King Abdullah University of Science and Technology, Saudi Arabia
Substrate effects on silicene and how to exploit them
Udo Schwingenschlögl is a Professor of Materials Science & Engineering at King Abdullah University of Science and Technology (KAUST), Saudi Arabia. He previously worked at the International Center of Condensed Matter Physics in Brasilia, Brazil, and the University of Augsburg, Germany. His research interests in condensed matter physics and first-principles materials modeling focus on 2D materials, interface and defect physics, correlated materials, thermoelectric materials, metal-ion batteries, nanoparticles, and quantum transport.
Silicene is the Si analogue of graphene with the same honeycomb structure and linear dispersions of the π and π* bands at the K point of the Brillouin zone. It is predicted to realize a buckled structure, due to sp2-sp3 hybridization, and is compatible with the current Si-based nano-electronics. Silicene yet has not been achieved by mechanical exfoliation but can be deposited on metallic substrates such as Ag(111), Ir(111), and ZrB2(0001). Regrettably, strong interaction to these substrates destroys the Dirac physics. For this reason, semiconducting substrates, including Si(111) and SiC(0001), have been explored theoretically to evaluate whether they lead to a Dirac cone with reasonable band gap (which is essential for applications). However, surface passivation is inevitable for these and similar substrates, due to their dangling bonds. Layered materials such as MgBr2(0001), MoX2, and GaX2 (X = S, Se, and Te), on the other hand, might preserve the characteristic electronic states of silicene and additionally simplify the preparation procedure as passivation is not required. The predicted effects of different substrates on silicene will be compared and evaluated with respect to technological requirements.
College of Engineering and Computer Science, USA
Structure Formation in High Performance Fibers with Polymer Blends and Nanotubes for Extreme Loading
Dr. Hassan Mahfuz is the Director of Nanocomposites Laboratory and Associate Dean for Research, College of Engineering and Computer Science. His research interests are Computational Methods in Solid Mechanics, Finite Element Method, Polymers, Polymer Composites, Polymeric Fibers, Composites Manufacturing, Mechanics of Composites, Nanomaterials, Nanocomposites, Experimental Stress Analysis, Machine Design, and Computer Aided Design.
Fibers like M5, PBO, Spectra, and Kevlar are used in high impact applications. Although these fibers have high strength and modulus, their fracture strain is low which leads to moderate energy absorption. Normalized velocity for M5, PBO, Spectra, and Kevlar are currently at 1000, 837, 887, and 680 m/sec, respectively. Normalized velocity is a combined measure of fiber’s toughness and tensile wave speed, which is essentially the total energy absorption by the fiber. The question is – whether this energy absorption can be doubled or tripled for extreme loading events. Such high energy absorption is possible through a transformative change in the structure of the fiber. It has been shown that such structural change can be made through a hybridized polymer blend and infusion of carbon nanotubes.
A case in point is ultrahigh molecular weight polyethylene (UHMWPE) and nylon. Fracture strain of nylon is one order higher than that of UHMWPE while its strength and modulus are one order lower. Blending of the two increases fracture strain of UHMWPE to an intermediate level. On the other hand, dispersed nanotubes get aligned during the drawing process, co-continuously deformand carry the load resulting in higher strength and modulus. Net effect therefore leads to higher energy absorption. From a quantum energy concept, both polyethylene and polyamideshave small cluster of atoms, allowing an opportunity to exchange molecular features if blended. Polymer (blended) crystallinity, strength, and modulus otherwise lost in the blending process, can be fully recovered and enhanced further with the inclusion of nanotubes.The presentation will delve into scientific inquiries to understandinterplay at the interface of major and minor phases, role of compatibilizer, deformation of the dispersed phase, formation of chemical bridges, interfacial tension, and role of nanotubes in sharing load and developing crystallinity.
Investigating the Effects of Electrical Stimulation via Gold Nanoparticles on In Vitro Neurite Outgr
Moein Adel has his expertise in nerve regeneration and nanotechnology. His open and contextual evaluation model creates new combination and optimization pathways for treatment of CNS damages. He has built this model after years of experience in research, evaluation and teaching both in research and education institutions. The foundation is based on fourth generation evaluation (Guba& Lincoln, 1989) which is a methodology that utilizes the previous generations of evaluation: measurement, description and judgment. It allows for value-pluralism. This approach is responsive to all stakeholders and has a different way offocusing.
Statement of the Problem:Following the injury of nervous tissue, in particular, spinal cord injuries, axons do not regenerate appreciably in their native environment and current clinical approach to treating damaged nerves is inefficient; thus, medical treatment approaches are needed. Neural tissue engineering research field has been progressed by using different approaches especially for repairing of damaged neural cells. In addition, it is known that electrical stimulation can be used for neurite growth and nerve regeneration.
Methodology & Theoretical OrientationIn this study conductive properties of gold nanoparticles (GNPs, 39 nm) and their contribution to the enhancement of electrical stimulation to nerve cells have been conducted. In experimental section, polyethyleneimine (PEI) polymer coated cover glasses was used to create a positively charged glass surface and adsorption of GNPs was used in conjugation with this polymer coated substrate. Subsequently, PC12 cells were cultured on the modified glass surface and pulsed electric field of 1.5 V, 20 Hz was applied as electrical stimulation for 55 min duration.
Findings: Images from FESEM showed a uniform distribution of GNPs on glasses surface. In addition, enhanced neurite outgrowth (120 μm) using electrical stimulation was determined by inverted phase contrast microscopy images.
Conclusion & Significance: Finally, our study showed that pulsed current stimulation induced neurite outgrowth of PC12 cells adhered to the GNPs coated surfaces. Altogether, synergist combination of GNPs together with pulsed electrical stimulation can be used for enhanced nerve regeneration. Our future works will direct towards optimizing properties of NPs and stimulation parameters for in vivo nerve regeneration and do a comparative study with other nanomaterial including silk, carbon materials and etc.
Manipal University, India
Influence of Thermal Processing Rate on the Structural and Morphological Properties of Cu2SnS3(CTS)
The copper tin sulfideCu2SnS3 (CTS) is a p-type direct band gap material; its elements are non-toxic and earth-abundant. It can be used in photo thermal conversion of solar energyand as selective radiation filters on architectural windows. The CTS compound was synthesized by solid state reaction method. The influence of soaking time on the structural and morphological properties ofthese films are investigated. X-Ray diffraction analysis of these compounds prepared with varying thesoaking time at 9000C are found to exhibit tetragonal CTS phase with preferred orientation (1 1 2), (2 2 0) and (3 1 2).The XRD pattern showed that prepared samples do not contain any secondary phases.The grain size calculated using Debye-Scherer’s formula was found to be in the range of 34nm-46nm. The chemical composition of the compound estimated using Energy dispersive spectroscopy showed Cu/Sn atomic ratio in the range 0.9 to 1.10.
Ashwatha Narayana Prabhu
Manipal University, India
Synthesis, Growth and Characterization of Acetophenone-4-Quinoline-D Chalcone Single Crystal: A Pote
The new potentially useful nonlinear optical (NLO) organic material Acetophenone-4-quinoline-D chalcone has been synthesized using claisen-schmidt condensation reaction method and single crystals were grown by slow evaporation solution growth technique. Powder x-ray diffraction (XRD) study was carried out to determine the structure of the compound. It was observed that the crystallite size varies from 10-10 to 10-9 with increase in angle, it may be due to compressive strain developed in the crystal. It has been observed that dislocation density, micro strain and distortion parameter changes randomly due to mismatch in the atoms or ions.The thermal stability of the compound was determined using differential scanning calorimetry (DSC) method. It was found that melting point of the crystal is found to be 150.4 °C. The UV-Visible absorption study of the crystal was carried out using UV-Visible spectrophotometer over the spectral range 300-1200 nm at room temperature. It was observed that the sample has good transparency window in the entire visible and near IR region. The second harmonic generation (SHG) efficiency of the crystal was recorded using powder technique using Nd: YAG laser and is found to be 1.5 times that of reference sample urea of identical particle size.
Ahmed EL Hichou
Université Cadi Ayyad, Morocco
Electrodeposition of Li- doped ZnO Nanowire arrays for Solar cell
Ahmed El Hichou is a Materials Physicist. He is an Assistant Professor in department of Applied Physics at Université Cadi Ayyad.
Undoped and lithium doped zinc oxide thin films were deposited by electrodeposition technique from aqueous solution onto ITO substrates at optimum conditions. The variations of the structural, electrical and optical properties with the doping concentration were investigated. XRD analysis showed typical patterns of the hexagonal ZnOstructure for both doped and undoped films. The films were polycrystalline with the (002) preferred orientation. No diffraction peaks of any other structure were found. The grain size and optical band gap were evaluated for different doping concentrations. The films with 5.10-6 M Lithium had a high crystallographic quality and a resistivity of 3,9.10-4 ?.cm with an energy band gap of 3,3 eV.
It is very obvious that ZnO-Li films fabricated by sol-gel at optimum conditions are suitable for electronic applications, especially those requiring transparent electrodes.
Atomic Energy Commission of Syria, Syrian Arab Republic
Metal organic framework for Radioactive Nuclides capture and storage
Dr. Bassem join Highest Institute For Applied Science and Technology (HIAST) in the Department of physics. He received diploma from HIASTin the field of Nuclear Engineering in 2002 .He received a Master’s degree in Applied physics from Delft university of Technology in the Netherlands in 2006. and Ph.D. from Technical university of Dresden in Germany in 2011. In his thesis, he focused on Hydrogen storage in Nano-structured materials. His research focused on creating nano materials to pull radioactive ions from nuclear waste.
Screened a diverse set of 12 metal-organic frameworks (MOFs) for iodine capture using a molecular modelling. The simulation results provide insights into the influence of pore volume and surface area that influence the storage capacity. We have shown that MOFs with high pore volume and surface area preferred for iodine storage at ambient conditions of pressure and temperature, while at low pressure MOFs with smaller pore volume are more qualified for iodine capture. Moreover, some materials show very high adsorption capacity at normal conditions (13 g g−1), which is higher than any material capacity reported to date. Simulations also show that adsorption sites formed by the metal clusters are the preferential adsorption
sites for iodine molecules. In order to increase the iodine capacity of MOF type materials, structures with high density of metal sites must be designed. One MOFs (Cr-MIL-101) was prepared and investigated in detail to demonstrate the iodine removal efficiency and capacity of MOFs. Detailed material characterization analysis is presented for the MIL-101 loaded with I2. This includes powder X-ray diffraction (XRD), Infrared (IR), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS).
The typical sorption kinetics and uptake isotherms were measured using radioactive iodine (123 I) for the first time. The results showed that MIL-101 has the same efficacy for capture of radioiodine 123I (96.61%) in comparing with active carbon (98%) but with much faster kinetics. Our results demonstrated that MOF scan be use as agent for radioiodine capture in hot cells and for nuclear accidents with radio iodine.
A. Moghaddam Jafari
Islamic Azad University, Iran
Synthesis and Characterization of Gold-Preyssler-Titanium dioxide Nanocomposite
Afsaneh Moghaddam Jafari got bachelor of Applied chemistry from Ferdowsi University of Mashhad and my master degree of inorganic chemistry from Azad university of Mashhad . She could achieve the highest GPA (3.9/4) among 60 graduate students of Inorganic chemistry program . She worked at the water and sewer company of Mashhad as an researcher in 2010 after that she was research assistant in department of chemistry in Azad university of Mashhad during her study of master from 2011 to 2013 . Her primary research interests are in the field of inorganic chemistry and Nanotechnology . Specifically, she is interested in produce metal Nano particles and their application in drug delivery, Nano photo catalysis and semiconductors and their application in medicine and environment .
Investigations on the photocatalytic application of TiO2 and its composite materials are intriguing interest, due to the small crystal size, high specific surface area and highly porous structure of mesoporous titanium dioxide [1, 2]. However, the most drawbacks of TiO2 are its large band gap and massive recombination of photogenerated charge carriers, which make the catalytic efficiency low. Thus, modification of the electronic band structure of TiO2 by noble metal deposition and co-doping with two or more foreign ions have been attracted much attention to overcome the large band gap of TiO2 . In this research, demonstrated a facile co-doping approach to synthesize of gold-Preyssler-titanium dioxide nanocomposite, as a new and green photocatalyst. Synthesized this nanocomposite and characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In addition, the photo degradation of Malachite Green as an pollutant azo dye, in a designed photo reactor in our laboratory was performed as a test reaction to estimate the catalytic activity of this nanocomposite. The obtained results showed that malachite green solution can be degraded under UV light in the presence of the synthesized nanocomposite. For a systematic comparison, the photocatalytic activity was performed with classical catalyst: TiO2. In all cases, maximum of photodegradation was observed by using gold-Preyssler-titanium dioxide nanocomposite as catalyst. The remarkable degradation of malachite green in the presence of this nano catalyst indicates that the treatments of other organic pollutants could be performed in the presence of this catalyst, in order to obtain a perfect photodegradation degree. This catalytic activity can also be extended to the other catalytic reactions.
Kemal Can Demirkilinc
Anadolu University, Turkey
Poster: A New Microemulsion Formulation for an Oil-Soluble Drug
The aim of this study was to design and develop a microemulsion drug delivery system for an oil-soluble drug, TGF-b. Microemulsions are transparent, thermodynamically stable and isotropic fluid mixtures of oil, water and surfactant, frequently in combination with a co-surfactant. In contrast to emulsions, microemulsions form upon simple mixing of the components and generally do not require high shear conditions used for emulsion formation. In this study, microemulsion systems were prepared using different surfactant, co-surfactant and oil ingredients. Among the ingredients tested were Tween® 20 and Tween® 80 as surfactants, PEG 400, glycerole, 2-propranol and isopropyl alcohol as co-surfactants and soybean and linseed oils. Microemulsions were prepared using pseudo-ternary phase diagrams. Optimum formulation was selected and characterized by droplet size, electrical conductivity, zeta potential and pH measurements.