis of NPs. The surface modification of green synthesized hybrid TiO2 nanoparticles plays an important role to build up physical adhesion and covalent linkage of inorganic fillers and resin matrix. APTES is a universally used coupling agent that is responsible to protect fillers against fracture, to improve distribution and stress transfer from flexible organic matrix to stiffer and stronger inorganic filler particles. It also decreases water intake capacity of composites and minimizes wear. In addition, C=C functional group in APTES modified hybrid TiO2 takes part in polymerization process while curing. The result shows that an increase in filler content increases the mechanical properties of resin material significantly such as compressive strength, flexural strength, and elastic modulus etc. Polymerization shrinkage decreases when compared with the resin material with no filler content. These results are compared with the light curing resins available in the market and show enhancement in dental properties after addition of fillers. TiO2 are white in color, self-cleaning, and antimicrobial in nature. The development of such biocompatible materials in the field of restorative dentistry having aesthetic and antimicrobial properties has great potential for treating tooth decay and its prevention.
References:
[1] Ikejima I, Nomoto R, and McCabe JF Shear punch strength and flexural strength of model composites with varying filler volume fraction, particle size and silanation. Dent Mater. 2003, 19(3): 206-11.
[2] Kirk R, Othmer D, Kroschwitz J, Howe-Grant M. 1991. Encyclopedia of chemical technology. New York, : Wiley. 397 p.
Mapei S.p.A., Italy
This paper describes a new additive capable to effectively promote the development of early high strength and to reduce the water permeability of cementitious materials. Early high strength development is important in concrete technology to speed up the concrete production both in cold climates and in precast industry. The reduction of the permeability to water prevents the introduction of aggressive salts in the capillary pores of the cement paste and, therefore, increases the durability of concrete structures. The new admixture is an aqueous suspension of nano-sized metal transition polymeric silicate hydrate that catalyzes the homogeneous nucleation of calcium Silicate Hydrate (CSH) in the capillary pores of hydrating cement paste, promoting the early strength development. Furthermore, the crystallization of CSH in the capillary pores refines the capillary porosity of cement paste and significantly increases the resistance to water penetration under pressure. The mechanism of homogeneous crystallization of CSH was demonstrated by Synchrotron XRD micro-Tomography (XRD-µT) and by Scanning Electron Microscope (SEM) investigations. The effectiveness of the new admixture was demonstrated by mechanical tests on concrete specimens and by measuring the water permeability according to European Standard EN 12390-8. The new admixture increases the early strength development of concrete and can be used to produce concrete with outstanding mechanical performances and durability and it is highly effective in reducing the penetration of water, compared to other permeability reducing admixture admixtures, working with different mechanisms.
Department of Biotechnology, P.A. College of Engineering, India
Department of Biosciences, Jamia Millia Islamia University, India
Large bone defects caused by trauma, tumor resection, deformity, and infections are increasing year by year, but the rare resources for autogenous bone grafts and allograft rejections make it difficult to treat all of these deficiencies. In spite of high request in clinical medicine, natureʼs capability to self-organize the inorganic component with a preferred alignment in the bioorganic matrix is still not reproducible by synthetic techniques because of its complex nature. Therefore, in fields ranging from biology and chemistry to materials science and bioengineering a large developmental effort is essential in order to fabricate bone and dentin-like bio-composite materials, which may permit the in growth of hard tissues though improving mechanical properties with respect to the hard tissue regeneration. In recent years, certain attention has been paid to bio-mimetic approaches, which allow us to mimic such natural bio-inorganic and bio-organic composite materials. The main idea in bio-mimetic methodologies is to control and fabricate the morphology and composition of developed biomaterials, in which the nano crystallites of inorganic compounds are spread with special orientation in the organic matrices due to its large potential in biomedical applications. In the present work, we successfully mimicked electrospun bio-nanocomposit fibers on the basis of Poly Vinyl Alcohol (PVA) as matrix and Hydroxy Apatite (HA) nanoparticles with a highly anisotropic three-dimensional structure, microscopically the same as a substructure of bone. We have used two-step methodology that combines an in situ co-precipitation synthesis route with electrospinning process to prepare a unique type of bio-mimetic nanocomposite nanofibers of HA/PVA. The fibers produced by the electrospinning machine were in 100-200 nm. The result obtained from UTM analysis highlights the great tensile strength and youngʼs modules of the nanofibers. A combination of structural, mechanical and biological properties of bone graft play a critical role in cell seeding, proliferation and new tissue formation in orthopaedic research. Nano-biomaterials should promote cell adhesion and be optimized for ECM production, mineralization and subsequent tissue regeneration. Hence, electrospun biomimetic HA/PVA/CNT nanofibers hold great potential for adhesion, proliferation and mineralization of osteoblasts and are favourable bio-composite scaffolds suitable for bone tissue redevelopment.
Biography:
Dr. Khalid Parwez, is working as an Associate Professor in the department of Biotechnology, P.A. College of Engineering, Mangalore and as guest teacher in the department of Biosciences, Jamia Millia Islamia, New Delhi. He has been teaching undergraduate and post graduate since 2009. His area of research includes Nanomaterial synthesis and characterization, nanocomposite (Advance nanomaterials), Nanomaterials as diagnostic tools and bone tissue engineering. He received PhD degree from Yenepoya University in the department of Allied Health and Basic Sciences in 2015 and Master of Science degree from Manipal University in 2008. He has total 14 research paper published in peer reviewed journals, attended many national and international conferences, given invited talk, received Young Scientist award from state government for the year 2015-16. Received a research grant from Govt. of India for three years from 2017-2019 for development of carbon nanotubes based on diagnostic kit for Leptospirosis and currently working on it.
1IMDEA Materials Institute, Spain
2Universidad Carlos III de Madrid, Spain
The addition of Zr to ODS ferritic steels provides a way to enhance the formation of finer and more stable oxides than those obtained in ODS steels with Y-Ti-Al addition. The formation of zirconium rich nano-oxides may prevent grain growth and refine the final grain size leading to an improvement of the mechanical properties. In addition, another advantage is based on the fact that Zr leads to an improvement in the resistance to the irradiation damage since its oxides exhibit good irradiation tolerance and thermal stability.
In the present investigation, a 14Cr-5Al-3W alloy is modified by adding Ti, Y2O3 and Zr in two different ways, as pure elemental Zr powder or as ultrafine ZrO2 powder. These ferritic ODS steels are processed by high energy milling in a horizontal attritor and subsequent consolidation by SPS. Special emphasis is focused on understanding the differences in the final properties achieved after consolidation depending on the Zr source, and thus on the amount of oxygen available for re-precipitation of oxides during SPS. In order to assess the microstructural properties of these alloys, SEM studies coupled to EBSD mapping are performed. Finally, hardness and micro-tensile tests are carried out to assess the differences in the mechanical properties.
Keywords: 14Cr ODS steel; Zirconium; Zirconia; Nanostructured material; SPS; Mechanical properties.
Biography:
Dr. Andrea Garcia-Junceda graduated in both Chemistry and Materials Engineering at the Complutense University of Madrid. She is currently the head leader of the Solid State Processing Group at IMDEA Materials Institute. This group is collaborating with important research centers and companies in the field of powder metallurgy. The main goal of her group is focused on the design and development of advanced alloys with outstanding properties. She is co-author of 22 journal publications. She has been involved in 12 competitive research projects. At the present time, she is the principal investigator of the FP7 project entitled “PILOTMANU”.
Head of the Department “Advanced Materials and Surfaces”
Empa, Swiss Federal Laboratories for Materials Science and Research, Switzerland
The development of carbon based nanoelectronics has been an important research goal ever since the discovery of carbon nanotubes (CNT) in 1991 and was boosted even more by the isolation of graphene in 2004. For digital electronics the biggest hurdle is the lack of control in the atomically precise synthesis of these carbon nanomaterials. For pure carbon nanotubes the chirality determines the electronic properties (metallic vs. semiconducting) and isomerically pure single walled carbon nanotubes (SWCNTs) of a specific chirality are thus needed to fully exploit their technological potential.
The situation is similar for graphene. Graphene is a semimetal and not a semiconductor. The lack of the electronic band gap makes it impossible to build a field effect transistor with a well-defined off-state. Theory predicts that graphene tailored into nanometer-wide ribbons, termed graphene nanoribbons (GNRs), gives rise to electronic properties that differ strongly from those of the semi-metallic parent material. These properties include sizable electronic band gaps due to quantum confinement and edge effects, as well as the spatial separation of spin channels due to spin-polarized edge states in zigzag GNRs. To preserve the outstanding electronic transport properties of graphene in the GNR the whole structure including the edges of the GNR has to be free from atomically defects. We have developed a simple method for the production of atomically precise GNRs of different topologies and widths, which uses surface-assisted coupling of molecular precursors into linear polyphenylenes and their subsequent cyclodehydrogenation. The topology, width and edge periphery of the GNRs are defined by the structure of the precursor monomers, which gives access to a wide range of different GNRs with particular electronic properties.
Biography:
Pierangelo Groning joined Brown Boveri Company, after he got his master degree in Electrical Engineering in 1981, where he developed high power electronic converters for railways. After five years in the industry he went back to academia and studied Physics at the University of Fribourg (CH), where he obtained his PhD in Solid State Physics in 1993. From 1993 to 2002 he was Staff Scientist and Lecturer at the University of Fribourg (CH). In 2002 he joined the Swiss Federal Institute for Material Science and Technology (Empa). Since 2006 Dr. Gröning is head of the Department “Advanced Materials and Surfaces”, director of the strategic research focus area “Nanostructured Materials” and member of the board of directors at Empa.
Korea Advanced Institute of Science and Technology, Republic of Korea
We have explored a new mechanism for switching magnetism and superconductivity in a magnetically frustrated iron-based superconductor using spin-polarized scanning tunneling microscopy (SPSTM)[1]. Our SPSTM study on single crystal Sr2VO3FeAs made of alternating self-assembled FeAs monolayer and Sr2VO3 bilayers shows that a spin-polarized tunneling current can switch the FeAs-layer magnetism into a non-trivial C4 (2×2) order, which cannot be achieved by thermal excitation with unpolarized current. Our tunneling spectroscopy study shows that the induced C4 (2×2) order has characteristics of plaquette antiferromagnetic order in the Fe layer and strongly suppresses superconductivity. Also, thermal agitation beyond the bulk Fe spin ordering temperature erases the C4 state. These results suggest a new possibility of switching local superconductivity by changing the symmetry of magnetic order with spin-polarized and unpolarized tunneling currents in iron-based superconductors[2]. We also performed high-resolution quasiparticle interference (QPI) measurements, self-consistent BCS-theory-based QPI simulations and a detailed e-ph coupling analysis to provide direct atomic-scale proofs of enhancement of iron-based superconductivity due to the BCS mechanism based on forward-scattering interfacial phonons[3].
[1] J.-O. Jung et al., Rev. Sci. Instrum. 88, 103702 (2017)
[2] S. Choi et al., Phys. Rev. Lett. 119, 227001 (2017)
[3] S. Choi et al., Phys. Rev. Lett. 119, 107003 (2017)
Biography:
Prof. Jhinhwan Lee grew up in Republic of Korea and received his Bachelorʼs degree from Seoul National University in 1995. After he obtained his Ph.D. degree from Seoul National University in 2002, he joined Professor J. C. Davisʼ Laboratory at Cornell University as a Postdoctoral Associate in 2004 and was appointed Research Associate in 2007. Jhinhwan Lee went to Korea Advanced Institute of Science and Technology as Assistant Professor in 2009 and began his life-long investigations on magnetism and unconventional superconductivity. He was awarded with Bombee Physics Award in 2004 and Albert Nelson Marquis Lifetime Achievement Award in 2018.
1University Paris Est, IFSTTAR, France
2Laboratory of Physics of Interfaces and Thin Films, Ecole Polytechnique Palaiseau, France
3Department of Energy Science, Sungkyunkwan University, Korea
In this work, we study the properties of graphene nanoplatelets as an effective anticorrosion coating for aluminum substrate in 0.5 M NaCl at room temperature (25 °C). Scanning and transmission electron microscopy and Raman spectroscopy reveal the high quality multilayer graphene nanoplatelets. The modification of the corrosion resistance characteristic were investigated by open circuit potential (OCP), followed by electrochemical tests such as potentiodynamic polarization (Tafel curves) and electrochemical impedance spectroscopy (EIS). The electrochemical results show that the graphene nanoplatelets provides effective resistance against corrosive medium. Scanning electron microscopy (SEM), Raman spectroscopy and Energy Dispersive X-ray (EDX) studies carried after immersion in corrosive medium confirm that graphene coated aluminum surface is well protected compared to the uncoated substrate.
Biography:
Dr. Fatima Bouanis, physico-chemist, received the masterʼs degree from “Ecole Nationale Superieure de Chimie de Lille” and the PhD from “University des Sciences et Technologies de Lille” in 2009. From 2009 to 2011, she worked jointly at LPICM (Laboratoire de Physique des Interfaces et des Couches Minces)-Ecole Polytechnique France and ICMMO (Institut the Chimie Moleculaire et des Materiaux dʼOrsay)-France as a post-doctoral fellow on carbon nanotube electronics and from 2011 to 2012, she worked as post-doctoral “sensors based carbon nanotubes” at LPICM and PSA. Since 2012, she is researcher at IFSTTAR-France within NACRE (LPICM-LISIS) joint research team and she is a member of Sense-City project team. Her research focuses on sp2 carbon-based selective sensing for urban environmental applications. She is involved in carbon nanotubes and graphene synthesis and collective organisation for advanced electronics and novel devices (CNT-based FETS, gas/biological sensors, Memristors, Inverters...). She supervised two PhD students, 1 post-doc and has supervised several master students. F. Bouanis authored or co-authored 11 peer-reviewed publications, and 2 patents. She is member of management committee of COST ACTION CA 15107 Multi Comp “Multi-Functional Nano-Carbon Composite Materials Network”.
1Melbourne Centre for Nanofabrication, Australia
2Monash Institute for Pharmaceutical Sciences, Monash University, Australia
Targeted approaches to deliver anti-cancer drugs have the potential to achieve improved efficacy and at the same time reduced side effects. In fact, this is one of the cornerstones of nanomedicine.
We are exploring the use of high porosity biodegradable porous silicon and genetically engineered biosilica nanoparticles that are loaded with chemotherapy drugs or siRNA and also display on the particleʼs periphery targeting moieties such as cell-surface antibodies recognising cognate ligands highly expressed on the surface of tumour cells. One approach centers around porous silicon nanodiscs. The process relies on a combination of colloidal lithography and metal-assisted chemical etching. Height and diameter of the pSi nanodiscs can be easily adjusted. The nanodiscs are degradable in physiological milieu and are non-toxic to mammalian cells. In order to highlight the potential of the pSi nanodiscs in drug delivery, we carried out an in vitro investigation which involved loading of nanodiscs with the anti-cancer agent camptothecin and functionalization of the nanodisc periphery with an antibody that targets receptors on the surface of neuroblastoma cells. The thus prepared nanocarriers were found to selectively attach to and kill cancer cells. In a second approach, we used natural nanoporous biosilica from the diatom Thalassiosira pseudonana. The biosilica was genetically engineered to display GB1, an IgG binding domain of protein G, on the biosilica surface, which allowed for the attachment of cancer cell targeting antibodies and the adsorption of nanoparticles loaded with anti-cancer drugs. In a final approach, we engineered porous silicon nanoparticles to deliver siRNA to successfully downregulate drug transporter proteins in tumour cells.
Biography:
Maria Alba Martin is pursuing postdoctoral studies under the guidance of Professor Nicolas Voelcker. Professor Nicolas Voelcker is the Scientific Director of the Melbourne Centre for Nanofabrication, Professor at the Monash Institute of Pharmaceutical Sciences at Monash University and Science Leader at the Commonwealth Scientific and Industrial Research Organisation (CSIRO). His key research interest lies in the fabrication and surface modification of porous semiconductor materials for applications in biosensors, biochips, biomaterials and drug delivery. A core research activity in his laboratory is the study of porous silicon based nanostructures and their surface chemistry. A current focus is the development of new nanostructured materials for biosensors, biochips, biomaterials and drug delivery.
He has authored over 330 peer-reviewed journal articles with over 7000 citations.
1Department of Chemistry, Duke University, USA
2Army Aviation & Missile RD&E Center, USA
3Optics Group, Department of Applied Physics, University of Cantabria, Spain
4Department of Physics, Duke University, USA
In plasmon-enhanced heterogeneous catalysis, illumination accelerates reaction rates by generating hot carriers and hot surfaces in the constituent nanostructured metals. In order to understand how photo-generated carriers enhance the non-thermal reaction rate, the effects of local heating and thermal gradients in the catalyst bed must be confidently and quantitatively characterized. This is a challenging task considering the conflating effects of light absorption, heat transport, and reaction energetics. Here, we introduce a methodology to distinguish the thermal and non-thermal contributions from plasmon-enhanced catalysts, demonstrated by illuminated rhodium nanoparticles on oxide supports to catalyze the CO2 methanation reaction. By simultaneously measuring the total reaction rate and the temperature gradient of the catalyst bed, the effective thermal reaction rate may be extracted. The residual non-thermal rate of the plasmon-enhanced reaction is found to grow with a super-linear dependence on illumination intensity, and its apparent quantum efficiency reaches ~46% on a Rh/TiO2 catalyst at a surface temperature of 350 °C. Heat and light are shown to work synergistically in these reactions: the higher the temperature, the higher the non-thermal efficiency in plasmon-enhanced catalysis.
Biography:
Jie Liu is currently the George B Geller Professor of Chemistry at Duke University. He earned a B.S. in Chemistry from Shandong University in 1987 and a Ph.D. in Chemistry from Harvard University in 1996. His research interests include synthesis and chemical functionalization of nanomaterials, plasmonic catalysis, nanoelectronic devices, scanning probe microscopy, and carbon nanomaterials. As a faculty member, Professor Liu has received the DuPont Young Professor Award, Outstanding Oversea Young Investigator Award from NSF-China, Ralph E. Powe Junior Faculty Enhancement Award from Oak Ridge Associated Universities, and Bass Professorship from Duke University for excellence in teaching and research. He is elected as a Fellow in AAAS (2013), APS (2014) and RSC (2013). He also serves as an associate editor for RSC journal Nanoscale since 2012.
1Laboratory of Functional and Molecular Imaging & Nanomedicine, Department of Radiology and Imaging Sciences, Emory University School of Medicine, USA
2Division of Research, GA campus-Philadelphia College of Osteopathic Medicine, USA
3Department of Biomedical Sciences, GA campus-Philadelphia College of Osteopathic Medicine, USA
Alzheimerʼs Disease (AD) is a neurodegenerative disease with diagnostic and therapeutic challenges. The currently available diagnostic tools are expensive, invasive, and insufficient for early screening. We have constructed a novel, simple and efficient method for the detection of early AD using anti-biofouling magnetic nanomaterials. The anti-biofouling polymer coated Iron Oxide Nanoparticles and their targeting antibody conjugates were prepared as described in the literature. The Fluoresce in Isothiocyanate (FITC) labeled amyloid-beta peptide 1-40 [Aβ(1–40)] and Tetramethylrhodamine-5-(and 6)-isothiocyanate (TRITC) labeled peptide 1-42 [Aβ(1–42)] were dissolved in artificial cerebrospinal fluid (CSF) or Phosphate Buffered Saline (PBS) with Fetal Bovine Serum (FBS) at 50 mg/mL to mimic the human CSF and serum environment respectively. They were then incubated with antibody (Ab)- conjugated IONPs (at final iron concentration of 0.2 mg/mL) or antibody-conjugated Dynabeads for 3 hours before magnetic separation of particles. The separation efficiency (SE) was calculated as the weight ratio of captured peptide to spiked. The protein quantification was verified using micro bicinchoninic acid (BCA) protein assay kit. Furthermore, insulin was purposely added to artificial CSF and PBS with FBS as interference to demonstrate the capture specificity of Ab-conjugated IONPs. The SE of antibiofouling IONP for Aβ(1–40) in artificial CSF at 0.1, 0.2, 0.5, 1, 2, 5, and 10 microgram/mL were found to be 97, 96.6, 97.7, 92.2, 88.9, 91.4, 89.9% using fluorescence signal and at 98, 95.6, 98.5, 90.2, 93.6, 88.7, and 91.1% with micro BCA protein assay kit. The SE for IONP for Aβ(1–40) in PBS with FBS at the same concentrations were also in the range of 88-95%. When insulin was added to Aβ(1–40) mixture, the separation efficiency of insulin for IONP was only 4.5, 4.7, 6.2, 6.5, 7.7, 9.8, and 12.3% while dynabeads showed no difference in the separation efficiency for both Aβ(1–40) and insulin. Similar results were obtained for Aβ(1–42) and IONP with minimal isolation of insulin in both artificial CSF and PBS with FBS. Dynabeads again showed indiscriminate separation of Aβ(1–42) and insulin. The antibody conjugated IONP consistently exhibited separation efficiency above 88% for Aβ(1–40), and Aβ(1–42) in both artificial CSF and in PBS containing FBS with good reproducibility. Its ability to selectively detect AD markers were also validated with interference with insulin, demonstrating the IONPʼs potential application for early AD diagnosis in human serum and CSF.
Biography:
Esther Lim, MD, MBA is currently an associate professor of radiology at PCOM and works in collaboration with Dr. Hui Mao, PhD, Professor of Radiology and Biomedical Engineering and the Director for the Molecular Imaging, Biomarkers, and Probe Development at Emory University. Dr. Yuanchen Li, PhD is a staff scientist at Emory University School of Medicine with expertise in anti-biofouling polymer synthesis for nanomaterial coating and biomarker targeted imaging, drug delivery and therapy.
1Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China
2Institute of Chemistry, Chinese Academy of Sciences, China
Although the Li capacity can be improved greatly with these different dimensionalities and morphologies, the nature of the Li-intercalated layer does not change significantly when compared to graphite. Graphdiyne (GDY) is a new carbon allotrope that was only synthesized recently. GDY is composed of sp2- and sp-hybridized carbon atoms and is predicted to be the most stable of the various diacetylenic non-natural carbon allotropes. Here, we will report the application of GDY as high efficiency lithium storage materials and elucidate the method of lithium storage in multilayer GDY (Fig 1)[1-3]. Lithium-ion batteries featuring GDY-based electrode exhibit excellent electrochemical performance, including high specific capacities, outstanding rate performances, and a long cycle lives. We obtained reversible capacities of up to 901 mAh/g after 400 cycles at a current density of 100 mA/g. At an even higher current density of 2 A/g, cells incorporating GDY-based electrodes retained a high specific capacity of 420 mAh/g after 1000 cycles. We hope that designing and preparing novel carbon-based materials with large pores will open up new approaches for the development of Li storage materials exhibiting high capacities and excellent cycling stabilities, thereby satisfying the future requirements of next-generation Li storage batteries.
[1] Changshui Huang, Shengliang Zhang, Huibiao Liu, Yongjun Li, Guanglei, Cui, Yuliang Li, Graphdiyne for high capacity and long-life lithium storage. Nano Energy, 11, pp 481-489, 2015.
[2] Huiping Du, HuiYang, Changshui Huang*, Jianjiang He, Huibiao Liu, Yuliang Li, Graphdiyne applied for lithium-ion capacitors displaying high power and energy densities. Nano Energy, 22, pp 615-622, 2016.
[3] Ning Wang, Jianjiang He, Zeyi Tu, Ze yang, Fuhua Zhao, Xiaodong Li, Changshui Huang*, Kun Wang, Tonggang Jiu, Yuanping Yi and Yuliang Li. Synthesis of Chlorine-substituted Graphdiyne and Its Application for Lithium-ion Storage. Angew. Chem. Int. Ed, 56, pp10740-10745, 2017.
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China
The properties of electron transport layers play a crucial role in determining the performance of perovskite solar cells. Here we reported the effect of graphdiyne doped into both PCBM and ZnO films of perovskite solar cells with an inverted structure based on MAPbI3 for the first time. A high efficiency of 20.0% was achieved in MAPbI3 perovskite solar cells with the J-V hysteresis and stability significantly improved as well. It reveals that the employment of dual-doping of graphdiyne not only brought out an increase of electrical conductivity, electron mobility, and charge extraction ability in the electron transport layers, but improved film morphology of the electron transport layers and reduced charge recombination which contribute to fill factor enhancement. This study indicates that dual doping graphdiyne is a promising strategy to optimize the performance of perovskite solar cells.
Biography:
Tonggang Jiu, Professor, currently serves as the group leader of the Carbon Based Photovaltaic Research Team, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences (CAS). He received his Ph.D. degree from the Institute of Chemistry, CAS in 2006. From 2007 to 2012, he continued his research at CEA-Grenoble, Eindhoven University of Technology and University of Alberta where he was mainly engaged in nanomaterials based solar cells. In recent years, he has focused on Graphdiyne based photovaltaic devices, and published more than 40 papers in SCI journals. In 2012, Prof. Jiu was honored as a member of Youth Innovation Promotion Association, CAS.
1Environmental Toxicology Program, University of California, USA
2Department of Chemistry, University of California, USA
Reactive oxygen species (ROS) are indicators of oxidative stress in biological systems that should be monitored closely due to its great impact on physiological processes including signal transduction, gene expression and cell apoptosis. In addition, some of the ROS, like H2O2, are involved in many enzymatic reactions, and can be utilized to enable the detection of small molecular biomarkers like glucose and cholesterol, which cannot be detected easily using non-enzymatic approaches. In the present work, the ROS-responsive hydrogel microparticles, i.e. microgels, have been designed and fabricated. Microgel can protect the enclosed, ultrafine (diameters < 5 nm) ZnS nanoparticles (NPs) from dissolution; but the highly porous gel structure is permeable to the stable ROS like H2O2 which can rapidly react with the small NPs. The reaction releases free Zn2+ that can turn on the Zn2+ specific dye, Fluozin-3, and produce strong fluorescence. The reactivity towards ROS of the microgel can be tuned by changing the NP composition: adding a trace amount of Cu2+ can greatly enhance the fluorescence signal produced by H2O2, and permit detection of as low as 80 nM H2O2, lower than previously reported, fluorescence-based sensors. The excellent sensitivity towards H2O2 makes the ROS-responsive microgel a very useful tool for detection of glucose and cholesterol in human serum. When coupled with glucose oxidase and cholesterol oxidase, the sensor can achieve low limits of detection of 0.52 µM and 0.77 µM for glucose and cholesterol, respectively, which significantly reduces sample consumption. Our design of the ROS-responsive microgel is very unique and provides the advantages of simple and flexible fabrication, bright and stable signals, high structural stability, and rapid response towards stimulus, carrying high promise in biomedical applications.
Biography:
Dr. Wenwan Zhong is Professor of Analytical Chemistry at the University of California, Riverside. Dr. Zhongʼs research focuses on the development and application of microscale separation and sensors for biomarker discovery, functional study, and detection. Her current work covers three distinct areas: the use of microfluidics and flow field flow fractionation for analysis of circulating biomarkers; the use of capillary electrophoresis, mass spectrometry, and optical spectroscopy for assessment of the interaction between engineered nanomaterials and biomolecules; and the use of synthetic receptors for exploration of post-translational modifications in proteins.
1Waterloo Institute for Nanotechnology, University of Waterloo, Canada
2Nanodevice Solutions Inc., Canada
A serious issue with AFM is the intrinsic artifact in the AFM image when mapping a non-flat surface (e.g. a deep and narrow hole/trench). The natural solution to overcome this issue is by using thin and high aspect ratio (HAR) tips that can follow the sample surface more precisely. At present, commercial HAR tips are mostly fabricated by the very slow and costly FIB sharpening process, and the very high price greatly limits its wide-spread application. Here we will report a batch fabrication process, which can process an entire wafer of regular (low aspect ratio, low cost) tips into HAR ones, without using any lithography method.
A second issue is the tip location relative to the cantilever. Because of alignment accuracy in photolithography, most commercial AFM probes have tips 10-30 µm away from the very end of the cantilever, and it is thus impossible to know where exactly the tip is because the camera in an AFM system shows only the backside of the AFM cantilever. So the initial scanning area must be set very large in order to ensure that the area of interest is within the scanning field. It is therefore very desirable for the tip to be located at the very end of the cantilever so that it can be viewed clearly by the optical microscope of the AFM system. Here we will report a low-cost batch fabrication method to produce such “edge tip” where the tip is located at the very end of the cantilever.
Biography:
Prof. Bo Cui received PhD from Princeton University. In 2008 he joined the University of Waterloo as a professor. He currently leads the Waterloo Nanofabrication Group with 18 graduate students/postdocs. His research focus on nanofabrication technologies and its applications. In particular, his research in special AFM probe fabrication has led to two startup companies (Nanodevice Solutions Inc., and TZNano). He is the recipient of the Dobbin Scholarship. He authored 95 peer reviewed journal publications, 6 patents, three book chapters, and one book titled “Recent advances in nanofabrication techniques and applications”. He is the Associate Editor for Nanoscale Research Letters.
National Institute of Material Physics, Romania
Recently, the researchers focused their attention on the preparation and characterization of the core-shell radial heterojunction nanowires in order to develop novel devices based on such one-dimensional nanostructures. These core-shell nanowires are featured by a large interface area which can facilitate the formation of electron-hole pairs or their recombination leading to innovative applications solar cells, photodetectors, photocatalysis, electronic devices, etc. ZnO is an n-type semiconductor with a wide direct band gap of 3.3 eV, while CuO is a p-type semiconductor with a narrow indirect band gap of 1.2 eV. Thus, by coupling the two semiconductors into core-shell radial heterojunction nanowires, an enhancement of their properties can results by mutual transfer of charge carriers (electrons and holes) from one semiconductor to another.
In this work, arrays of core-shell nanowires based on ZnO and CuO have been obtained by combining two techniques, thermal oxidation in air and RF magnetron sputtering. Structural, compositional, morphological, optical and electrical properties of the obtained core-shell nanowires were analyzed by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, diffusive reflectance, photoluminescence and current-voltage measurements, respectively. Further, the electrical properties of individual core-shell radial heterojunction nanowires were investigated using lithographic techniques such as photolithography, electron beam lithography and focused ion beam induced deposition and thin films deposition techniques like RF magnetron sputtering and thermal vacuum evaporation. In this way, field effect transistors and diodes based on single core-shell heterojunction nanowires were fabricated for potential applications in optoelectronic field.
Acknowledgement: This work has been funded by the Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI), Romania, Project code: PN-III-P2-2.1-PED-2016-1249.
Biography:
Dr. Andreea Costas has received her doctoral degree in 2016 at the University of Bucharest in the field of Condensed Matter Physics. She is currently working as a young researcher at National Institute of Materials Physics in the Laboratory of Multifunctional Materials and Structures. Until now she has 10 publications, an H-index of 4 and was involved as a team member in more than five national research projects.
Department of Biotechnology, Thiruvalluvar University, India
The objective of the study was to determine the biofilm degradation potential of sliver nano particles (Ag NPs) synthesized using the aqueous bark extract of Alstonia scholaris on PVC substrates that are used in water distribution system. The phytogenic AgNPs revealed potent antimicrobial effect. The application of the antimicrobial effective AgNPs, to contain the Biofilm Formation on PVC Substrates was carried out by infusing the AgNPs in an epoxy resin to develop functionalized epoxy nanocomposites which can be used as surface coating on PVC substrates. Precautions were taken using solvent heating process using methyl ethyl ketone and xylene to avoid agglomeration resulting in poor dispersion of nanoparticles.
The surface morphology and mechanical properties of these coatings containing phytogenic AgNPs were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Epifluorescence microscopy.
The anti biofilm efficacy of the functionalized epoxy nanocomposite coatings on PVC was investigated by total viable counts (CFU/Cm2) from day one to twenty five day. The results revealed that the phytogenic AgNPS infused epoxy coating, improved the micro structure of the matrix and thus enhanced the anti biofilm performance. Further, the antimicrobial kinetic studies revealed that the effective inhibition of Biofilm Formation on PVC Substrates coated with the epoxy nano composites.
Therefore the funcionalized epoxy nano composites surface coatings on PVC substrates is an effective economical and eco friendly alternative to prevent Biofilm Formation on PVC Substrates used in water distribution systems.
Biography:
Dr. Ernest David, is Professor and Head of the Department of Biotechnology, at Thiruvalluvar University, in the Fort city of Vellore, Tamil Nadu. He pursued undergraduate education from his native state, Andhra Pradesh, and Postgraduate studies at University of Pune. He obtained his Research Degrees from Sri Venkateswara University, Tirupati, Andhra Pradesh in 1984.
He served as Senior Research Officer at Central Silk Board for two Years. His passion for teaching and research lead to appointment as Assistant Professor at Voorhees College, Vellore from September 1988. He received the “Young Scientist Award” from the Government of Tamil Nadu, in 1994. He also received two grants from University Grants Commission for major research projects. He visited USA, China and Thailand and presented research papers in the Conferences. Eventually he was selected to the post of Professor, at Thiruvalluvar University in May, 2011 where he currently is. He was selected for “Academic Exchange Programme” at Corvenius University, Budapest, Hungary in November, 2011.
He has guided 25 students for Research programmes viz. M.Phil. and Ph.D. and published 75 research papers. In addition to his Academic position, he also holds portfolio as Director, Institutional Quality Assessment Cell at his University.
University of Connecticut, USA
Currently, many medical diagnostic procedures are inefficient and inaccessible to a large population in the world because these procedures require advanced and expensive testing equipment as well as labor-intensive protocols to be carried out by a trained technician. Here, we present a versatile platform technology designed for point-of-care diagnostics which uses magnetic levitation to separate cells on the basis of their densities and measure the density distribution of the cells in a patient sample. We have demonstrated its versatility in the ability to measure density change in cells for a range of diagnostic applications including sickle cell disease diagnosis, white blood cell cytometry, and rare object detection in biological samples.
Biography:
Dr. Savas Tasoglu joined the University of Connecticut in 2014 as an Assistant Professor in the Department of Mechanical Engineering. He received his Ph.D. in 2011 from UC Berkeley, with a research focus on transport phenomena and pharmacokinetics of anti-HIV microbicide drug delivery. Dr. Tasoglu held a postdoctoral appointment at Harvard Medical School and Harvard-MIT Division of Health Sciences and Technology until he joined UConn in 2014. His current research interests are: point-of-care diagnostic devices, bioprinting, magnetic focusing and levitation. His work has been featured at the cover of Advanced Materials, Small, Trends in Biotechnology, and Physics of Fluids and highlighted in Nature, Nature Physics, Nature Medicine, Boston Globe, Reuters Health, and Boston Magazine.
School of Electrical Engineering, Korea University, South Korea
It is well known that contact resistance has been a critical issue in determining the performance of complementary metal–oxide–semiconductor (CMOS) reaching physical limits. Conventional Ohmic contact techniques, however, have hindered rather than helped the development of CMOS technology reaching its limits of scaling. Here, a novel conductive filament metal–interlayer–semiconductor (CF-MIS) contact which achieves ultra-low contact resistance is investigated for potential applications in various nanoelectronic devices in lieu of conventional Ohmic contacts. This universal and innovative technique, CF-MIS contact, forming the CFs to provide a quantity of electron paths as well as tuning Schottky barrier height (SBH) of semiconductor, is firstly introduced. The SBH of the semiconductor is lowered by inserting ultra-thin interlayers such as AL2O3, ZnO, and TiO2. Those interlayers can unpin the Fermi-level by alleviating the metal-induced gap states (MIGS) at the semiconductor surface. Moreover, CFs are formed in the interlayers to significantly increase conductivity between the metal and the semiconductor. The proposed CF-MIS contact achieves ultra-low specific contact resistivity, exhibiting up to ~×700, 000 reduction compared to that of the conventional metal-semiconductor (MS) contact. This study proves the viability of CF-MIS contacts for future Ohmic contact schemes, and that they can easily be extended to mainstream electronic nanodevices that suffer from significant contact resistance problems.
Biography:
Seung-Hwan Kim received his B.S. degree in Electrical Engineering from Dongguk University, Seoul, South Korea, in 2014. He is currently pursuing his Ph.D. degree in School of Electrical Engineering from Korea University. His current research interests include CMOS technology and future memory.
School of Electrical Engineering, Korea University, South Korea
An atomic switch, conductive bridge random access memory (CBRAM), is an electro-ionic resistive switching device that formation/rupture of conduction channel with metal ions, such as Ag and Cu, determines the ON/OFF state. Atomic switches are promising future information processing device because of its simple structure, great integrability, low power operation, and selectivity of volatile/nonvolatile operation. Especially, volatile threshold switching atomic switches have gained significant attention in recent years. However, instability of volatile switching operation is pointed out as a crucial problem. In this study, we propose a highly stable Pt/SiOxNy/Ag volatile threshold switching device that operates at 0.2V with a high on/off ratio (~105). As a nitrogen doping concentration becomes higher, both forming voltage and threshold voltage tends to decrease, which is explained by increased nitrogen trap density. More to the point, the threshold voltage variation was found to be reduced. In sum, the effect of nitrogen doping in volatile threshold switching device can increase reliability of the devices with remaining those electrical characteristics compared to Pt/SiO2/Ag device. This research proved the effect of nitrogen doping in volatile threshold switching device with simple method, and it is expected to be applicable to other oxide-based volatile threshold switching devices. Moreover, the proposed devices can be extended to atomic switch-based logic circuit for future information processing applications.
Biography:
Jae-hyeun Park received his B.S. degree in Electrical Engineering from Korea University, Seoul, South Korea, in 2017. He is currently pursuing his M.S. degree in School of Electrical Engineering from Korea University. His current research interests include future memory and neuromorphic system.
Technion-Israel Institute of Technology, Israel
Short-period superlattices, based on semiconductor or oxide layers, have wide range of applications from infrared imaging to giant magneto-resistance devices. Some of them require deposition of a nm-thick sub-layers. In these systems, the interface quality becomes crucial for device functioning. Most common imperfections are related to atomic intermixing during growth that is difficult to probe on such short length scales. We use for this purpose advanced characterization techniques, which include high-resolution transmission electron microscopy (HRTEM) for lattice imaging and, especially, high-angle annular dark field (HAADF) in scanning transmission electron microscopy (STEM) for Z-contrast imaging, scanning tunneling microscopy (STM) for direct counting of atomic substitutions on freshly fractured surfaces, local electrode atom probe (LEAP) tomography for three-dimensional chemical analysis with a sub-nm-resolution, and high-resolution X-ray diffraction (HRXRD) for spatial profiling of inter-planar spacings. In the current work, we apply all these methods to study atomic intermixing in short-period GaSb/InSb/InAs/InSb superlattices for infrared detectors. We discuss the suitability, complementarity, uniqueness, and limitations of the above mentioned characterization techniques.
Korea University, South Korea
We have developed the MoS2 phototransistors using Ge back gate electrode, which can detect the infrared light using a novel light detecting mechanism in MoS2 phototransistors for the first time. Since the phototransistor can detect the visible light as same as typical MoS2 phototransistor, the MoS2 phototransistor with Ge back gate has a considerable wide detection range from visible to infrared. The mechanisms of detection in visible light and infrared light have been successfully investigated. The infrared detection has been verified by the comparison between Si and Ge back gate electrodes. In the infrared light, the phototransistor operates by the mechanism of threshold voltage shifts through modification of band bending at the Ge-SiO2 interface caused by accumulated electrons, and the values are from -0.432 to -0.212 V. This novel light detecting mechanism can be applied to all TMDs-based phototransistors regardless of the channel materials because the back gate absorbs the infrared light, not the channel region. When the infrared light is incident, the rising and decaying times are 0.1 ms and 45 ms, respectively. The temporal response with the visible light is similar to the previously developed MoS2 phototransistors, however, in the infrared light, the MoS2 phototransistor in this work exhibits very fast operation speed. Furthermore, the Vth shift depending on the incident infrared light can be tunable through the SAL doping on MoS2. According to these advantages, the MoS2 phototransistors with the Ge gate are expected to be used for next generation phototransistor in the optoelectronic platform.
Biography:
Seung-Geun Kim received his B.S. degree in Materials Science and Engineering from Korea University, Seoul, South Korea, in 2016. He is currently pursuing his Ph.D. degree in Department of Semiconductor Systems Engineering from Korea University. His current research interests include optoelectronics and CMOS technology.
1Department of Plant Protection, School of Agriculture, The University of Jordan, Jordan
2Department of Material Science, Royal Scientific Society, Jordan
Green Synthesis approach has been adopted to synthesize magnesium oxide (MgONPs) nanoparticles using Chamaemelum nobile flowers aqueous extract in one-pot reaction. The synthesized magnesium hydroxide and oxide nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The Scanning electron microscopy (SEM) micrographs of synthesized MgONPs showed the smooth surface and random arrangement of MgO nanoflakes with an average thickness of less than 10 nm with an average size of 20–40 nm. Formation of MgO mesoporous structure can be attributed to the presence of C. nobile flowers on the surface of nanoflakes. The highest mortality percent (%) of 1st and 2nd nymphal instars of the grren peach aphid was at 8000 (µg/ml) concentration of MgONPs. It was 86% after 24 hrs, and then reached 88% after 48 and 100% after 72 hours, while mortality increased at 4000 (µg/ml) concentration and reached 86 after 48 hrs and 100% after 72 hrs. The lowest mortality was at using 250 (µg/ml) after 24 hrs then increased to 49 and 88% after 48 and 72 hrs, respectively. The mortalities in case of control were significantly the least after 24, 48 and 72 hrs compared with the other treatments. While the highest mortality% of 3rd and 4th nymphal instars of the green peach was at 8000 (µg/ml) concentration of MgONPs. It was 78% after 24 hrs, and then reached 83, 98% after 48 and 72 hrs, respectively. While mortality at 4000 (µg/ml) concentration and reached 81, 97% after 48 and 72 hrs, respectively. The lowest mortality was at 250 (µg/ml) after 24 hr then increased to 41 and 87% after 48 and 72 hrs, respectively.
Keywords: Green synthesis, Magnesium oxide nanoparticles, Chamaemelum nobile flowers extract, Green peach aphid, Mortality.
Biography:
The presenter Alaa Y. Ghidan, the PhD at The Jordan University, and she has six publications about the same field of nanotechnology, synthesis as an eco-friendly method.
References
Pilarska, A., Wysokowski, M., Markiewicz, E., Jesionowski, T. Synthesis of magnesium hydroxide and its calcinates by a precipitation method with the use of magnesium sulfate and poly (ethylene glycols ). Powder Technology 235 (2013)148-157.
Sierra-Fernandez, A., Gomez –villalba, L.S., Munoz, L, Flores, G., Rafael Fort, R., Rabanal, M.E. Effect of temperature and reaction time of the synthesis of nanocrystallinebrucite. International Journal of modern manufacturing Technology VI (2014)50-54.
Shen, H., Liu, Y., Song, B. Prepaation and characterization of magnesium hydroxed nanoparticles in a novel impinging strem-rotating packed bed reactor. Journal of Chemical Engineering of Japin49(2016)372-378.
Shin, H., YozhiLiu, Y. In situ synthesis of hydrophobic magnesium hydroxide
Yousefi, M. A fast method for synthesis magnesium hydroxide nanoparticles, thermal stable and flame retardant poly vinyl alcohol nanocomposite.Journal of nanostructures 4(2014)383-388.
Baku State University, Azerbaijan
Zinc sulfide (ZnS) is a wide direct band gap, high optical absorption coefficient, reasonable work function. It has attracted considerable attention due to its excellent electrical and optical properties with its distinct properties has become the potential candidate for many applications[1-2].
ZnS layers were electrodeposited from an aqueous electrolyte containing 0.3 M ZnCl2 and 0.03 M (NH4)2S2O3 in 800 mL of de-ionized water. Electropurification of the ZnCl2 was carried out for 48 h prior to the addition of (NH4)2S2O3 in order to remove any possible impurity ions present in the solution. Finally, the pH of the electrolyte containing both precursors was adjusted to 3.00 ± 0.02. The temperature of the electrolyte was 30 °C. Uniform and transparent ZnS layers were cathodically deposited on cleaned glass/İTO substrates using a simple two-electrode deposition system at a cathodic potential of 1550 mV established using a cyclic voltammogram. The deposited layers using an average deposition current density of ~65 µA·cm-2 and deposition time of 60 min have thickness of ~150 nm. These were then annealed in air at 350 °C for 10 min.
Prior to the deposition of Cu2ZnSnS4, the glass/İTO/ZnS substrates were cleaned with methanol and deionised water. The deposition of Cu2ZnSnS4 layers was also done using a two-electrode system at a cathodic deposition potential of 1450 mV also established using a cyclic voltammogram. The Cu2ZnSnS4 deposited on glass/İTO had a thickness ~300 nm while that deposited on glass/İTO/ZnS had a thickness ~150 nm. This therefore brings the total thickness of the ZnS/Cu2ZnSnS4 bi-layer to ~250 nm comparable to the ~300 nm of Cu2ZnSnS4 grown on glass/İTO. The CdTe deposition electrolyte contained 1 M CdSO4 (99.0%) and 1 mM TeO2 (99.999%) in 800 mL of de-ionized water. To do this, a cyclic voltammogram was recorded using the two-electrode system, to determine the reduction potential of Cd2+. The TeO2 was first dissolved in H2SO4 and then added into the bath after the electro-purification of CdSO4, and the pH of the electrolyte adjusted to 2.00 ± 0.02. After depositing and characterizing few CdTe samples on glass/İTO substrates, the final cathodic deposition potential for CdTe was taken as 2038 mV. CdTe thin layers with thickness of ~1.70 µm were then deposited on annealed glass/İTO/CdS and glass/İTO/ZnS/CdS substrates previously cleaned with methanol and de-ionised water. Typical deposition time for the CdTe used in this work was 4 h, with an average deposition current density of ~176 µA·cm-2. To complete the solar cell fabrication, the annealed glass/İTO/Cu2ZnSnS4/p-CdTe 2-layer structure and glass/İTO/n-ZnS/n-Cu2ZnSnS4/p-CdTe 3-layer structure were etched for 5 s in aqueous solution of 1.0 g of K2Cr2O7 acidified with 10 mL of dilute H2SO4 in 10 mL of deionised water, rinsed in deionized water and then etched in a warm solution containing 0.5 g each of NaOH and Na2S2O3 in 50 mL of deionised water for 2 min. The thickness of the gold contacts was ~100 nm each with a diameter of 2 mm. This makes ZnS a suitable candidate for use as effective buffer/window layer in CdTe-based multilayer graded bandgap solar cells. It is important to note what happens to the ZnS/Cu2ZnSnS4/CdTe structure in the annealing process. The glass/ITO/ZnS/Cu2ZnSnS4/CdTe/In solar cell is also similar to the glass/ITO/ZnS/Cu2ZnSnS4/CdTe/In counterpart in structure and is used as a control experiment in this work to compare the advantages of the architecture with ZnS as wide bandgap buffer/window layer. The result of using ZnS as the buffer/window layer is directly reflected in the improved high short-circuit current density (Jsc) as well as improved open-circuit voltage (Voc), fill factor (FF) and ultimately, the conversion efficiency (η) of the 3-layer device, are compared to the device.
However, to ensure that the observed high Jsc values are genuine, the diodes producing them were isolated by carefully removing the CdTe material around them and repeating the I-V measurements. It is therefore possible in these solar cells for photons with energy lower than the energy bandgap of CdTe to create useful electron-hole pairs that contribute to photo-generated current.
Keywords: Solar cells, 3-layer device
References
[1] Razykov, T.M.; Ferekides, C.S.; Morel, D.; Stefanakos, E.; Ullal, H.S.; Upadhyaya, H.M. Solar photovoltaic electricity: Current status and future prospects. Sol. Energy 2011, 85, 1580–1608.
[2] Contreras-Puente, G.; Vigil, O.; Ortega-Lopez, M.; Morales-Acevedo, A.; Vidal, J.;Albor-Aguilera, M.L. New window materials used as heterojunction partners on CdTe solar cells. Energies 2015, 8 4434
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