4th International Conference on
Materials Science & Engineering
Scientific Program
Keynote Session:
Title: Experiment studies in abrasive waterjet cutting of materials
Biography:
Chithirai Pon Selvan obtained his Bachelors in Production Engineering, Masters in Computer Aided Design and PhD in Mechanical Engineering. Chithirai Pon Selvan has over twenty years of experience in teaching, educational assessment, classroom management and student relations. He has published 100+ research articles in International journals and conferences. He has been invited and honored as keynote speaker, session chair, resource person and technical committee member in various conferences in UAE, India, Thailand, Malaysia, UK, Germany & Italy. He is in the editorial board of more than 50 International journals. His research interests are in the areas of machine design, optimization techniques and manufacturing practices, particularly non-traditional manufacturing methods.
Abstract:
Abrasive waterjet cutting is one of the unconventional machining processes capable of cutting wide range of difficult-to-cut materials. This process incurs comparatively higher initial investment, maintenance and operating costs. Therefore optimum choice of the process parameters is essential for the economic, efficient and effective utilization of this process. This paper assesses the influence of process parameters on depth of cut and surface roughness which are the important cutting performance measures in abrasive waterjet cutting of materials. Experiments were conducted by varying water pressure, nozzle traverse speed, abrasive mass flow rate and standoff distance for cutting materials using abrasive waterjet cutting process. The effects of these parameters on depth of cut and surface roughness have been studied based on the experimental results. In order to correctly select the process parameters, empirical models for the prediction of depth of cut in abrasive waterjet cutting of materials is developed using dimensional analysis technique. These developed models have been verified with the experimental results that reveal a high applicability of the models within the experimental range used.
Title: Multiphysics sintering modeling, a necessary tool for advanced sintering processes and material properties optimization
Biography:
Charles Maniere has completed his PhD at the age of 28 years from the Univerty of Toulouse on the modeling of Spark Plasma Sintering; from 2016 to 2018 he has completed a 2 years PostDoc at the San Diego State University with Prof Eugene Olevsky who is the co-founder of the “continuum theory of sintering” He used during his PhD. During this PostDoc, Charles develops advanced multiphysics models for microwaves sintering and flash sintering, and additive manufacturing. In 2018, he has succeeded the selective entry of CNRS and starts his new CNRS assistant scientist position (chargé de recherche) at the laboratory CRISMAT from CAEN (France) where he is developing his activity on sintering.
Abstract:
The success and new developments of technologies such as additive manufacturing, 3D printing has considerably increased the interest of the sintering process which has become a key step for material properties optimization. On the other hand, the sintering via advanced processes such as Spark Plasma Sintering (SPS) or microwave sintering obey complex Multiphysics phenomena such as resonance, electro-thermal contact resistance, surface to surface thermal radiation, convection and the complex interaction between all these phenomena and the temperature dependent properties.First presentation the Electro(magnetic)-Thermal-Mechanical (ETM) model we develop to assess the highly complex nature of advanced sintering processes like SPS and microwave sintering1. Then, a focus will be bone on the modeling of the densification/grain growth interaction for obtaining advanced nano-grains ceramics. In the second part, it will be presented the applications of this Multiphysics tool to advanced sintering approaches such as transparent ceramics, complex shapes, flash sintering.
Title: SEM imaging of biofilms supported on natural zeolite
Biography:
Nataliia Gorodylova has completed her PhD in chemical sciences at the age of 26 from Taras Shevchenko National University of Kyiv, Ukraine. Later, Nataliia has accomplished Postdoctoral Studies at University of Pardubice, Czech Republic in the field of inorganic technology. Today, Nataliia is a postdoctoral researcher working on joint BRGM and GREMAN project in France focused on biofilm growth on inorganic materials and its potential utilization for bioremediation of the pesticide-polluted soil. She has published more than 30 papers in reputed journals in the field of materials science and inorganic technology.
Abstract:
SEM imaging of biological samples such as biofilms supported on natural inorganic material is not an easy task. The main issues that should be taken into account are:
- Non-conducting surface: when bombarded with electrons, artefacts known as charging are produced. It manifests as image distortion, specimen damage, and dark areas within an image due to repulsion of electrons. In order to prevent radiation and thermal damage to structures, specimen can be coated with conductive material (sputter coating with Au, Pd or carbon). Alternatively, specimen can be observed in ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, etc).
- Low atomic weight: biological samples are composed of low atomic number elements thus the electron beam penetration is deep giving rise to a large interaction volume. This is manifested in signal weakening and low resolution. As a solution, metal sputter coating and/or additional staining step of biofilm can be used.
- Instability of microorganisms in high-vacuum: due to internal pressure biological samples are unstable in high vacuum. Therefore, specimen dehydration is a crucially important step in SEM imaging of microorganisms. Common approaches include critical point drying, freeze drying and chemical drying (ethanol/HDMS). In order to reduce deformation of the specimen during drying, biological samples are usually fixed using glutaraldehyde and/or osmium tetroxide. Alternatively, fixed specimens can be observed in ionic liquid that exclude need in drying.
Some of the mentioned approaches are evaluated and compared on biofilm formed on natural zeolite. This contribution is devoted to the discussion of advantages and disadvantages of the tested approaches.
Oral Session 1:
- Metallurgy | Graphene and 2D Materials | Nanotechnology in Materials Science | Polymer Science and Engineering
Title: Corrosion protection and flammability characteristics of aerospace grade magnesium elektronTM 43 for use in aircraft cabin interiors
Biography:
Sarah Baillio has completed graduate studies at the University of North Texas from the Department of Materials Science and Engineering. Sarah Baillio has worked for Boeing, Embraer, and Zodiac Aerospace and has been privileged to participate in the International Materials Fire Test Working Group meetings sponsored by international aviation authority organizations.
Abstract:
Magnesium alloys exhibit desirable properties for use in transportation technology. In particular, the low density and high specific strength of these alloys is of interest to the aerospace community. However, the concerns of flammability and susceptibility to corrosion have limited the use of magnesium alloys within the aircraft cabin. This work studies a magnesium alloy containing rare earth elements designed to increase resistance to ignition while lowering rate of corrosion. The microstructure of the alloy was documented using scanning electron microscopy. Specimens underwent salt spray testing and the corrosion products were examined using energy dispersive spectroscopy.
Title: Improving electrochemical performance of Si-based electrode via gradient Si concentration
Biography:
Zhenbin Gua is focused on the studies on bioinspired mechanics and materials and has published 7 papers in this field during his PhD study. Recently, his research interest has been extended to the mechanical behavior of anode materials for LIBs. The idea of using gradient strategies to improve the performance of LIBs is inspired by previous studies in both areas.
Abstract:
Silicon (Si) has long been regarded as one of the most promising anode materials for the next-generation Lithium-Ion Batteries (LIBs) due to its exceptional specific capacity and apt working voltage. However, the dramatic volume change of Si during lithiation/delithiation processes leads to the delamination between the current collector and the electrode materials, resulting in the poor stability and degradation of electrochemical performance of the LIB. Inspired by the functional graded design in natural biomaterials, here we propose to solve the interfacial delamination problem by graded electrode in which the Si composition is distributed in a graded way. The prepared graded electrodes especially those after gradient optimization are found quite successful in alleviating the interfacial delamination, resulting in higher capacity and capacity retention, higher coulombic efficiency, higher effective mass loading in comparison to the traditional ones. Such graded electrode can be applied together with other strategies for solving the large volume change problem of Si and can be easily produced by the existing manufacturing facilities of electrode. This work provides a guideline for the design and manufacture of the graded Si-based electrodes for LIBs.
Title: Heterogeneous catalytic reduction of anthropogenic pollutant, 4-nitrophenol by Au/AC nanocatalysts
Biography:
Venkataraman Vishwanathan is Professor at Botho University. He has more than 10 years’ experience in teaching. He has 1,091 Citations and he has completed 43 Research items.
Abstract:
Activated carbon-supported gold nanocatalysts (Au/AC) were synthesized by the Homogeneous Deposition–Precipitation (HDP) method by adding dropwise of NaBH4 into the aqueous solution of HAuCl4. Catalytic activity of these nanocatalysts was investigated for the reduction of the anthropogenic pollutant, 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The physico-chemical properties of the nanocatalysts were characterized by XRD, TEM, BET surface area, pore size distribution, XPS and UV–vis spectroscopy techniques. Gold nanoparticles (Au NPs) with high percentage of dispersion on a high surface area activated carbon (AC) support, show excellent catalytic performance in terms of activity and selectivity for 4-NP reduction. The reaction rate was measured to be pseudo-first-order with respect to 4-NP. The pseudo-first-order rate constant and the activation energy were estimated to be 1.2–4.2 × 10−3 s−1 at 25oC and 26.38 kJ mol−1, respectively. Moreover, the catalytic activity was found to increase with increase in Au content of the catalyst. The reusability of the nanocatalyst showed a better reduction of 4-NP to 4-AP even after 5 successive re-cycles. The foregoing study clearly suggests that synthesis of Au/AC nanocatalysts by HDP method is efficient towards the development of a newer and a novel catalyst.
Title: Femtosecond laser irradiation for hot spots mapping on the surface of plasmonic nanostructures
Biography:
Nadia A. Abdulrahman has completed her PhD on Aug. 2014 at the age of 41 at University of Glasgow- College of Science and Engineering-School of Chemistry/UK. She is a lecturer of physical chemistry and has been serving as an academic at University of Baghdad-College of Science-Department of Chemistry/Iraq. She has published six papers in Iraqis, British and Americans journals. During her PhD course and afterword, she had learned: how to design and fabricate 2D chiral and achiral plasmonic nanostructures (metamaterials) via nanofabrication technology, how to use SEM and AFM microscopy for metamaterials and biological molecules imaging, running UV and CD spectroscopy for metamaterials and biological molecules characterization, running SHG spectroscopy to characterize non-linear optical activity of 2D chiral plasmonic metamaterials, using femtosecond Laser irradiation to map Hot-Spots on the surface of chiral plasmonic metamaterials and using XRD spectroscopy and Williamson-Hall analysis to characterize crystal lattice of nanoparticles. In addition, she has learned the principles of scientific writing and hence, starts reviewing scientific articles, papers and theses.
Abstract:
Novel method for visualising plasmonic hot spots upon plsmonic surfaces of gold nanostructures. Femtosecond laser pulses have been used to map the locations of localised high intensity electromagnetic fields i.e. the locations of hot spots. Upon irradiation with 800 nm femtosecond laser pulses, which may be linearly or circularly polarised, it is possible to reveal the locations of plasmonic hot spots since the nanostructures are physically damaged i.e. undergo melting by the intense heat generated by femtosecond laser pulse irradiation. SEM microscopy was used subsequently to map the surface of the nanostructures to show which areas have been damaged, and hence reveal the locations of the hot spots. 2D arrays of quadric units (arranged in a racemic fashion) consisting of two patterns: gammadions and G-like shapes, have been used as plasmonic chiral nanostructures. It has been found that irradiation with linearly polarised light affected segments that are perpendicular to the polarisation direction of the incident beam. However, irradiation with circularly polarised light affected both horizontal and vertical segments of the nanostructures regardless the sense of individual features (i.e. left-handed or right-handed) or the sense of the circular polarisation of the incident beam (i.e. clockwise or counter-clockwise). Hence, no enantio-selectivity was observed.
Title: Gamma radiation resistant behaviour of polysulfone-nanodiamond mixed matrix membrane: The effect of nanoparticle size and loading
Biography:
Amita Bedar is pursuing her PhD from Homi Bhabha National Institute, Bhabha Atomic Reseach Centre, Mumbai (India). She is working on the development of radiation resistant polymeric nanocomposite membrane for the radioactive effluent treatment. She has completed her M. tech. in 2014 from Indian Institute of Technology Gandhinagar, India. During M. Tech., She worked on the synthesis of boron based 2-D nanosheet and publish her work in Nature Scientific Reports.
Abstract:
Diamond is a well-known hard and radiation resistant material, and has got several uses in nuclear industry. Owing to the unique properties of the NanoDiamond (ND), an attempt has been made to develop gamma radiation resistant polymeric nanocomposite membrane by impregnating different sizes (10, 250 and 500 nm) and loadings (0.1, 0.5, 1 and 2%) of ND into polysulfone (Psf) host matrix. The synthesized membranes were irradiated with 250, 500 and 1000 kGy of gamma radiation with a dose rate of about 1 kGy h−1. The pure water permeability and solute rejection studies (with solutes of polyethylene oxide of molecular weight 100 kDa) of the unirradiated and irradiated membranes were carried out. The morphology, topography and mechanical properties of the membranes were analysed using scanning electron microscopy, atomic force microscopy and Universal Testing Machine (UTM), respectively. The unirradiated composite membranes reinforced with ND of 10 nm was observed to have a defect-free surface, while those with 250 and 500 nm sized NDs are having deteriorated morphology, owing to larger particle size of the filler. The performance (flux and selectivity) and UTM analyses of (un)irradiated membranes up to 1000 kGy showed a similar trend in the radiation stability of nanocomposites, with the 10 nm sized nanodiamond impregnated matrix being the most radiation resistant. Findings confirm that these radiation resistant Psf-ND mixed matrix membranes can have potential applications in nuclear fuel cycle, circumventing the practical limitations encountered in the deployment of polymeric membranes in this domain.
Title: Study on the crystallization of A356 alloy containing nanoparticles
Biography:
Pavel Kuzmanov has completed his PhD at the age of 45 years from Institute of Metal Science, Equipment and Technologies with Hydroaerodynamics Centre "Acad. A. Balevski" - Bulgarian Academy of Sciences – Sofia, Bulgaria. He works as assistant professor in the same institute. He has published more than 10 papers in reputed journals.
Abstract:
A study of cast alloy A356, modified with different types of nanoparticles is carried out. SiC, AlN, TiN, clad with Cu, Ag and Al are used. The cladding is done by: currentless chemical method, extrusion of a composite rod, compression of tablets and mechano-chemical treatment in a planetary mill. The resulting NanoCompositions (NCs) are introduced into the crucible of a furnace. Thereafter homogenization using an impeller is performed. Casting of the samples takes place in thin-walled steel containers. During the cooling and crystallization of the alloy the non-stationary temperature is measured. Data of temperature dependences on time has been obtained and the magnitude of overcooling with and without NCs is determined. Reduction of the overcooling and grain refinement for the samples with NCs was found, as the average grain diameter decreases from 21% to 60%. The research provide new information of the influence of NCs on the crystallisation process of alloy A356.
Keynote Session:
Title: From high temperature superconductivity to Li-ion battery
Biography:
Maw-Kuen Wu is a distinguished research fellow at the Institute of Physics, Academia Sinica in Taiwan. He is a member of the Academia Sinica, Taiwan, a Foreign Associate of the US National Academy of Sciences as a Foreign Associate, and a member of the Academy of the Developing Countries. He has received awards including the Comstock prize, the Bernd T. Matthias Prize, the Humboldt Research Award, the Nikkei Asia Prize, the Ettore Majorana-Erice-Science Prize of Italy, and the Presidential Science Prize of Taiwan.
Abstract:
High temperature superconductivity observed in the cuprates and FeSe-based materials are strongly correlated with the novel Mott metal-insulator transition, which exists in many transition-metal chalcogenides. In this presentation, review the discoveries, which personally involved, of the high Tc cuprate and FeSe superconductors. I shall discuss more in depth the current understanding regarding the origin of high Tc superconductivity based on our recent results on FeSe and related materials. The results suggest that the presence of ordered Fe-vacancy results in the metal-insulator transition. A proper treatment, either thermally or chemically, can disrupt the vacancy order to induce charge transfers between transition metal d-orbital and the chalcogen p-orbital, and subsequently lead to superconductivity. The concept of charge transfer from transition-metal oxides is the key to the development of high energy capacity cathode material for Li-ion battery . Herein I’ll present a designed Li-rich cathode material Li1.083Ni0.333Co0.083Mn0.5O2, which dominated by cationic redox reaction, exhibits high specific capacity and much less voltage fade. By reducing the excess lithium content to decrease the probability of Mn4+, Li+ and On- short range ordering, the designed material significantly suppresses the voltage fade at around 3.0/3.3 V that provides a different prospect in evolution of structural chemistry for Li-rich materials. A 60 mAh pouch cell displays 200 mAh/g initial capacity and 85% retention after 400 cycles in 0.2C charge/discharge rate. I’ll present the details of the mechanism responsible for the long cycle-life test.
Title: To be updated soon
Biography:
Falah H. Hussein has received a PhD from Nottingham University (England). He is working now with his research group at the Faculty of Pharmacy, University of Babylon. His researches now focusing on synthetizing nanoparticles and carbon nanotubes and studying the photocatalytic activity and drug delivery by nanomaterials.
He has occupied several top scientific and academic administrative positions, improving teaching, research, and higher education in Iraq. For eighteen years, he served as the Dean of college of Education, Dean of college of Science and President of University in IRAQ. During these 18 years, he established many colleges, scientific departments, research centers and MSc and PhD studies.
He has received numerous awards, including Three international (Kolbenkian Award), National award of Environment in Iraq (2001) and other more than 100 National awards. He has got the Medal of Scientist distinguishing in Iraq from the Ministry of Higher Education and Scientific Research in Iraq (2013). He got NISA Award for Outstanding Iraqi Research on 2017 for the Best Collaborative Paper published article during 2016.
He has studied, teaching and published many articles on chemical, biological, radiational and nuclear safety and security and chairing the organizing committee of the 1st 2nd and 3rd National CBRN Safety and Security Conferences in Iraq during 2016-2018, environmental protection, wastewater treatments, hydrogen production and nanotechnology. He is one of the founders of the Arab Renewable energy Commission (AREC). He was awarded twelve patents and published more than 160 articles in different national and international journals.
He is chairing the central committee of CBRN safety and security in Babylon University and he is member in Ministerial CBRN committee in MOHESR. He has participated in more than 100 workshops about CBRN safety and security in USA, Malaysia, Turkey, Germany, Czech Republic, Jordan and Iraq.
Abstract:
To be updated soon
Title: Green synthesis of mesoporous carbons from tannins
Biography:
Vanessa Fierro pursued doctoral researches at the Institute of Carbochemistry (ICB-CSIC) and obtained her PhD from Zaragoza University (Spain). After working several years as a researcher at French Institute of Petroleum, at the Institute of Research on Catalysis and the Environment of Lyon (France) then at the Chemical Engineering School of Tarragona (Spain), she is a CNRS Research Director as well as a member of the Technical Group Coal 2 of the Research Fund for Coal and Steel (RFCS). She currently works at Institut Jean Lamour (France), a joint University of Lorraine-CNRS laboratory, where she leads the Bio-sourced Materials Research Team. She has more than 250 scientific publications, an h-index of 48 and an extensive background in the area of porous carbon materials for energy and environmental applications.
Abstract:
An easy and one-pot synthesis method to produce mesoporous carbons through ball-milling will be presented. The method is also environment-friendly, due to the use of a natural and renewable carbon precursor, tannin, and to the absence of toxic or hazardous substances during the synthesis.
These mesoporous carbons were prepared by mixing tannin (T), Pluronic® F127 (P) and water (W) without using any crosslinker. The effect of key parameters such as milling time, pH of added water and P:W weight ratio was studied. After carbonization at 900°C of the paste-like materials recovered from milling, the resultant carbon materials had an initial BET area of ~600 m2 g-1. Depending on the P:W ratio, they were perfectly ordered (OMC), with a 2D hexagonal geometry, or disordered (DMC). The mesoporous order proved to be thermally stable under inert atmosphere up to 1500 °C while, upon activation the BET area increased up to ~1900 m2 g-1.
CO2 activation on selected OMCs and DMCs allowed improving the textural properties, i.e., surface area, micro and mesoporous volume and pore connectivity. CO2 activation was more effective on DMCs as shorter activation times were needed. The easier development of textural properties in the case of DMCs might be due to the higher residence time of CO2 in the particle since the carbon texture, determined by Raman, and the heteroatoms content on the surface were identical.
These materials should find relevant applications in environmental remediation strategies for oil spills, in selective CO2 adsorption from humid gases or as electrodes of supercapacitors using aqueous or organic electrolytes, among others. Some of them will be presented.
Oral Session 1:
- Advanced Materials and Devices | Energy Materials | Characterization and Testing of Materials | Ceramics and Composite Materials | Materials in Industry | Materials Chemistry
Title: Intentionally made amorphous substance to quantify unintentionally produced amorphous materials: Decades of hands-on experience
Biography:
Mridul Majumder is a Founder, Director of M2M Pharmaceuticals Ltd. Before setting up M2M Pharma in 2016, Mridul had worked for a CRO over 12 years in early stage product development especially related to material science for inhalation drug delivery. Mridul is an honorary lecturer at UCL School of Pharmacy, London; Fellow of Royal Society of Chemistry and a Member of Academy of Pharmaceutical Sciences (APS) in the UK.
By education, Mridul is a Pharmaceutical scientist with a PhD in Pharmaceutics from University of Reading (2013). Before that, he did his MSc Drug Delivery from UCL School of Pharmacy, London back in 2002 and his MPharm and BPharm were from Jadavpur University (2000) and Bangalore University (1997) respectively.
Abstract:
Milling induced disordered material, amorphous, is highly energetic and a considerable portion of these particles significantly influence the cohesive and adhesive balance (CAB) of micronised particles. This behaviour results in varying fine particle fraction (FPF) which ultimately affects dry powder inhaler (DPI) performance. There is also an important aspect of milled materials that they are heterogenous in nature. Due to the different particle size, shape, surface area, high energetics, it has been a challenge to produce stable DPI product without a deep understanding of the physical properties of milled and un-milled samples, their behaviour and control over their processing. It is reasonable for the regulatory authorities (e.g. FDA, MHRA) to seek a suitable analytical method to quantify amorphous content, control over amorphous materials, and they may assign limits for amorphous content in batches that are to be used for commercial purposes. There has been extensive work carried out for amorphous content determination using various techniques that has added invaluable insights to fundamental research. However, hands-on experience of handling numerous inhaled APIs and their corresponding products motivated this author to highlight practical approaches required to develop a reliable method (s) for this challenging subject. Research in this field clearly demonstrates that given a right skills, knowledge and experience, a suitable method can be developed which ensures reproducible data consistently. There is no standard method to quantify amorphous materials in a crystalline bulk for pharmaceutical solids. As all such particles have different physicochemical properties, it is important that the method is developed as per the sensitivity of the solids to the technique which ensures reproducible data in a robust manner.
Title: Incorporation of physical chemical identifiers into solid oral dosage form drug products for anti-counterfeiting
Biography:
Sushil Kumar Sharma has QA professional with more than 4 years’ experience in QA for the pharma, chemical and Pharma industries. He is also Assistant Professor (Organic Chemistry) Department of chemistry, Faculty of Science.
Abstract:
This document is intended to provide guidance to pharmaceutical manufacturers who want to use Physical- Chemical Identifiers (PCIDs) in solid oral dosage forms (SODFs). A PCID is a substance or combination of substances possessing a unique physical or chemical property that unequivocally identifies and authenticates a drug product or dosage form. This guidance provides recommendations to pharmaceutical manufacturers on design considerations for incorporating PCIDS into SODFs, supporting documentation to be submitted in New Drug Applications (NDAs) and Abbreviated New Drug Applications (ANDAs) to address the proposed incorporation of PCIDs in SODFs, supporting documentation to be submitted in post-approval submissions to report or request approval to incorporate PCIDs into SODFs, and procedures for reporting or requesting approval to incorporate PCIDs into SODFs as a post-approval change. The incorporation of components or features used in radiofrequency identification for drug products is outside the scope of this guidance. In addition, this guidance does not apply to manufacturing or formulation changes, made in conjunction with the addition of a PCID, that go beyond simply inserting the PCID into a blending or mixing operation (e.g., adding a PCID to a non-functional tablet film coating is covered by this guidance, but adding a non-functional film coating that contains a PCID to a previously uncoated tablet involves manufacturing changes that are not covered by this guidance). The incorporation of a PCID into the packaging or labeling is not covered in this guidance. Other guidance documents, which may be applicable to proposed changes outside the scope of this guidance, are located on FDA’s guidance Web site 2 and should be consulted to help to determine whether additional reporting or approval procedures may apply to proposed changes outside the scope of this guidance. FDA's guidance documents, including this guidance, do not establish legally enforceable responsibilities. Instead, guidance documents describe the Agency's current thinking on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited. The use of the word should in an Agency guidance document means that something is suggested or recommended, but not required.
Title: Investigation of some mechanical, and physical properties of bioblend nanocomposites
Biography:
Mohammed K.J. Alobaidi is Senior Assistant Professor for Institute of Metal Science, Equipment and Technologies with Hydroaerodynamics Centre. He has Citations 27.
Abstract:
Chitosan (CH) / Poly (1-vinylpyrrolidone-co-vinyl acetate) (PVP-co-VAc) blend (50:50) [CH/(PVP-co-VAc)] reinforced with two particle size of TiO2 nanoparticles were prepared by solution casting method. Mechanical tensile strength, Elongation, Young modulus, Thermal conductivity, water absorption, and FTIR analysis were studied for blend and nanocomposites. The tensile results show that the tensile strength and Young’s modulus of the nanocomposite films were improved compared with polymer blend [CH/(PVP-co-VAc)] film. The mechanical properties of the polymer blend were improved by the addition of TiO2 with significant increases in Young’s modulus (from 2274 MPa to ~2876 MPa) and tensile strength (from 47.87 MPa to 49.65MPa). Strong interfacial bonding between the TiO2 nanoparticles and the [CH/(PVP-co-VAc)], homogenous distribution of the nanoparticles in [CH/(PVP-co-VAc)] are supportive of markedly improved mechanical strength. The thermal accessibility of the [CH/(PVP-co-VAc)] blend and [CH/(PVP-co-VAc)] /TiO2 nanocomposites films show that it decreased in the adding of nanoparticle TiO2. The solubility calculations demonstrate that the nanocomposite has enhanced water resistance. The weight gain decreased with the addition of nano TiO2. Blending chitosan CH with (PVP-co-VAc) improved strength and young modules of the film and increased water uptake because hydrophilic of the two polymers blend films.
Title: Adsorption-desorption cycle of chemisorbed CO2 on the surface of SnO2 and Co-SnO2 for room temperature gas sensor
Biography:
Mohamed A. Basyooni has completed M.Sc. degree in Experimental Physical Chemistry with honors at Nanophotonics and Applications Lab, Faculty of Science, Beni-Suef University in 2016. Now, he is a PhD resaerch student at Department of Nano Science and Nano Engineering, Institute of Science and Technology, University of Konya Necmettin Erbakan-Turkey and Institute of Materials Research and Engineering (IMRE)-Singapore. He was working in semiconductor technology for many years to develop a room temperature gas sensors based on metal oxide semiconductors nanostructure thin films. He developed a room temperature gas sensor with more than 80% sensitivity towards carbon dioxide based on novel wrinkle porous net-work nanostructure-based sodium doped zinc oxide, published in Nature. Currently, he is working in energy efficient materials, vanadium dioxide (VO2) based smart coatings and the gas sesnsing behavior.
Abstract:
Undoped and cobalt doped Tin oxide (SnO2 and SnO2: Co) thin films of varying thickness were successfully fabricated by the sol-gel spin coating technique. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of the number of layers on the structural and optical properties of SnO2 and SnO2: Co films were studied. The crystallite size of the pure SnO2 films increased from 7.7 to 31.1 nm by increasing the number of layers from 12 to 24. The crystallinity of the film was enhanced when the annealing temperature was increased from 400 to 500oC. However, it reduced by incorporating Co atoms. Transmittance and optical band gap of the SnO2 film decreased by increasing the number of layers or after Co doping. The 8% Co-doped film shows relatively higher sensitivity for CO2 gas at room temperature (RT) compared to un-doped SnO2 film with a rate of 0.116/sccm for Co-SnO2. In this study, the carbon dioxide gas acted as an oxidizing agent that caused the increase in the electrical resistance of the sensor signified by the increase in voltage reading. The trapped negative charges in the oxygen species caused an upward band bending in the SnO2 film, thus increasing its resistance compared to the situation before CO2 gas exposure. The response and recovery times increased as the CO2 concentration increased. These results demonstrate the possibility of optimizing the physical properties of the SnO2 film for sensing and optoelectronic applications.
