Day 1 :
Keynote Forum
Ashok Vaseashta
Institute for Advanced Sciences Convergence & Int’l Clean Water Institute
USA
Keynote: Risk Assessment, Safety and Sustainability by Design
Time : 10:00
Biography:
Prof. Vaseashta received a PhD from the Virginia Polytechnic Institute and State University, Blacksburg, VA in 1990. He currently serves as Vice Provost for Research at Molecular Science Research Center at the Claflin University and Strategic Advisor/Fellow at the Institute for Advanced Sciences Convergence and International Clean Water Institute at Norwich University Applied Research Institutes. Previously, he served as a Professor of Physics and Physical Sciences and Director of Research at the Nanomaterials Processing and Characterization Laboratories, Graduate Program in Physical Sciences at Marshall University. Concurrently, he holds/held a visiting/distinguished Professorship at the 3 Nano-SAE Research Centre, University of Bucharest, Romania; Academy of Sciences of Moldova, Chisinau, Moldova; and at the Helen and Martin Kimmel Center of Nanoscale Science at the Weizmann Institute of Science, Israel. In 2007-08, he was detailed as a William C. Foster fellow to the Bureau of International Security and Nonproliferation at the US Department of State working with the Office of Weapons of Mass Destruction and Terrorism and Foreign Consequence Management program.
Abstract:
From a technology standpoint, nanomaterials offer significant advantages due to their unique characteristics resulting from reduced dimensionality. Furthermore, advances in material synthesis have provided the means to control or even manipulate the transitional characteristics. Consequently, various “designer” materials with desired properties have recently been fabricated. Dual-use nature of technology coupled with the ability to functionalize with a plethora of biological configurations pose a significant safety and security concerns. Furthermore, a life cycle analysis of nanomaterials is largely unknown; and nanomaterials resulting from the laboratories, manufacture, and even incidental events pose serious concerns. Notwithstanding such concerns, the beneficial uses of nanomaterials offer a challenging scenario for policy-makers, researchers, and industrialists aliketo propose and implement viable alternatives for sustainable development in terms of keeping up with the latest technological innovations, social responsibility, and“being green”.With so much at stake, it is prudent to challenge conventional wisdom and investigate a new set of strategies that employa nexus of technological innovations, in conjunction with “acceptable” risk assessment and a strategic transformation in “use, reuse, and recycle” as effective management tools to address “design safety, security, and sustainability”. “Sustainability by design”employsstrategic transformations towards ensuring that humans andthe environment can simultaneously flourish on the Earth. Authors have investigated life-cycle-assessment based on the characterization, assessment, and management of risk to assess impacts on human and environmental health from a safety and sustainability standpoint.This presentation offers strategic solutions to a life cycle based approach to nanomaterials and foresight tools, already developed by the authors, to offer possible solutions pathways. The development of a nano-materials safety data sheet (n-MSDS) is being researched by the authors as one such transformation tool needed to provide guidance on the impact of engineered and incidental nanomaterials being introduced and recycled in our supply chain.
Keynote Forum
C D Montemagno
Ingenuity Lab, Canada
Keynote: Thinking small to define a big future
Time : 10:00-10:30
Biography:
Carlo Montemagno, PhD, is the former and founding Dean of the College of Engineering and Applied Science at the University of Cincinnati. Immediately prior, he was the Chair of the Department of Bioengineering and Associate Director of the California Nano Systems Institute as well as the Roy & Carol Doumani Professor of Biomedical Engineering at UCLA. Previous to Montemagno’s tenure with UCLA, he served as Associate Professor in the Department of Biological and Environmental Engineering at Cornell University. He earned his BS in Agricultural and Biological Engineering from Cornell (1980) and MS in Petroleum and Natural Gas Engineering from Penn State University (1990). After completing his undergraduate studies in 1980, he joined the United States Navy and served for ten years in several senior management positions as a Civil Engineering Corps Officer. In 1995, he earned his PhD in Civil Engineering and Geological Sciences from Notre Dame University. He then began his academic career as an Assistant Professor at Cornell University in the Department of Agricultural and Biological Engineering where he was one of the pioneers in the field of Nano-biotechnology.
Abstract:
The ability to use machines to manipulate matter a single molecule at a time renders many things possible that were impossible before. Living systems do this on a regular basis. The core challenge is how to transform a labile molecule that exists in a fragile living organism and to transfer that functionality into a stable system that is economically scalable. The most significant difficulties revolve around environmental stability and the inherent structural limitations of the molecule. Presented is the generic solution methodology used to solve these limiting challenges to produce a new class of materials and devices. Elements of the discussion will include the genetic engineering of active biological molecules into engineering building blocks and their assembly to introduce “metabolism” into engineered devices and materials ultimately synthesizing new classes of materials with advanced functionality that incorporates new intrinsic properties into the matter. Two exemplars will be presented. First we will elucidate the design, engineering and assembly of a complex closed system that uses a highly modified photosynthetic process to transform carbon waste into valuable drop-in specialty chemicals without any living organisms with commercially competitive economics. Secondly, we will present a new technology that stabilizes biological molecules maintaining their function for months at application relevant environmental conditions transitioning additive manufacturing from 3D space to a four-dimensional, functional space. Enabling the synthesis of a new class of printable “inks” that have stabilized and active biological molecules as integrated elements of synthesized polymer constructs to create a new class of materials that now includes biologic function as an intrinsic property. The next wave of technological progress will enable the manufacturing of a unique class of devices and materials that embeds complex functional behavior as an intrinsic property enabling emergent functionality at multiple length scales. These systems will actively interact with their local environment establishing a new capability that will impact solution generation across multiple societal sectors including health care, resource recovery, food production and environmental restoration.
Keynote Forum
Fang Xie
Imperial College London, UK
Keynote: Nanoscale engineering of metal nanostructures for early diagnosis of cancer
Time : 10:30-11:00
Biography:
Fang Xie was awarded her PhD in 2008 and was appointed as a Lecturer at Imperial College London in 2013. She is also Deputy Director for MSc in Advanced Materials in the Department of Materials. She has expertise in metal, semiconducting and oxide nano-materials synthesis and their applications in energy and life sciences. Her current research interests include plasmonic nanostructures for efficient light harvesting for solar cells and solar fuels, as well as in ultrasensitive biosensing and bioimaging applications. She has over 50 publications including 5 patents.
Abstract:
Early diagnosis plays an increasingly significant role in current clinical drive. Detection, identification, and quantification of low abundance biomarker proteins form a promising basis for early clinical diagnosis and offer a range of important medical benefits. Amplification of light from NIR fluorophores by coupling to metal nanostructures, i.e., metal induced fluorescence enhancement (MIFE), represents a promising strategy for dramatically improving the detection and quantification of low abundance biomarker proteins, and potentially increase already sensitive fluorescence based detection by up to three orders of magnitude. The amplification of the fluorescence system is based on interaction of the excited fluorophores with the surface plasmon resonance in metallic nanostructures. The enhanced fluorescence intensity due to the existence of metal nanostructures makes it possible to detect much lower levels of biomarkers tagged with fluorescence molecules either in sensing format or for tissue imaging. The first part of my talk will focus on some recent developments of plasmonic metal nanostructures by both “top-down” and “bottom up” methods. I will then discuss the prepared plasmonic nanostructures in the applications of biosensing.
- Track 1: Nanomaterials and
Track 2: Nanostructures
Chair
Carlo Montemango
Alberta Ingenuity Lab, Canada
Co-Chair
R. M. G. Rajapakse
University of Peradeniya, Sri Lanka
Session Introduction
R M G Rajapakse
University of Peradeniya, Sri Lanka
Title: Low-cost clay-polymer nanocomposites as oxygen reduction catalysts for fuel cell applications
Biography:
R M G Rajapakse holds a BSc special degree in Chemistry from University of Peradeniya and PhD and DIC from Imperial College, London. He is a Senior Professor in Chemistry and is also the Coordinator of the MSc Program in Nano-science and Nanotechnology. He has worked in leading research groups in UK, USA, Germany and Japan and is currently supervising 12 PhD students. He has a large number of publications and 6 patents. He has received 13 awards for excellence in research and is a regular Visiting Professor to Shizuoka University, Japan.
Abstract:
Fuel cells are a kind of galvanic cells with some special features. In fuel cells, reactants are always supplied externally and the anodic half reaction is mandatorily the oxidation half-reaction of a fuel such as hydrogen, methane or any oxidizable fuel, while the cathodic half-reaction is always the reduction half-reaction of oxygen gas. Both reactions are kinetically very slow and hence suitable catalysts are mandatory to drive these reactions with appreciable rates. Reduction of oxygen is catalyzed by Pt and Rh is also used to prevent the poisoning of Pt by by products. This Pt-Rh catalyst is prohibitively expensive and hence alternative low-cost catalysts are required to use fuel cells in power production where fuel cells produce energy in environmentally friendly manner. Numerous researchers have worked on various lines to bring down the cost of oxygen reduction catalysts, which include the use of Pt nanoparticles, or increasing surface area by depositing nano-particulate islands on large surface area supports, alloying platinum with less expensive base metals, developing novel supports or utilizing low-cost materials other than noble metals. In this regards, we have already shown that Ce (III)-polypyrrole (PPY) -montmorillonite (MMT) nanocomposite to be such a very low-cost oxygen reduction catalyst. We now present several other systems which have similar efficiencies for oxygen reduction. These include Fe (II)/PPY/MMT, Ag/PANI (poly-aniline)/MMT, Ag/PANI/MMT, Pd/PPY, PPY/Porphyrins and so on. These materials have been thoroughly characterized by XRD, FT-IR, AC impedance spectroscopy, cyclic voltammetry, etc., and oxygen reduction efficiencies are compared and the results are discussed in this presentation.
Kun’ichi Miyazawa
National Institute for Materials Science, Japan
Title: Synthesis and photo-polymerization of C60 fullerene nano-whiskers
Biography:
Kun’ichi Miyazawa received DE degree from The University of Tokyo in 1987. He was a Lecturer of School of Engineering, The University of Tokyo from 1989 to 2002 and moved to National Institute for Materials Science (NIMS) in 2002. He has been studying the synthesis, characterization and application of low-dimensional fullerene nanomaterials such as fullerene nano-whiskers, fullerene nano-tubes and fullerene nano-sheets.
Abstract:
Fullerene nano-whiskers (FNWs) are thin needle-like crystals with diameters less than 1000 nm, and are composed of fullerene molecules such as C60, C70, Sc3N@C80 and so forth. Among various FNWs, C60 (fullerene) nano-whiskers (C60NWs) have been most minutely investigated in the field of semiconductor devices like field-effect transistors, solar cells, chemical sensors and photo sensors. C60NWs easily become superconductors by doping alkali metals such as K and Rb. The superconducting transition temperature (Tc) of Rb-doped C60NWs is 26 K, which is much higher than the boiling point of hydrogen (20 K). In the future, the Rb-doped C60NWs might be widely utilized as lightweight and flexible super-conductors, using the hydrogen coolant. The FNWs have been normally synthesized by the liquid-liquid interfacial precipitation (LLIP) method. The LLIP method is a very facile technique that utilizes the precipitation and inters diffusion between the good solvent solution of fullerene and its poor solvent.　The as-synthesized C60NWs by LLIP method comprise the C60 molecules weakly bound via Vander Waals bonding forces. However, the C60 molecules can be polymerized by irradiation of light, and the physical and chemical properties of C60NWs can be modified by the light irradiation. In the presentation, the structural characteristics of photo-polymerized C60NWs will be discussed, using high-resolution transmission electron microscopy (HRTEM), EELS and Raman spectroscopy.
Biography:
Masakazu Iwamoto has completed his PhD from Kyushu University, Japan and Post-doctoral study from Texas A&M University. He was an Associate Professor at Nagasaki University, and Professor at Miyazaki University, Hokkaido University and Tokyo Institute of Technology. He has published more than 300 papers, was an Editor-in-chief of Applied Catalysis B and Environmental and works for Chuo University as an Institute Professor.
Abstract:
The wall ion-exchange (WIE) method, in which wall anions in composites of zirconium sulfate and surfactant micelles (ZS) were exchanged for oxyanions in aqueous solutions, was applied to prepare mesoporous tungsten-zirconium composite oxide (WZO). The amounts of tungsten introduced into the ZS structure (Win) were very small at pH=2-5 and greatly increased at pH=5.6 and above. In the exchange at pH=5.6-10, the ratios of tungsten introduced and sulfur removed were 0.9-1.1, indicating the stoichiometric ion-exchange. This would result from the difference of predominant tungsten oxyanions in the solutions, W12O396- (the diameter, 0.7 nm) at the low pH and WO42- (0.27 nm) at high pH, since the diameter of the latter is very similar to that of the HSO4- ion (0.21 nm) in ZS, resulting in the easy WIE reaction. The relationships among the amount of Win, the removal method of the surfactants, the surface area and the pore diameter of WZOs were systematically studied and WZO samples with high surface areas of 200-520 m2g-1 and pore diameters of 0.8-2.4 nm could be prepared. The catalytic activity of the resulting WZO for the Friedel-Crafts alkylation was strongly dependent on the removal method of the surfactants and the W/Zr ratio. The WZO samples prepared with calcination or extraction showed low activity for the catalysis, while the extracted and then calcined WZOs with W/Zr>0.45 were specifically active. The activity was well proportional to the amount of mono-dentate W species produced in the pore surface of the WZO samples.
Biography:
Kristina Lilova has completed her PhD from University Henri Poincaré – Nancy 1, France (currently University of Lorraine) and Post-doctoral studies from Unversity of California, Davis. She is currently an Applications Manager at Setaram Inc. She has published 24 papers and book chapters in reputed journals and has been serving as an Associated Editor of American Mineralogist and Frontiers in Energy Research journals.
Abstract:
Graphene, single-walled (SWCNTs) and multi-walled nanotubes (MWCNTs), onion-like carbons (OLCs) and nanodiamonds are attractive materials due to their two-dimensional structure, unique properties and potential applications in many fields as electronics, catalysts, photonics, robotics, mechanics, energy storage and orthopedics. All those new developments require a thorough study of the mechanical, physical and chemical properties of the nanocarbons and the corresponding composites. The density and the thermal expansion coefficients of CNTs-containing composites can be investigated using thermomechanical techniques. Thermogravimetry combined with differential scanning calorimetry (TG-DSC), is a powerful method to determine the amount of the impurities, the effect of the thermal treatment and the thermal stability of CNTs and graphene composites. The isothermal immersion and oxidative calorimetry are commonly used to study the surface properties and thermodynamic stability of CNTs and OLCs, which are critical for their applications as catalysts and energy storage materials. These techniques will be introduced and illustrated by several examples on 2D nanomaterials.
Muzafar A Kanjwal
Technical University of Denmark, Denmark
Title: Smart TiO2 and TiO2-Ag based materials for high flux and photocatalytic degradation of dairy effluent
Biography:
Muzafar A Kanjwal has completed his PhD from Chonbuk National University, South Korea. Currently, he is working as Researcher at National Food Institute, Technical University of Denmark. He has published more than 40 papers in reputed journals. His research focuses on photocatalysis, and developing nano/micro structures by electro-spinning method.`
Abstract:
Special importance is given to highlight new techniques and recent progress in enhancing photo catalytic efficiency and flux of TiO2-based materials, which drives the design of key strategies and potential new directions of TiO2 photo-catalysts. The TiO2 and TiO2-Ag nanofibers were produced by electro-spinning technique. Silicone elastomer discs (diameter: 10.0 mm; thickness: 2.0 mm) are surface coated with the TiO2 and TiO2-Ag nanofibers. The surface functionalization of these nanofibers on silicone elastomer surface by dip-coating method, results in the formation of (TiO2-) and (TiO2-Ag) silicone discs. The coated discs were characterized by various techniques like SEM, TEM, XRD, FTIR, EDS, UV, etc. These characterizations reveal that surface morphology of electrospun nanofibers has not been lost by the dip-coating technique. The produced material TiO2- and TiO2-Ag silicone discs, when utilized as photo-catalysts to degrade water (dairy waste in this study) exhibited good results, and very good material for high water flux and water photo-splitting.
Zhao Li
National Research Council Canada, Canada
Title: Semiconducting SWCNT: From materials to thin film transistors
Biography:
Zhao Li has completed his PhD in 2000 from Chinese Academy of Sciences and then pursued his 3 years Postdoctoral studies in Calgary University in Canada. He has joined Canadian Research Council in 2003 and presently he is a Research Council Officer. His research is focused on conjugated polymer synthesis and characterization, organic photovoltaics, carbon nanomaterials and its application in thin film transistors. He has published more than 35 papers in reputed journals.
Abstract:
Significant progress has been made in the last ten years on the topic of separating semiconducting (SC) from metallic single walled carbon nanotubes (SWCNTs). Techniques such as conjugated polymer extraction (CPE), chromatography and density gradient ultracentrifugation (DGU) have been shown to be particularly effective at SC-SWCNT enrichment. As a result, the fabrication of thin film transistors comprising enriched SC-SWCNTs has been undertaken by several research teams in hopes of obtaining higher performance printed logic, display drivers and novel sensors. We have compared DGU, chromatography and CPE and found the later to have many positive attributes such as a competitive cost model, scalability and product quality. Our recent progress and commercialization (IsoSol-S100TM) of the CPE method to produce high purity SC-SWCNTs dispersed in organic solvents will be presented. We also developed a novel methods using Raman mapping to quantify SC-SWCNT purity beyond 99%. After fine-tuning the substrate surfaces and SWCNT/polymer solution property, uniform and high density tube network was obtained. Thin film transistor (TFT) based on SC-SWCNT as active channels demonstrate both high mobility and on/off ratio. Application of this kind of solution as ink for inkjet printing will also be addressed.
Etakula Nagabhushan
Osmania University, India
Title: Synthesis and characterization of strontium zinc oxide nano-composite via soft chemical process
Biography:
Etakula Nagabhushan has completed his PhD from Osmania University. He completed his B-Tech in Chemical Engineering and M-Tech in Ceramic Engineering from Osmania University, India. He has guided about 30 M-Tech theses. He has 25 years of teaching and research experience. Presently, he is the Professor and Head, Dept. of Ceramic Engineering & Materials Science Technology, Osmania University. His areas of interest are ceramics, polymers and nano-materials.
Abstract:
Nanostructured materials provide many benefits due to their enhanced properties, the promising applications of nanostructured materials have generated innovative method to synthesis new materials with high performance to enhance their use as Nano devices, Nano catalysts and Nano sensors. Although the use of Nano materials in industry is limited, their use in industry has already started and is expected to be extensive in the next few years. In the present study Strontium Zinc Oxide (SrZnO2) Nanocomposite was synthesized by soft chemical approach by using Strontium Oxide with Zinc Oxide. Soft chemical approach helps for the synthesis of colloidal dispersion organic and inorganic materials at relatively low temperatures and with simple set up. The synthesis was carried out at moderate temperature 90ËšC and then finally dried in the laboratory oven at 100 ÌŠC for 24 hours and then followed by calcination at 1000 ÌŠC in a furnace with the heating rate of 5 ÌŠC/min for 6 hours to get a phase selective product. The concept of Soft chemical approach depends on the balanced synthesis-structural relationship based on electro negativity. The structure, morphology and properties of the particles were characterized by XRD, SEM and FT-IR. The mean particle size was calculated by using X-ray diffraction pattern by using Scherer’s Equation, t=0.9λ/ B CosѲ. The results obtained from different characterization techniques showed that nanostructured materials where formed with small sizes of particles, with good crystallinity and clean environment which can be used for appropriate technologies like Nano devices, Nano catalysts, Nano sensors, etc……
Yongmei Zheng
Beihang University, China
Title: Bioinspired surfaces with gradient micro- and nanostructures to control wettability
Biography:
Yongmei Zheng is currently a Professor at School of Chemistry and Environment, Beihang University, China. She received her PhD (2003) from Jilin University, China. She firstly worked at Department of Applied Physics in Jilin University of Technology (1987) and then as a Post-doctoral fellow in ICCAS (2003) and as a Researcher at Centre for National Nanoscience and Technology (2005). Her research interests are focused on dynamic wetting-controlled functions of bioinspired surface materials. Her publications are included in Nature, Adv. Mater., and Angew. Chem. Int. Ed., ACS Nano, etc. She is a member of American Chemical Society (ACS), Chinese Chemical Society (CCS), etc.
Abstract:
Biological surfaces with unique wettability endow us knowledge. Since spider silk collects water in mist, taking on scene of large pearly droplets, we have revealed the mechanism of the cooperation between surface energy gradient and difference of Laplace pressure. Recently series of bioinspired fibers have been designed by the developing novel techniques at micro- and nano-level. Thus these bioinspired fibers take on unique abilities such as the capturing of extreme hanging-drop; the directional driving of tiny condensed droplets on photo or temperature responsive spindle-knots and joint; the heterostructured bead-on-string fiber for humidity response; the controlling of condensed droplets in directional transport in long range gradient spindle-knots. Learned from water repellency of butterfly wing and plant leaf, bioinspired surfaces are designed to display anti-icing, ice-phobic and de-ice abilities. The oriented or asymmetric features on geometries at micro- and nano-level can generate the driving of droplets that is resulted from the surface energy gradient, in addition to the trapped-air in multi-structures at Cassie’s state. These bioinspired surfaces with micro-/nanostructures would be promising applications into wetting-controlling, water collection and ice-phobic/anti-icing.
Naoto Saito
Shinshu University, Japan
Title: Carbon nano-tube toxicity: In-situ imaging method using peapods to evaluate the bio-kinetics of carbon nano-tubes
Biography:
Naoto Saito is a Professor and Director of the Institute for Biomedical Sciences, Shinshu University. He is an experienced researcher specializing in biochemistry, cell biology, regenerative medicine, biomaterials and nano-biotechnology. As the leader of Shinshu University’s Nano-biotechnology and Biomedical Engineering Team, he is working on developing CNT-based biomaterials.
Abstract:
The bio-safety of carbon nano-tubes (CNTs) is a concern, and CNT bio-kinetics is a key bio-safety issue. CNTs labelled with carbon isotopes, functionalized with moieties, or coated with colloidal metal particles have been used to monitor CNT bio-kinetics, though major technical issues (such as isotope preparation and handling or change in CNT surface properties) remain. The present report aims at establishing an advanced and simple in-situ imaging method of CNTs monitoring in vivo involving the use of CNTs filled with heavy metal particles (peapods). Gd-peapods containing GdCl3 were synthesized using double-walled CNTs. The limits of Gd-peapods detection on MRI in solutions and agarose gel cubes were 1.3µg/ml and 4µg/ml, respectively. The peapods in rats was easily visualized by MRI and the change in signal intensity was dose-dependent. This newly developed method can be used to monitor CNT bio-kinetics in vivo without tedious tissue preparation.
Toshihiro Moriga
Tokushima University, Japan
Title: Control of optical properties of oxynitride pigments through stoichiometries
Biography:
Toshihiro Moriga graduated from Department of Chemistry, Osaka University in 1988 and received his Doctor of Science from Osaka University in 1996. He is now a Professor of Department of Advanced Materials, Institute of Technology and Science, Tokushima University, Vice-dean of Faculty of Engineering of the University and Director of Center for International Cooperation in Engineering Education of the Faculty. He has published more than 130 papers in peer-reviewed journals and an organizer of the special session, “Advanced structure science and pioneering novel materials” in fall meetings of the Ceramic Society of Japan since 2007.
Abstract:
We have demonstrated that a color of the perovskite-type LaTiO2N oxynitride could be tuned from orange through yellow and green to white by proper adjustment of O/N and Ti/La ratios. However, we have not obtained real red oxynitrides in this system yet. LaTaON2, which contains more nitrogen amount than LaTiO2N, can be expected as the redder pigment. However, the ionic size of La3+ seems to be so small for accommodating the ideal perovskite that the crystal structure may be deformed to be monoclinic system. Distortions to bond angle of Ta-(O,N)-Ta were reported to make the bandgap wider. In this study, we prepared solid solutions of La1-xBaxTa(O,N)3 and the compositional variation of optical properties as well as structural ones were examined. We also studied effects of addition of NaCl flux during nitridation on the color due to particle size distributions. Perovskite-type La1-xBaxTa(O,N)3 oxynitrides showed slight redshift of absorption edge and deteriorated reflectivity in the longer wavelength regions after absorption edge with increasing Ba content x due to relaxing Ta-(O,N)-Ta distortion. Addition of NaCl flux in the oxide precursor of La1-xBaxTa(O,N)3 during the nitridation led to improvement of the reflectivity after absorption edge without changing the anion ratio. LaNbON2 should be one of the redder pigments. Substitution of titanium by niobium in LaTiO2N would enhance covalency in bonding between the cations and anions because electronegativity of niobium is slightly larger than that of titanium. We also examined anion composition and optical properties of solid-solution of LaTi1-xNbx(O,N)3 and will discuss difference in ways of variation of optical properties against the substitutions mentioned above. Perovskite-type LaTi1-xNbx(O,N)3 oxynitrides showed redshift of the absorption edge due to enhancement of covalent character and increased absorption in red region due to anion defects, with increasing Nb content x. The absorption would possibly affect the gradient of reflectivity curve after the absorption edge to assist to show the redder color. The oxynitride solid-solutions with x=0.2 and 0.3 possessed the color coordinate same as that of red iron oxide.
- Young Researchers Forum
Session Introduction
Jianhe Guo
Materials Science and Engineering Program
USA
Title: Ultra-durable rotary nanomotors assembled from nanoentities by electric fields
Biography:
Jianhe Guo is a third year PhD student in the Materials Science and Engineering Program at The University of Texas at Austin (UT Austin). He received his bachelor's degree in materials chemistry from The University of Science and Technology of China (USTC) in 2012. He has been nominated for the “2015 HHMI International Student Research Fellowship”,received“2014 Harris L. Marcus Graduate Fellowship” in Materials Science &Engineering and “2014 Graduate Student Professional Development Award” by UT Austin. Working as a research assistant in Prof. Donglei (Emma) Fan’s group, he focuses his research on innovative design, manufacturing, and applications of micro/nanoelectromechanical (MEMS/NEMS) devices such as nanomotors, and also synthesis and applications of novel carbon materials including graphene and graphite foam
Abstract:
Recently, we reported an innovative type of nanomotors consisting of nanowires as rotors and patterned Au/Ni/Cr nanodisks as bearings. The dimensions of nanomotors were less than 1 µm, and could continuously rotate for 15 hours over 240,000 cycles. To understand the limitation of their lifetime, we systematically investigated the rotation dynamics by analytical modeling and determined the time-dependent torques and forces involved in the rotation. From the forces and torques, the extent of wear of nanomotors was successfully derived, which well agreed with the experimental characterizations. The results also proved that frictional force linearly increases with the loading in such rotary nanodevices operating in suspension, consistent with the predictionof the non-adhesive multi-asperityfriction theory. With these understandings, we enhanced the design of nanomotors and achievedan operation lifetime of 80 hours and over 1.1 million total rotation cycles. This research, shining new light on the frictional mechanism of recently reported nanowire nanomotor with demonstration of the most durable rotary nanomechanical devices of similar dimensions to the best of our knowledge, could be inspiring for innovative design of future nanomechanical devices with ultralong lifetime for practical applications.
Feven Mattews Michael
University of Nottingham Malaysia Campus, Malaysia
Title: PLA/GNP/NHA: Application of poly-lactic acid reinforced with graphene nano-platelets and nano-hydroxy apatite hybrids in load bearing bone implants
Biography:
Feven Mattews Michael is currently a PhD research student in Department of Chemical Engineering under Manufacturing and Industrial Processes Division at Nottingham University Malaysia Campus. Her research interests include tissue engineering, polymer nano-composites and nano-composites modified with radiation.
Abstract:
The interaction of the materials used to design the scaffold with the biological tissues plays a vital role. Currently, biomaterials such as synthetic polymers i.e., poly-lactic acid (PLA) are actively investigated in bone tissue engineering due to their biocompatible, bio-resorbable and biodegradable nature. Furthermore, nano-hydroxyapatite (NHA) a bio-ceramic material that happens to be the major constituent of the inorganic segment of the bone has also attracted much attention due to its excellent biocompatible nature. In this study, 10-30wt% of NHA synthesized through precipitation method was used to reinforce PLA matrix via melt-mixing. With addition of 30 wt% of NHA, the thermal stability of the composite was seen to improve by 4%. However, PLA and NHA possess poor mechanical properties, limiting their application for load bearing bone implant. As a result, 0.01 g of graphene nano-platelets (GNP) dispersed in acetone was mixed with the synthesized NHA with the aid of ultra-sonication. The GNP/NHA hybrid was then used to reinforce the PLA through melt-mixing. From the field emission scanning electron microscopy (FESEM) images obtained, homogenous dispersion of GNP/NHA in the PLA matrix was observed. This in turn contributed to the increase in mechanical properties of the composite with addition of 30 wt% GNP/NHA by 11% and 9% compared to pure PLA and PLA/NHA composites.
M Shaat
New Mexico State University, USA
Title: On the mechanics of nanomaterials in micro-/nano-scale applications
Biography:
M Shaat is a PhD student in the Department of Mechanical and Aerospace Engineering at New Mexico State University under the supervision of Prof. Abdessattar Abdelkefi. He earned his Master of Science in Mechanical Engineering from Zagazig University, Egypt. His main research interests are in the fields of mechanics of nanomaterials, mechanics of micro-/nano-solids, MEMS and NEMS, nanocomposites, and functionally grade materials. He has published more than sixteen papers in international journals, such as International Journal of Mechanical Sciences, Microsystem Technology, and International Journal of Engineering Science. He has served as a reviewer in more than seven international journals.
Abstract:
Unlike the conventional materials, the properties of nanomaterials are highlighly affected with their material structure. For example, the mechanical properties of nanocrystalline materials are highly affected with the heterogeneity nature of their material structure and the grains size. In addition, the properties of single crystal solids are directly related to their atomic structure and their dispersive behaviors. In this presentation, two approaches are presented to accurately model micro/nano-solids made of nanomaterials. In the first approach, a general nonlocal continuum theory is proposed to model micro-/nano-solids made of single crystalline nanomaterials. This general theory has the merit to model the residuals of the nonlocal fields that may exist inside the crystal structure. Three types of nonlocal fields are discussed and modeled in the context of this general theory. In the first and second types, the interatomic forces are extended over the whole crystal. These forces are electromagnetic forces that produce acoustic and external optical phonons inside the crystal with long-range effects. In the third type, the interatomic forces are only effective within the interatomic distance range. These forces are the main reason behind the nonlocal internal optical phonons of unit cells. To investigate these nonlocal fields inside the crystal structure, the crystal is modeled as a continuum consisting of repeated unit cells and each unit cell is modeled as a deformable micro-body. In the second approach, a nonclassical continuum model is integrated with a size-dependent micromechanical model. The micromechanical model has the merit to estimate the properties of the material considering the grain size effects and accounting for the grain boundaries, the triple junctions, the quadratic nodes, and porosities inside the material structure. Then, one of the nonclassical continuum theories is utilized to model grains as volume elements capturing the discrete nature of their atomic structures.