Day :
- Track 1: Nanomaterials Particles and Applications, Track 4: Nano Electronics, Track 5: Molecular Nanotechnology, Track 9: Reinforcements in Nanotechnology
Location: DoubleTree by Hilton Hotel Cape Town
Chair
Bonex W Mwakikunga
DST/CSIR National Centre for Nano-Structured Materials, South Africa
Co-Chair
Annie Chimphango
Stellenbosch University, South Africa
Session Introduction
Yoshio Kobayashi
Ibaraki University,Japan
Title: Preparation of Au/silica/cellulose nanoparticle colloid solution and its use in X-ray imaging process
Time : 10:30-10:55
Biography:
Yoshio Kobayashi received his B. S. (1988), M. S. (1990), and Ph. D. (1993) degrees from Tohoku University. He worked as a Research Associate at Tohoku University (1993-1997), as a Postdoctoral Researcher at Colorado State University (1997-1998), as a Postdoctoral Researcher at Kansas State University (1998-1999), as a Visiting Researcher at Universidade de Vigo (1999-2001), as a Research Associate at Tohoku University (2001-2002), and as an Associate Professor at Tohoku University (2002-2006). He is a Professor of Ibaraki University, and has published more than 150 papers in reputed journals.
Abstract:
X-ray imaging of mice using a colloid solution of Au nanoparticles that were coated with silica and subsequently surface-modified with carboxymethylcellulose (CMC) (Au/SiO2/CMC) was performed in this work. The silica-coating for Au nanoparticles and the amination for silica-coated particles were simultaneously performed in the presence of the Au nanoparticles with a size of 17.9 nm, which were prepared by reducing Au ions (III) with sodium citrate in water at 80°C and by surface-modifying the Au nanoparticles with (3-aminopropyl)-trimethoxysilane, by a sol-gel process using tetraethylorthosilicate, (3-aminopropyl)-triethoxysilane, water and sodium hydroxide (Au/SiO2-NH2). The surface modification of Au/SiO2-NH2 particles with CMC was performed by simply adding CMC with carboxyl groups that react with an amino group to the Au/SiO2-NH2 particle colloid solution. The as-prepared the Au/SiO2/CMC particle colloid solution was concentrated by centrifugation for measurements using computed tomography (CT). Figure 1 shows a photograph of the concentrated particle colloid solution and a transmittance electron microscopy image of the Au/SiO2/CMC particles in the concentrated colloid solution. Most particles contained a single core of the Au nanoparticles. Their particle size was 67.4±5.4 nm. A CT value of the Au/SiO2/CMC particle colloid solution with a Au concentration of 0.043 M was as high as 344±12 Hounsfield units (HU). This value corresponded to 8.0×103 HU/M with respect to the Au concentration, which was larger than that of Iopamiron 300, a commercial X-ray contrast agent. Mouse tissues were imaged following injection of the Au/SiO2/CMC particle colloid solution.
Zenixole R Tshentu
Nelson Mandela Metropolitan University, South Africa
Title: Polymer nanofibers for desulfurization of fuels
Biography:
Prof. Dr. Zenixole R. Tshentu is currently an associate professor of analytical/inorganic chemistry at the Nelson Mandela Metropolitan University (NMMU) in South Africa. He completed his PhD studies in Inorganic Chemistry at NMMU in 2005 and was offered a lectureship position at the Rhodes University Chemistry Department where he remained for 7 years until his move back to NMMU in 2013 as associate professor. He has published 64 articles in peer-reviewed national and international journals as well as three book chapters. He has experience in the solid state and solution studies of transition metals chemistry as well as using inorganic/organic polymer materials in separation technology and in heterogeneous catalysis. He has been involved in several projects such as designing organic extractants for the separation of base metals and platinum group metals via solvent extraction and ion exchange processes, designing ligands for the stabilization of therapeutic metals in biological systems, and designing catalysts for selective oxidation of sulfur compounds in fuels followed by selective adsorption of sulfones using molecularly imprinted polymers. The functional chemistry is typically hosted in microscale materials as well as nanomaterials such as nanofobers. He terms his philosophy “the quest for selectivity and specificity”.
Abstract:
This presentation will uncover progress in the fabrication and catalytic applications of various metal-based catalysts immobilized unto nanofibers. It will also highlight the challenges associated with the use of electrospun nanofibers in catalysis. Herein, we also explore the possible use of polymer-supported oxovanadium(IV)-based catalysts for the oxidation of organosulfur compounds in hydro treated fuel followed by adsorption of polar sulfone compounds using molecularly imprinted polymers in a form of nanofibers. The application of the oxidation and the adsorption steps to a mildly hydro-treated diesel sample has been demonstrated to reach less than 2 ppm S content.
Rodrigo Segura
Valparaiso University, Chile
Title: Graphene and Titanium dioxide based hybrid materials as photoelectron catalytic systems
Time : 11:40-12:05
Biography:
Rodrigo Segura received his PhD. Degree in Chemistry at the Universidad de Concepción in 2004. Since 2009, Rodrigo Segura is Professor of Inorganic Chemistry in the Institute of Chemistry and Biochemistry at the Universidad de Valparaíso. His main fields of research encompass Synthesis, Characterization and Properties of Nanomaterials. Lasts years He has been devoted to the study of Carbon Nanostructures, specially the synthesis of carbon nanotubes alloyed with metal and semiconductor nanoparticles for sensing and energy applications.
Abstract:
Graphene layers represent a good candidate to develop composed photocatalysts. Due to its high electronic conductivity It can prevent the recombination of the electron-hole pair and act as a doping agent and even extend the range of light absorption of a semiconductor such as the TiO2. In this contribution thin TiO2 layers were grown on few layers graphene (FLG) in order to prepare hybrid photocatalysts with the properties of both materials. FLGs were synthesized by chemical vapor deposition (CVD) at 1000 °C using acetylene as carbon source and copper as substrate. After synthesis the FLGs were transferred to silicon substrates and TiO2 layers were deposited on FLG by decomposition of titanium tetraisopropoxide in a CVD system. The photocatalytic performances of these materials were evaluated by measurements of photocurrent in a 3-electrode cell assembly by using a solar simulator and a potentiostat. The photocurrent results show that the FLG is very electroactive presenting a similar behaviour under both dark and illumination; on the other hand the TiO2 layers grown over silicon show the typical behaviour of a photoactive semiconductor since these samples exhibit a raise in the current with the applied potential only when It is illuminated. The hybrid Si-FLG-TiO2 material present in principle a similar behaviour of Si-FLG but when we made a chronoamperometry alternating dark and light cycles an discounting the dark response It is possible to observe a similar performance than Si-TiO2 sample. Both materials graphene and titanium dioxide have preserved their properties after the assembly. The authors acknowledge the financial support of Fondecyt 1121203.
Shivani Bhardwaj Mishra
University of South Africa, South Africa
Title: Nanoscale sovereignty for waste water remediation
Time : 12:05-12:30
Biography:
Prof. Shivani Bhardwaj Mishra has completed her PhD at the age of 30 years from Jamia Millia Islamia, New Delhi and postdoctoral studies from University of the Free State & University of Johannesburg. She is the Professor of Nanotechnology at University of South Africa which is a premier University. She has published 2 books, 30 book chapters and around 65 papers in reputed journals and also serving as reviewer and member of scientific board of repute.
Abstract:
Nanomaterials offer unique and unexpected material properties and this is due to the fact that at nanoscale, materials can be ‘tuned’ to build faster, lighter, stronger, more efficient and stimuli responsive materials. Such properties of nanomaterials provide a platform for eco-toxicological based research investigations. Presently, there is limited knowledge and understanding for a number of major uncertainties with respect to chemical behavior, chemical and biological interactions and toxicological properties of engineered nanomaterials. Clean water is always essential which often calls for a cheap and efficient water purification system. Nanomaterials are being used to develop more cost-effective and high-performance water treatment systems. Remediation is the process of pollutant transformation from toxic to less toxic in water. The focus of the talk will be the recent advancement and development of the nanoscale sovereignty for the waste water remediation.
Biography:
Dr. Arjun Maity earned his PhD degree in chemistry from University of Calcutta, India. After that he joint at DST/CSIR National Centre for Nanostructured Materials (NCNSM), Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), as a post-doctoral fellow. In 2009, he joint at Polymers and Composites department, CSIR, as a senior Researcher. Currently he is principal researcher at NCNSM, CSIR. His research interests are synthesis and engineering of nanocomposites for environmental applications. He has published more than 88 papers in reputed journals.
Abstract:
In recent years, extensive efforts have been devoted to develop nanostructured materials with unique reactivity and functionality for environmental clean-up. The presence of heavy metals such as Cr, Hg, As, Pb, Ni, Co etc. in both fresh water sources and industrial wastewater, is a critical health and environmental issue due to their high toxicity and bioaccumulation through the food chain and hence in the human body. Nowadays, smart polymeric nanostructured materials based on polyaniline and polypyrrole are promising materials in water treatment because they are cheap, easy to prepare, non-toxic, it displays high adsorption capacity and it also has ion exchange property. Recently, we have developed conducting polymer based nanocomposites via in-situ polymerization technique, for the removal of highly toxic pollutants. Adsorption of pollutants on the surface of the adsorbent was confirmed by the ATR-FTIR and XPS. XPS studies also provided mechanistic aspects in detailed. Desorption studies showed that in spite of the limited recovery of the adsorbate form the adsorbent; the regenerated adsorbent could be reused successfully without appreciable loss of its original capacity. On the other hand, spent adsorbents could be re-used for different applications: catalysis, antimicrobial activity and gas sensor.
Annie Chimphango
Stellenbosch University, South Africa
Title: Comparison of morphological properties of xylan nanohydrogels produced by enzymatic and chemical methods
Biography:
Dr. Annie Chimphango is a Senior Lecture at Stellenbosch University, Department of Process Engineering. She holds a Master Degree in Agricultural and Bioresource Engineering from McGill University, Canada and a PhD in Chemical Engineering from Stellenbosch University.. She has published papers in reputable Journals on enzymatic modification of hemicelluloses to form nano-hydrogels and their application in pulp and paper and their use as encapsulation matrix for bioactive substances . Her research focus is on value addition to agro-residues and process waste through production of high value materials such as hydrogels and nanocellulose using biological methods.
Abstract:
Xylan solubility properties were modified using enzymatic and chemical methods to produce nanohydrogels. The enzymatic modification involved recombinant α-L-arabinofuranosidase that selectively removed arabinose side chains whereas the chemical method involved the coacervation through neutralization process that involved hydrochloric acid and sodium hydroxide. Furthermore, the effect of time, xylan concentration and presence of plasticizers, thus polyethylene glycol 1000 (PEG 1000), polyoxyethylene (20) sorbitan monolaurate [Tween 20], on particle size, surface charge and stability was investigated. The mean particle diameter, zeta potential, were measured by a Zetasizer Nano ZS90 that used Dynamic light scattering. In addition, the morphological profile of the particles was assessed using a microscope equipped with a micrometer grid, connected to a camera. The sugars from the enzymatic hydrolysis were analyzed using the High Performance Liquid Chromatography, Doinex Ultimate 3000, equipped with Prevail Carbohydrate ES analytical column, and ELS2100 Evaporative Light Scattering detector. Tween 20 plasticizer prevented aggregation of the particles. Over 80% of the particles formed using the chemical method attained a mean diameter ranged from 153- 853 nm and a zeta potential of -28mV. On the other hand the nano particles with sizes as low as 21 nm were produced by enzymatic method with Zeta potential of close to -20 mV. The presence of plasticisers during formation of nano particles to some extent prevented aggregation behavior of the nano-particlesr. In enzymatic production, size distribution was dependent on xylan concentration. These results demonstrates the potential to diversify industrial application of xylan.
Olatunji Ololade
University of Lagos, Nigeria
Title: Microneedles from fishscale nanocellulose blends using low temperature mechanical press method
Biography:
Ololade Olatunji is a Lecturer at the University of Lagos, Nigeria. She completed ar PhD in chemical engineering department Loughborough University UK. She has a number of publication in the area of microneedles for transdermal drug delivery and is recently editor of the book Natural Polymers industry techniques and application, Published by Springer (in production). She is also guest editor of the special Issue on Microneedles in the MDPI journal of Pharmaceutics. She previously served as Senior Research officer at the Federal Institute of Industrial Research Oshodi (FIIRO) in Lagos, Nigeria.
Abstract:
A fish scale biopolymer blended with nanocellulose crystals is used for production of microneedles by appliying mechanical press microfabrication, and the effect of nanocelullose on the microfabrication, water absorption, moisture stability and mechanical properties of the microneedles are reported. The results show that microneedles produced from the nanocellulose loaded fish scale biopolymer requires higher temperature for micromoulding (80 o C + 5 o C) than microneedles from only fish scale biopolymer which were mouldable at 50 o C + 5 o C. The mechanical properties of the fish scale biopolymer nanocellulose (FSBPNC) films showed that the addition of nanocellulose (NC) resulted in lower elongation and higher tensile stress compared to fish scale biopolymer (FSBP) films. The nanocellulose also prevented dissolution of the needles and absorbed up to 300 % and 234 % its own weight in water (8 and 12 % w/w NC/FSBP), whereas FSBP films dissolved completely within 1 minute, indicating that the FSBPNC films can be used to produce microneedles with prolonged dissolution rate. FTIR spectrometry of the FSBP films was compared with the FSBPNC films and the NC gels. The FTIR showed typical peaks for fish scale polymer and nanocellulose with evidence of interactions. SEM micrographs showed relatively good dispersion of NC in FSBP at both NC contents corresponding to 8% and 12% w/w NC/FSBP respectively.
K. Kaviyarasu
University of South Africa, South Africa
Title: Looking for quantum size effects in Zr-Pb-O2 one dimensional nanorods
Biography:
Kaviyarasu obtained his Master of Science (M.Sc.) & Master of Philosophy (M.Phil.) degree in Physics from Loyola College (Autonomous), Chennai, affiliated to the University of Madras, India. He has carried out research on Semiconductor Metal Oxide Nanocrystals & Synthesis and characterization of Hybrid Nanomaterials for energy applications. During the course of his research work, he has published 33 papers in International/National Journals and presented 35 papers in National and International conferences. Currently his a Postdoctoral researcher at UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), South Africa. My research is directed primarily toward developing and applying modern material design for the understanding and prediction of Physico - Chemical processes ranging from the molecular to the nanoscale to full-size engineering applications, using a multidisplinary approach that Physics, Chemistry, and Materials science. Work is closely coupled with synthesis and characterization of Hybrid Nanomaterials at the Center for Nanoscience and Nanotechnology, where scientific focus is on using theory and multiscale simulations and modeling for providing interpretive and predictive frameworks for virtual design and understanding of novel nanoscale materials with specific and/or emergent properties. This vision is possible through a multi-pronged, holistic, and tight integration with Materials Research Division (MRD) distinctive capabilities in precision experimental synthesis and characterization alongside leadership class computing. Understanding how atomic scale structure, confinement, and quantum mechanical effects impact electronic processes within these nanostructures and across interfaces to enable the design and synthesis of materials with prescribed functional (physio-chemical) properties. Very thin sheets of a material can exhibit greatly enhanced properties such as increased electrical conductivity as compared with the bulk and are well suited for applications in new electronic devices. Our goal is to understand how to design and control the nanoscale organization of macromolecular nanomaterials and their nanocomposites in order to achieve improved structure, properties, and functionality. The iThemba Laboratory for Accelerator-Based Sciences (iThemba LABS) where he studies materials for energy applications. His research interests include bulk and nanoscaled materials for solidstate- physics, and multifunctional metal oxide nanomaterial.
Abstract:
In the present work, we synthesized ZrO2:PbO2 nanorods samples were prepared by solvothermal process and the physiochemical properties of ZrO2:PbO2 nanoparticles were determined by using X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV– vis), Transmission electron microscope (TEM), Energy dispersive X-ray spectrometer (EDX) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated by the degradation of methylene blue (MB) dye under UV and visible light irradiation. The solvothermal made ZrO2 treated PbO2 nanorods showed the highest photocatalytic activity under both UV and visible light irradiation. The addition of the ZrO2:PbO2 resulted in the formation of partial monolayer of ZrO2 doped ZrO2:PbO2 nanorods and an increase of the anatase phase stability. The XPS results reveal that the calcinated ambiance affected the distribution concentration of surface and interface species in ZrO2 and Zr-doped PbO2, such as surface oxygen and Pb3þ sites, thus improving photo catalytic activity.
Bella Mellisani
Gadjah Mada University, Yogyakarta, Indonesia
Title: Characteristics of Colloidal Ag Nanoparticles in Polyvinyl Alcohol with Different Molecular Weight
Biography:
Bella Mellisani completed her undergraduate program in Chemistry at Tanjungpura University. Currently, she is working on her MSc Program in Chemistry at Gadjah Mada University Yogyakarta, Indonesia. She receives scholarships from The Indonesia Endowment Fund for Education, Ministry of the Finance Republic of Indonesia. Her work focuses on the synthesis of functional nanoparticles.
Abstract:
Colloidal Ag nanoparticles are of interest for many researchers due to their vast potential applications. In this work, the colloidal Ag nanoparticles were prepared in the polyvinyl alcohol (PVA) solution as a capping agent using ascorbic acid as reducing agent. PVA with a molecular weight of 13,000-23,000 (PVA-I) and 145,000 (PVA-II) was used. The concentration of silver nitrate and ascorbic acid was set at 3.0 x 10-4 mol L-1 and 6.0 x 10-4 mol L-1, respectively. The reaction between Ag+ ion and ascorbic acid in PVA was performed at 80°C. After 5 min of heating, the solution color changed from colorless to yellow to indicate the formation of silver nanoparticles. The optimum concentration of PVA-I and PVA-II was found to be 1.0% and 0.25%, respectively. The surface plasmon resonance (SPR) absorbance of the colloid in PVA-I has λ-max of 416 nm, with full-width-half-maximum of 94 nm. The SPR absorbance of the colloid in PVA-II has λ-max of 413 nm, with full-width-half-maximum of 73 nm. The colloids are stable for four weeks, which show a decrease in the SPR absorbance by 10.57% in PVA-I and 8.45% in PVA-II. Using PVA-II, the synthesis required a lower concentration than that of using PVA-I. The colloidal Ag nanoparticles in PVA with high molecular weight have smaller particle size than that in PVA with lower molecular weight.
Aline Simo
University of South Africa, South Africa
Title: Gas Sensing Properties of VO2 –Vanadium Dioxide Nanobelts: Strongly Correlated Materials in Low Dimension
Biography:
Aline Simo has completed her PhD at the age of 29 years from Western Cape University and was awarded the l`Oreal Unesco For Women in Science. She is currently doing her postdoctoral studies at UNISA University, College of Graduate Studies. She is working on various V-based systems functional materials and she has bringing new insight regarding the potential sensing application aspect of the vanadium oxide material at room temperature
Abstract:
Porous polycrystalline resistors made of metal oxides are highly demanded as semiconductor gas sensors. The operating at low temperature requires narrow band gap resistive gas sensors amongst which vanadium oxides have been found to be suitable for gas sensing materials. This is due to their ability to be used as catalysts in oxidation reaction and to form different lower oxides stoichiometry of the VO cubic lattice derived from V2O5. Hydrogen (H2) is one of the attractive energy sources to succeed the current carbon based energy, with the highest specific energy content of 141.79 MJ/kg and high risk of explosions while handling its storage and usage. In relation to H2 economy, various 1-D nanomaterials have been investigated as ideal candidates for gas sensing applications. Well established gas sensing materials such as SnO2, ZnO, WO3, have shown higher sensitivity and selectivity efficiency at high temperature resulting in significant power consumption with addition to their complexities in device integration. VO2 oxide nanobelts are demonstrated to be effective hydrogen gas sensors at room temperature with sensitivity as low as 14 ppm. The nanobelts (ultralong belt-like) nanostructures could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides and for building functional devices based on individual nanobelts.
Bertrand Tumbain Sone
University of the Western Cape, South Africa
Title: Biosynthesis of NiO nanoparticles using Callistemon viminali's extracts & their potential for psuedocapacitor applications
Biography:
B.T. holds a PhD in Chemistry from the University of the Western Cape, South Africa. He is currently a DST-NRF Innovatiuon Postdoctoral fellow at the UNESCOUNISA Africa Chair for Nanosciences & Nanotechnology, and is hosted by the Materials Research Dept’t of iThemba LABS. He has published more than 16 papers and proceedings in ISI peer reviewed journals and conference proceedings. His interests lie in the area of gas sensing, electrochromism, energy storage, solar cells.
Abstract:
P-type Bunsenite NiO powders with an average crystallite size of 21 nm (as shown by x-ray diffraction analysis) were produced via biosynthesis and heat treatment, using aqueous extracts from flowers of the plant Callistemon viminalis. SEM showed that the NiO powders consisted of particles with sizes in the 20-35 nm range while XPS confirmed the formation of highly pure NiO. From Raman spectroscopy, strong 1 phonon vibration at 507.4 cm-1and the existence of a broadened 2-phonon band of reduced intensity at 1096 cm-1 confirmed that biosynthesized NiO powders were not only defect-rich/ rich in surface effects but were also nanosized with dimensions less than 100 nm. Using UV-Vis-NIR spectroscopy the optical band gap for a spin coated thin film of NiO obtained by spin coating unto glass the green coloured Ni2+-containing aqueous extract of Callistemon viminalis red flowers, then annealing in air, was calculated to be 3.35 eV. A cyclic voltammetric study of the redox processes in thin films of the NiO nanopowders on Ni showed the redox processes to be quasi-reversible with the films showing good potential for pseudocapacitance. From our calculations the specific capacitance of the NiO thin films on Ni was estimated at 101 F/g, a value close to that reported in the literature. This method demonstrates that the use of natural plant extracts can be a cost-effective and environmentally friendly alternative to preparing Nickel oxide nanoparticles that can be of use in a variety of energy storage applications.
Sanele Nyembe
University of Witwatersrand, South Africa
Title: Sorption of NO, CO and CH4 on Indium Phosphide Nanowires Supported with Molecular Modelling
Biography:
Sanele Nyembe has completed his Msc from University of Witwatersrand, Johannesburg and currently doing his PhD with the same university. He works as a Scientist at Mintek-Nanotechnology Innovation Centre, Research and Development. He has published 2 papers in reputed journals from his PhD work and 1 publication from other projects.
Abstract:
Temperature Programmed Desorption (TPD) is crucial spectroscopic method used to determine thermodynmic and kinetic parameters of desorption processes. Sorption of gases from Group III-V semiconductor nanowires is a fascinating area of nanoscience, because they reveal potential of gas sensing. These nanowires have a potential to be used in various applications such as photonics, electronics including micro and nanoelectromechanical systems (MEMS and NEMS). They have relatively tuneable small direct bandgaps (Indium Phosphide (InP) = 1.34 eV) which makes them suitable for use in optoelectronic devices as well. InP surface in particular, has an interesting electron reach/deficiant active sites that could form part of the gas binding sites. The sorption of gases such as Methane (CH4), Carbon Monoxide (CO) and Nitric Oxide (NO) were studied using TPD. In this study, it was discovered that InP nanowires binds through chermisoption to both CO and NO and binds very weakly through physisorption to CH4. The heat of desorption enthalpies were found to be 140 kJ/mol, 80 kJ/mol and 48 kJ/mol for CO, NO and CH4 respectively. The experimental enthalpies were compared to the theoretical values (binding energies) obtained through molecular modelling. The binding modes of the gases to the surface of InP nanowires were studied by Diffuse Reflectance Infrared Fourie Transorm Spectroscopy (DRIFTS) together with adsorption modelling. This study reveals the nature and strength of interaction between NO, CO, CH4 gas molecules on the surface of InP nanowires and the sorption temperature range.
Nolubabalo Matinise
iThemba LABS-National Research Foundation, South Africa
Title: Facile method on fabrication of mixed phase bimetallic nanocomposite with high activity for electrocatalytic application
Biography:
Nolubabalo Matinise has completed her PhD in 2014 at the University of the Western Cape under electrochemistry in Sensorlab research group. Her PhD research involves sensors and applied electrodynamics of nanomaterials. She is a postdoctoral fellow for two years now at iThemba labs under material research department. Her research interests include morphologically, optical, surface modification and dimensionally controlled synthesis and characterization of nanomaterials, bimetallic, polymers, development of new high efficiency and low cost transitional metal nanoscale catalysts, as well as investigation of the relationships between their structures and properties, and exploring their applications in heterogeneous catalysis, electrochemistry, energy conversion or nanoscale electronic devices.
Abstract:
The research work involves the development of better, inexpensive, reliable, easily and accurate method for the fabrication of novel metal oxide nanoparticles-based nanocomposite materials through green synthetic method. The characterization of the nanostructured nanocomposite materials will use various techniques, including High Resolve Transmission Electron Microscope (HRTEM) technique for the physical property such as morphology, particle size, structure and particle distribution; Fourier transform infrared spectroscopy (FTIR) for the composition and purity of the product; Ultraviolet-vis spectroscopy (UV/Vis spectra) Photoluminescence (PL) analysis for optical studies; X-ray diffraction (XRD) for purity and crystalline structure; Thermal studies by DSC/TGA technique for change phases and weight loss and Electrochemical methods such as cyclic, square wave voltammetry and electrochemical impedance spectroscopy for the evaluating the electrochemical activities. The electrochemical dynamics as a sensor or electrochemical catalyst of the nanostructured crystalline multi-metallic will be studied using cyclic voltammetry and Electrochemical Impedance Spectroscopy (EIS). The development of electrodes is prepared by drop coating the metal oxide nanoparticles-based nanocomposite materials on the surface area of electrode (Glassy carbon/Platinum) electrode for electrochemical application.
Xolile Fuku
University of South Africa, South Africa
Title: Application of punica granatum L functionalised bimetallic nanooxides on PVP with high catalytic activities via facile green process
Biography:
Xolile Fuku is a Chemist and obtained his PhD in 2014 at the University of the Western Cape, SensorLab Research Group. Presently, he doing his Post-doctoral studies at iThemba LABS under UNISA/UNESCO African chair. His research platform is in nanotechnology, material science and electro-analytical chemistry, which focuses on fundamental and applied electrodynamics of materials and sensors.
Abstract:
Bimetallic nano-oxides on polyvinylpyrrolidone will be synthesised by simple and facile green route. The green synthesised nanocomposite will be characterised by different techniques and methods. Detailed structural, compositional, optical, photoelectrochemical and electrochemical properties of the obtained nanomaterials will be analysed by X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), ultraviolet-visible spectroscopy (UV-Vis), impedance spectroscopy (EIS), cyclic voltammetry (CV), galvanostatic charge-discharge (CDG) and FTIR spectroscopy techniques. Ni substrate and boron doped diamond (BDD) will be used as electrochemical transducer for the fabrication of the potential energy storage devices. Furthermore, the nanocomposites will be used as a catalyst and in other applications such as solar absorbers.
Denisha Gounden
University of Kwa Zulu-Natal, South Africa
Title: Iron oxide/phthalocyanine composites for electrochemical detection of heavy metals.
Biography:
Ms.Denisha Gounden has completed her undergraduate (BSc. Biochemistry, Chemistry) and honors (BSc. (Hons) Chemistry) degrees at the University of KwaZulu-Natal (2010-2014). She is currently pursuing her MSc. degree. Her first scientific paper was published in 2015, which was based upon her honors research entitled, the “Impact of spiked concentrations of Cd, Pb, As and Zn in growth medium on elemental uptake of Nasturtium officinale (Watercress)”.
Abstract:
Electrochemistry has been widely recognized as a simple and yet highly efficient method for the fabrication of low cost, portable sensors for onsite detection of heavy metals. This study explores the use of iron oxide nanoparticles incorporated with metallophthalocyanines for the selective detection of heavy metal ions from aqueous solution. The iron oxide nanoparticles (NPs, Fig 1a) were synthesized using a co-precipitation method and later coated with silica via a modified Stober method. The synthesized nanoparticles were characterized using IR, EDX, SEM, TEM, XRD, XPS and Mossbauer spectroscopy. These characterization techniques confirmed NP formation, silica coating and super paramagnetism. Phthalocyanines have been reported to enhance electrochemical sensitivity of numerous electrochemical reactions due to their extensive π-system. The Pcs were synthesized and characterized using IR, UV-vis, MCD and MALDI-TOF. It is expected that the impressive properties of iron oxide nanoparticles coupled with the electro-active Pcs will have a synergistic effect that will enhance the sensitivity of heavy metal detection. The electrochemical performance of this hybrid system towards the selective detection of heavy metals is explored.
Phumlani Tetyana
Mintek Nanotechnology Inovation Centre, South Africa
Title: Aqueous Synthesis of Copper Sulfide Nanoparticles for Biological Applications
Biography:
Phumlani works as a research scientist in the DST/Mintek Nanotechnology Inovation Centre (DST/Mintek NIC), at Mintek. He holds an MSc degree in Physiology and is currently registered for a PhD degree in Chemistry and Nanosciences at the University of Witwatersrand.
Abstract:
Innovation in the field of nanotechnology has shown potential to unlock key advances in the detection, diagnosis, treatment and management of infectious diseases. Nanotechnology has pioneered the miniaturization of structures and materials to a nanometre scale, forming nanostructures that are suitable to explore biological processes. Amongst nanomaterials, quantum dots (QDs) are gaining popularity in biological applications. Quantum dots have been applied in biological assays as fluorescent probes for disease diagnosis in vitro and imaging replacing conventional fluorophores (organic dyes and fluorescent proteins) thereby improving assay sensitivity. Amongst these QDs, Copper Sulfide (CuxS) nanoparticles have been the most widely used nanomaterial since they are non-toxic, inexpensive and stable under ambient conditions. Herein, we report the synthesis of glutathione (GSH) capped copper sulfide quantum dots for use in biological applications. Biocompatible copper sulfide nanoparticles of different shapes and sizes were synthesised in aqueous media using a one pot hydrothermal synthesis route. These nanoparticles were found to be less toxic when tested on mammalian cells in the MTS assay, and therefore qualify for use as targeting agents in biological assays.
Fredrick O. Okumu
Cape Peninsula University of Technology, South Africa
Title: X-ray diffraction and band gap studies of bimetallic silver-platinum nanoparticles
Biography:
Fredrick Okumu is a 31 years old doctoral student at Cape Peninsula University of Technology (CPUT), faculty of applied science and has recently submitted his PhD thesis for examination. He is currently working as student support staff at CPUT as a retention officer. He has published 6 papers in reputed journals.
Abstract:
Core shell bimetallic nanoparticles of Ag-Pt of varying ratios (1:1, 1:3 and 3:1) band gaps were studied using UV-visible spectroscopy (UV) and cyclic voltammetry (CV) and further characterized using X-ray diffraction (XRD) technique. Tauc’s model was employed for optical band gap studies typical of direct band gaps while electrochemical band gap was investigated under CV based on Breda’s equation. Band gap of nanoparticles were found in the range of 3.55 eV to 4.02 eV for optical and 1.45 eV to 1.80 eV for electrochemical measurements. The expansion in each case could be attributed to quantum size effect. Band gap increase in the bimetallic nanoparticles ratios was consistent in both electrochemical and optical results relative to monometallics. The fact that electrochemical band gaps were found to be smaller than the optical band gaps with an average factor difference above 1 was attributed to solvation and electrode surface coverage effects. These band gap values suggest better electroactivity of the nanoparticles. Although the electrochemically determined band gaps were found to be lower than the optical band gap, in most cases values portrayed similar trends. These results depict nanoparticles with band gaps within semiconductor range for most materials. XRD patterns depicted crystallinity in all the synthesized NPs with confirmation of the face centred cubic structure. Comparison of transmission electron microscope (TEM) data showed that the band gaps were nanoparticle size-dependent with an inverse relationship observed and this was attributed to the quantum confinement effect.
Biography:
Chiara Busa’ completed her scientifically oriented secondary school in 2005; she obtained her BSc in 2009 in Chemistry and Master in Chemical Science, graduating in 2012, at university of Florence(IT); She moved to Sweden, where she was consulting in Applied Physics at Chalmers University of Technology(SE); in 2014, she joined Pola Goldberg-Oppenheimer group(Advanced Nano-Materials, Structures and Application) to undertake her PhD in Chemical Engineering at the University of Birmingham(UK).
Abstract:
DNA nanotechnologies had a major development during the last two decades. Their real potential and versatility began to be investigated and understood with the synthesis of a polyhedron-structured DNA molecule. Due to the intrinsic properties of DNA and developments in sequence design, different polyhedral, either in shape and/or dimensions were synthesised. Custom-tailored properties and high yields are characteristic of these structures. In this project, the main work was represented by the disposition, anchoring and imaging of self-annealed DNA polyhedron, with high yield and stability of the molecules. The last step consists in formation a gold layer on top of the pre-annealed DNA polyhedron, in order to build a specifically-patterned gold materials with optical responses. According to previous studies, specific strands of DNA sequence were designed, to anneal and form a geometric 3D tetrahedron, with >90% yield. The anchoring of the DNA structures was carried out on TEM carbon grids, where the structures where demonstrated to firmly immobilise on the surface. Hence, the gold layer deposition was carried out by electroplating, due to the conductive nature of the TEM grid employed. AFM and TEM are the predominant techniques carried out for characterizing the structures and their disposition on the substrates in each stage of this work.
Aruna Reddy
The University of Manchester, UK
Title: Detection of aqueous uranyl(VI) species using rare-earth upconversion nanophosphors
Biography:
Aruna completed her MSc in Manchester working on a project titled “Synthesis of organelle-specific inhibitors of Deubiquitinating enzymes” in 2013. She is currently a BBSRC funded PhD student on the Doctoral Training Partnership also at the University of Manchester under the supervision of Dr Louise Natrajan and Dr Sam Hay. Aruna has also spent time at the National Nuclear Laboratory for several months working on separation of radionuclides.
Abstract:
Upconverting nanophosphors (UCNPs) are typically composed of an inorganic lattice doped with luminescent lanthanide ions and demonstrate the ability to convert long-wavelength excitation in the near-infrared (with wavelengths of typically 800-1000 nm) into higher energy visible luminescence. Such materials display several advantages in analytical applications, in comparison to other fluorophores, including low autofluorescence and scattering of excitation radiation, reducing background noise. Lanthanides display multiple very specific emission bands allowing careful tuning of the emission profile of the UCNPs. These properties make then suitable candidates as the donor species in luminescence resonance energy transfer (LRET) in chemical sensors and biosensors. This project details the design of a chemical sensor based on Gd4O2S:Yb,Tm and Gd4O2S:Yb,Er UCNPs. A proof of principle technique for the detection of uranyl(VI) species in aqueous solutions has been developed. Luminescence resonance energy transfer efficiency is used to sense these species. Tm3+ and Er3+ doped upconversion nanophosphors exhibit emission bands at 475 nm and 410 nm respectively, which can be monitored by ratiometric analysis, relative to other emission bands. Recent work consists of improving the sensitivity of the current system to detect lower concentration of uranyl(VI) species.
Chloë Oakland
The University of Manchester, UK
Title: Biosensing Applications of Upconverting Lanthanide Nanophosphors
Biography:
Chloë is a final year PhD student of the North West Nanoscience Doctoral Training Centre (NoWNano DTC) at The University of Manchester, UK. She currently has two publications and was awarded the TA Students Application Award in 2014. Chloë also has industrial experience working in pharmaceutical R&D on the development of inhaled therapeutics to reduce rejection in lung transplant patients and monitoring drug manufacture for the Indian sites of a large generic pharmaceutical company.
Abstract:
Rare-earth upconversion nanophosphors (UCNPs) are rapidly emerging as an important class of nanoparticles with potential uses in bioimaging, biosensing and therapeutics. When UCNPs are excited with near infra-red (NIR) light they exhibit efficient photoluminescence in the visible spectrum due to photon upconversion (UC). Their emission spectrum can be tuned by doping the UCNPs with various lanthanides, allowing for multiple sharp, line-like emission bands, long emissive lifetimes and, as a consequence of their UC, no autofluorescence. These properties make UCNPs particularly promising as biosensing probes. The aim of this project is to develop sensitive and selective UCNP-based biosensing systems. Preliminary work involved investigation of the interaction between the flavin-containing enzyme pentaerythritol tetranitrate reductase (PETNR) and the UCNPs. Promising results have been obtained from this system; UCNPs are able to detect the presence of FMN, the intrinsic cofactor of PETNR, through energy transfer. Using this energy transfer process enzyme turnover can be indirectly monitored by ratiometric methods due to the multiple bands in the UCNP emission spectra. Work is now focused on improving the sensitivity of this UCNP-enzyme biosensing system.
Siek-Ting Yong
Monash University, Malaysia
Title: Permeation of Hydrogen atoms through Dense Hollow Fiber
Biography:
Dr. Siek-Ting Yong obtained her Ph.D. degree in Chemical Engineering from the National University of Singapore. She is a senior lecturer in Monash University Malaysia Campus. Her research interests include fuel reforming, direct carbon fuel cell, carbon capture, and membrane separation.
Abstract:
It is crucial to achieve high purity of Hydrogen for the use in renewable energy industry. Purification of Hydrogen using dense hollow fiber is one of the common ways employed. The transport mechanism of Hydrogen from one side of the membrane to the other side involves a series of sequntial steps. It started with the adsorption and dissociation of Hydrogen molecules, then absorption and diffusion of protons, followed by recombination and desorption of Hydrogen molecules. The dissociation of Hydrogen molecules on the membrane surface plays the most critical role in the overall trasnport mechanism. In this work, a novel post-treatment method using aluminium nitrate solution was developed. The objective is to achive high Hydrogen permeability and ideal selectiviy in parallel by improving the morphology of hollow fiber via mobility control of polymer chain. Morphologies analyses including FTIR-ATR, DSC and EDX were carried out and the mechanism of chemical surface modification was proposed.
Devika Chithrani
Ryerson University,Toronto
Title: Optimization of Bio-Nano Interface for Improved outcome in Nano Medicine
Time : 12:10 - 12:30
Biography:
Devika chitrani has completed his PhD from University of Toronto. She was avarded the faculty gold medal and gold medal for physics at her BSc convocation. She is the director of Nanoscience and Technology Development Laboratory at Ryerson University. He has published more than 30 papers in reputed journals in few years time and has been serving as an editorial board member for six Nano journals. Her work was featured on the cover of radiation research and Nan-Micro letters. Her group is very dynamic and published 14 papers and 3 book chapters in last two years alone. Her publications has received over 4000 citations in the last few years.
Abstract:
The interface between nanotechnology and biology needs to be well understood for improved outcome in medical applications. In other words, we need to know the interaction of nanoparticles with individual cells and tissue for improved outcome in diagnosis, imaging and therapeutic techniques. Among other nanoparticles, gold nanoparticles (GNPs) are emerging as a novel tool to improve existing cancer therapeutics. GNPs are being used as radiation dose enhancers in radiation therapy and as well as an anticancer drug carrier in chemotherapy. However the success of GNP-based therapeutics depends on their ability to penetrate and distribute homogenously in tumor tissue. In this work, multicellular layers (MCLs) were grown to model the post-vascular tumor environment. GNPs of 20 nm and 50 nm diameters were used to elucidate the effects of size on the GNP penetration and distribution dynamics. Though the GNPs were able to penetrate into the tumor tissue, their penetration was inversely proportional to the GNP size. Similar to in vivo tissue, the MCLs exhibited a much more extensive extracellular matrix (ECM) than monolayer cell cultures. This increased ECM created a barrier for NP transport. Smaller NPs penetrated better compared to larger NPs. This model tissue structures are better tools to optimize NP transport through tissue before using them in animal models. This work highlights the importance of both the improved tissue model provided by MCLs as well as the importance of GNP functionalization in cancer therapeutics. A multifunctional platform based on gold nanostructures holds an array of promising directions for cancer research.
Mike S Scurrell
University of South Africa, SA
Title: Thoughts on the use of gold-based catalysts in environmental protection catalysis
Biography:
Mike Scurrell has worked extensively in catalysis for over 40 years and has published some 170 papers in various areas. He is Emeritus Professor of Chemistry at the University of the Witwatersrand in Johannesburg and is also Research Professor at the University of South Africa in Johannesburg in South Africa. He held previous positions at the University of Edinburgh, Scotland, the Technical University of Denmark, the CSIR, South Africa and at Anglo American Research Laboratories. His current interests are in improving heterogeneous catalysts through the use of innovative approaches in nanosynthesis.
Abstract:
Gold catalysts for CO oxidation have been very well studied, particularly using titania as a support. Small nanoparticles of gold are implicated in the catalysis and support effects must also be present because there is a marked activity dependence of the support. Only gold-perovskites appear to show activity essentially identical to that of Au/titania, depending on the nature of the A and B elements present in the Au/ABO3 structure. The low temperature activity of gold for the oxidation of hydrocarbons has also been demonstrated and it has been suggested that gold may well form the basis for active autoemission control catalysts for use at low temperatures, under cold start conditions. The economics of using gold rather than the platinum group elements are also considered to be attractive. Gold anions are associated with the defect sites present in titania, but undergo spontaneous partial reduction so that a variety of oxidation states may coexist in solid catalysts. The +1 oxidation state appears to correlate best with CO oxidation activity but a role for zerovalent gold may also be contemplated. It seems possible to thrift gold by the judicious use of cyanide extraction though this reaction is not simple. High temperature applications of gold catalysts such as autoemission control catalysts have been discussed but the simultaneous use of platinum complicates the understanding of just which entities are responsible for catalysis. Nanogold particle growth must be stopped ar, at least controlled. Recently the4 use of nanoaligned rutile rods as a support for gold appears to offer a very convenient method for stabilizing nanogold. These catalysts show very limited growth of gold up to about 800 °C and offer a very real chance of designing gold only-based catalysis for emission control. The oxidation of CO remains very high even after exposure of the solids to high temperatures. The activity of gold for hydrocarbon oxidation is also well known, but the behaviour of gold in effecting NOx removal, though claimed, is less well studied. Applications in diesel exhaust systems, where device temperatures are likely to be lower are probably more immediately realizable than 3-way systems for gasoline emission control applications.
Abongile Ndamase
Tshwane University of Technology, SA
Title: Linear polyamidoamine Conjugate Containing Pamidronate and Platinum Drug: Characterization and In Vitro Cytotoxicity
Biography:
Miss Abongile Ndamase is currently studying masters in polymer technology at Tshwane University of technology. She has a BTech Biotechnology that she obtained from the Vaal University of Technology. In 2014 she did an internship and counsel of scientific and industrial research (CSIR), that is when she became a co-author to a publication.
Abstract:
Drug delivery, using polymers as carriers, is one of the important areas of research that scientists are uncovering due to the belief that they help improve drug efficacy. Chemotherapy is an effective treatment for breast cancer, but due to the side effects that result from the drug not only targeting the cancerous cells but also the quick dividing cells of the system, patients become extremely sick before they could get cured. In this paper, we investigate the hypothesis that pamidronate and platinum complexes could be conjugated with linear poly(amidoamine)s (PAMAM) in order to improve drug efficacy and this is a possibility because of the physicochemical properties of PAMAM such as: they are pH-responsive, precise direct targeting of the drug to the infected cells, meaning that only the infected cells would be treated. The conjugates were synthesised by Michael-addition process and characterised using SEM; TEM; AFM; FTIR and EDS in order to determine the occurrence of conjugation. In-vitro viability assay was done using HeLa and MCF-7 cell lines. EDS and FTIR confirmed the conjugation of the drugs to the polymer and viability assay confirmed that the conjugates are not toxic to the cells. Therefore, the results obtained from this experiment prove that there is potential for PAMAM to be used as drug delivery for cancer cells, however further characterisation and in-vitro tests would need to be conducted before further steps are taken.
- Track 2: Nanoscience & Technology, Track 3: Nano Medicine, Track 6: Nanotechnology in Energy Systems, Track 7: Emerging Areas of Nanotechnology, Track 8: Nano Applications
Chair
Zhypargul Abdullaeva
Kumamoto University, Japan
Co-Chair
Amr Tayel
The American University in Cairo, Egypt
Session Introduction
Zhypargul Abdullaeva
Kumamoto University, Japan
Title: Solvothermal synthesis of Graphene, carbon-based Nanoparticles, Characterization, study their properties and Applications
Biography:
Zhypargul Abdullaeva is Assistant Professor in the Department of Materials Science and Engineering at Kumamoto University in Japan. She has graduated her PhD degree from the Kumamoto University in Japan. Her research is focused on syntheses of carbon, graphene nanomaterials and their characterizations, and study of their properties, including biomedical, cancer treatment, photocatalytical, optical, applications, etc. She has authored number of scientific publications and has received Gold, Silver and Bronze diploma awards in the Chemistry Olympiads. She is also a member of the Japanese Ceramics Society, American Vacuum Society, and Materials Research Society, European Society of Biomaterials.
Abstract:
Recent progress in syntheses and characterizations of nano-sized materials are in their high stages, actively facilitating new and up-to date developments of equipment and technique for manufacturing and precision process. Our work presents synthesis of graphene, carbon-like and other metallic nanomaterials by solvothermal synthesis method. Synthesis carried out inside stainless steel autoclave, with applying of temperature from 1-300 °C, and pressure between 1 and 20 Mpa. XRD analyses, TEM, HRTEM observations, FT-IR, Raman spectoscopical characterizations were used to determine phase, composition, and size parameters of as-synthesized nanomaterials. Variable synthesis conditions (T/°C, pressure/MPa, time/hours, days), and types of starting materials (initial compound, solvent liquid, and surfactant) allow us to achieve unique phase and structure nanomaterials. Currently, graphenelike compound by solvothermal synthesis was synthesized and analyzed by HRTEM which revealed several-layer graphene sheets with hexagonal comb structure. Raman spectra collected at the room temperature, using the He-Ne laser (633 nm), from 100 to 3000 cm-1 of Raman shift, detected second ordered 2D band at around 2700 cm-1. In addition, influence of various surfactants to the solvothermal synthesis process of graphene-like nanomaterials is studied and currently analyzing to find the optimal and appropriate synthesis conditions.
Martin Falk
Institute of Biophysics of ASCR, Czech Republic
Title: The mechanism of metal nanoparticle-mediated radiosensitization of tumor cells may be independent of DNA damage amplification and DNA repair inhibition
Biography:
Martin Falk has completed his Ph.D from Masaryk University in Brno, CR. He is the leader of the Department of Cell Biology and Radiobiology at the Institute of Biophysics of the Czech Academy of Sciences (Brno, CR). He participated in more than 30 papers that concern the role of chromatin structure in regulation of cellular processes. Other research interests include DNA damage and repair, carcinogenesis, tumor cells radio-sensitization, and radiobiology.
Abstract:
Selective targeting of radiation effects to tumors represents a fundamental challenge in radiotherapy. Metal nanoparticles, such as gadolinium, gold, or platinum nanoparticles are preferentially internalized by tumor cells and have been recognized to locally amplify the radiation dose upon irradiation. Hence, nanoparticles delivered in tumor cells might increase tumor-specificity and efficiency of radiotherapy at the same time. The physical mechanisms related to the radiation dose amplification by nanoparticles have been already well described; however, cellular structures targeted by nanoparticles remain unknown. The DNA molecule is the most sensitive and critical cell structure in the cell concerning the effects of ionizing radiation. Hence, a crucial question remains open of whether a damage to the nucleus is necessary for the radiosensitization exerted by gadolinium and other nanoparticles.In this work, we studied the effect of 3 nm gadolinium based nanoparticles (GdBNs) on the induction and repair of DNA double-strand breaks (DSBs) in the nuclear DNA of U87 tumor cells irradiated with γ-rays. For this purpose, we used currently the most sensitive method of DSB detection based on high-resolution confocal fluorescence microscopy coupled with immunodetection of two independent DSB markers, γH2AX and 53BP1. Equivalent data for Au and Pt nanoparticles are just being analyzed. Our experiments brought about quite surprising results. In the conditions where GdBNs amplify the radiation effects, they remain localized in the cytoplasm and their influence on DSB induction and repair is only insignificant. This suggests that the radiosensitization mediated by GdBNs and potentially other nanoparticles (of defined parameters) is a cytoplasmic event that is independent of the nuclear DNA breakage (a phenomenon commonly accepted as the explanation of biological radiation effects). Based on recognized intracellular localization of nanoparticles studied, we hypothesize about possible non-DNA targets for (some) nanoparticles.
Young Soo Kang
Sogang University, South Korea
Title: Artificial Photosynthesis: Solar Light Driven Selective Methanol Production by CO2 Reduction
Biography:
Young Soo Kang has completed his PhD from University of Houston and Post-doctoral studies from University of California at Berkeley and Stanford University. He is the Deputy Director of Korea Center for Artificial Photosynthesis, a premier research center of Korea. He has published more than 250 papers in reputed journals .
Abstract:
Selective production of methanol via artificial photosynthesis (AP) is new paradigm of energy source to solve the greenhouse effect. Since the first concept of AP suggested in 1912, realization of AP is going through tough time in adjusting several key parameters. The key parameters for one-pot CO2 reduction reaction to methanol are band gap engineering, multi-electron production and shuttling from photoanode to cathode, pH and polarity of reaction media and well-tuned reduction potential for CO2 reduction. Herein, we suggest well-tuned photoelectrochemical system of AP for alcohol production from CO2. Facet-engineered photoanode materials are used for multi-electron production by solar energy. Cathode material complexes are used for shuttling multi-electrons to CO2 with appropriate reduction potential, leading one-pot reaction of CO2 to alcohol reduction. Also, we will introduce the complex structure of cathode materials, reducing thermo-dynamical energies for rate determinant step for CO2 reduction, which is first electron transport to CO2 , making AP much easier than before.
Kelgenbaeva Zhazgul
Kumamoto University, Japan
Title: Bimetallic nanoparticles by solvothermal synthesis
Biography:
Kelgenbaeva Zhazgul has studied her Bachelor’s (BS) in Arabayev Kyrgyz State University (Bishkek, Kyrgyzstan) and Post-graduation in National Academy of Sciences of the Kyrgyz Republic. She completed her PhD from the Department of New Frontier Sciences, Kumamoto University, in 2015 (Japan). She is a Skills Assistant in Institute of Pulsed Power Sciences of Kumamoto University since April 2015 and a Post-doctoral Researcher in Department of New Frontier Sciences since March 2016. She has published more than 5 papers in reputed journals in two languages: English and Russian (Newsletter of National Academy of Sciences of the KR).
Abstract:
Bimetallic nanoparticles have recently attracted much attention, because of their unique catalytic, electronic, optical, magnetic and other novel dual (depending on metals) properties and wide range of possible applications. The bimetallic nanoparticles can be generally divided into two types in the structure: The alloyed and the core/shell structure bimetallic nanoparticles. In this study, we present Au-Fe/Au-Fe3O4 nanoparticles prepared by solvothermal method. The solvothermal process involves the use of a solvent under moderate to high pressure (up to 20 MPa) and temperature (up to 300 °C) that facilitates the interaction of precursors during synthesis. Fe nanoparticles with size range of 5-10 nm were synthesized using pulsed plasma in liquid (PPL) method. The Fe nanoparticles along with HAuCl4 (1.0 mM concentrated solvent) and Trisodium Citrate Didydrate (TCD: C6H5Na3O7*2H2O) were mixed and the solution was heated up to 150 °C for 2 hours to prepare Au-Fe bimetallic nanoparticles. Fe nanoparticles by PPL were served as the core and HAuCl4 as Au source-shell, respectively. The TCD served as reducing agent for Au nanoparticles. Finally, obtained Au-Fe nanoparticles by solvothermal synthesis were characterized via XRD, TEM, EDS, UV-Vis Spectroscopy and Vibrating Sample Magnetometer Analysis.
Genene Tessema Mola
University of KwaZulu-Natal, South Africa
Title: Effect of solvent additives in nano-scale morphology of thin film organic solar cell
Biography:
Genene Tessema Mola has completed his PhD in 2003 from University of Bonn, Germany. Following his Ph.D degree, he joined Addis Ababa University (AAU) as an Asistant Professor of Physics and currently serving as an Associate Professor of Physics at the University of KwaZulu-Natal. He served as director of Material Science Program at AAU. He has published more than 30 papers in reputed journals and has been serving as reviewer and an editorial board member of reputable journals.
Abstract:
Polymer-fullerene based thin film organic solar cells (TFOSC) composed of poly(3-hexylthiophene (P3HT) donor and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) electron acceptor are investigated with and without different processing additives such as: 1,8-diiodooctane (DIO), 1-chloronaphthalene (CN) and dimethyl sulfoxide (DMSO). The effect of these solvents on device performance has been investigated and discussed in terms of changes in optical, electrical and microstructural properties of the photoactive films. Among the additives used in this study DIO has shown remarkable effect on preventing the formation of defect related clusters in the medium and assists the crystallization of the polymer chain leading to the best device performance in the investigation. The nanoscale structures of the films produced with DMSO showed the presence of large concentration of defect clusters resulting in poor performance. Various results of TFOSC devices with and without solvent additives are compared and thoroughly discussed.
Biography:
Dr Sharifpur is a senior lecturers in the Department of Mechanical and Aeronautical Engineering at University of Pretoria (UP) as well as the establisher and responsible for Nanofluids Research Laboratory. He received a BE (Mechanical Engineering) degree from Shiraz University in Iran (one of the top 5 universities out of 2390 universities in Iran, which choosing the top students from national entrance exam). After that He completed a ME degree in Nuclear Engineering, and then received a full scholarship for PhD study from Eastern Mediterranean University. He was the only postgraduate student who received four out of four for the cumulative grade point average (CGPA) when he received his PhD.
Abstract:
Nanofluids which are new heat transfer fluids (consist of nanoparticles and a conventional heat transfer fluid) have shown some new behaviors in thermal fluid systems. First, their effective thermal conductivity and heat capacity of them can be much more than those of the conductivity and heat capacity of the conventional heat transfer fluids. Secondly, magneto-rheological nanofluids (MRNF) can control the viscosity and heat transfer when they are in a proper magnetic field. On the negative side and in general, nanofluids have shown more effective viscosity in comparison to the base fluids. The idea is to find the optimum way to prepare them as well as the optimum range for each nanofluid to provide the maximum heat transfer performance. Consequently, they can significantly reduce the size and materials in the heat transfer applications. Therefore, investigation into the nanoparticles and nanofluid is important regarding material and energy management as well as environment issues. This presentation concerns on different issues and the opportunity of research on the lack of information in nanofluids area to be involved in different industrial applications.
Mesfin Abayneh Kebede
The Council for Scientific and Industrial Research(CSIR), South Africa
Title: Nanostructured LiMn2O4 cathode materials for efficient lithium ion battery energy storage systems
Biography:
Mesfin Kebede has completed his PhD in 2009 in Materials Science and Enginering from Inha University South Korea and postdoctoral studies from UFS & CSIR in South Africa. He is currently a senior researcher at CSIR. He has been studying and researching nanostructured materials properties and applications as electrodes for lithium ion battery, gas senosor, luminescent and photoluminescence, photocatalysis for almost a decade. He has authored 2 book chapters and more than 35 papers in reputed journals and has been serving as reviewer for several journals and he also serves as editorial board member.
Abstract:
Nanowire/nanorod architectured electrode(cathode & anode) materials for lithium ion battery have shown significant enhanced electrochemical performance. Lithium ion battery (LIB) has started to penetrate into power sources for electric vehicles and electric energy storage as the need for clean and renewable energy reaches climax. To fully meet the target of using LIBs for electric vehicle suitable electrode materials with high energy and high power density have to be achieved. To date numerous cathode and anode materials have been developed which can deliver high energy and high power density. One of them is high voltage LiMn2O4 can perfectly suit with this purpose, however it suffer sever capacity fading which hinders it to meet the target. Interestingly, the use of nano-architecturing of electrode materials (both cathode and anode) has shown a very promising result to sustain the capacity of the materials with significantly minimized fading. Bulk LiMn2O4 cathode materials are characterised by capacity fading in maintaining only about less than 50% of their initial capacity after 100cycles. By synthesizing nanowire LiMn2O4 their capacity retention increases significantly to about 85% after 100cycles. In our laboratory we sysnthesized LiMn2O4 nanorod cathodes from South African manganese precursor source and they retained 95% after 100cycles. In this talk the advancement of nanostructured cathode and anode materials for LIBs application will be reviewed and our contribution in this regard will also be presented.
Amr Mohamed Tayel
The American University in Cairo, Egypt
Title: TiO2-Graphene Oxide (GO) Nanocomposites: Synthesis, Environmental Applications and Surface Characterization using Perichromism
Biography:
Amr M. Tayel has completetd his BSc in pharmaceutical science followed by MSc in chemistry from The American University in Cairo (AUC) in 2015. His MSc thesis focused on surface characterization of nanaocomposite photocatalysts. He published one paper in the Journal of Applied Polymer Science. He is an assiociate member of the royal society of chemistry (AMRSC). He is currently a teaching assistant at The American University in Cairo (AUC), chemistry department.
Abstract:
TiO2-graphene oxide (GO) nanocomposites were successfully synthesized using a simple mixing and sonication sol-gel method with varying the rate of hydrolysis of the TiO2 precursor. The average particle sizes of the nanocomposites were 436 ±59 nm and 251 ±32 nm for the samples denoted TL and TS which corresponds to large particle size TiO2 and small particle size TiO2, respectively. The photocatalytic activity of the as-prepared TiO2-GO nanocomposites for methylene blue (MB) degradation was investigated under UV (λ=365 nm) light irradiation. The results showed that TiO2-GO nanocomposites have significantly higher photocatalytic activity than blank TiO2 (no GO). The increase in the photocatalytic activity of the samples was dependent on a number of factors such as surface acidity, surface area and the change in band gap energy. The surface acidity was measured using perichromic dyes and NH3- TPD; both measurements are independent. The increase in overall surface acidity after the GO addition was mostly attributed to Brønsted acidity as Lewis acidity was generally lower than the blank in most samples. However, possible stacking of GO at higher concentrations resulted in the decrease in overall acidity with the increase in GO contents. Surface polarity and polarizability were investigated using perichromic dyes to study their impact on the photocatalytic activity. Other surface properties were evaluated using BET, DRS-UV, FTIR, Raman and XRD. This study provides new insights on the surface characterization of high-performance photocatalysts used in wastewater treatment, correlating these surface properties and photocatalytic activity.
Saleh Khamlich
iThemba LABS-National Research Foundation,South Africa
Title: High perfermence supercapacitor based on 3D graphene nanocomposite
Biography:
Dr S. Khamlich is a native of Morocco/North Africa. He is a scientific researcher at iThemba LABS-National Research Foundation, Western Cape, South Africa. He holds a Doctor of Technology (DTech) degree in chemistry from Tshwane University of Technology (TUT). Saleh has about 06 years of experience in the multidisciplinary field of nano science and nanotechnology with focus on energy storage applications and solar energy conversion/modulation.
Abstract:
Three-dimensional (3D) graphene-based nano composites have attracted significant attention for energy storage and conversion applications. In this study, Simonkolleite nano platelets (SMNPs) were deposited on 3D nickel foam-graphene (NiF-G) by a rapid microwave-assisted hydrothermal method to form NiF-G/SMNPs nano composite electrode material. Field emission scanning electron microscope (FE-SEM) of the NiF-G/SMNPs electrode revealed that the SMNPs were evenly distributed on the surface of NiF-G and interlaced with each other, resulting in a higher electrochemical performance compared to NiF-G and NiF/SMNPs. Utilizing this composite material, a super capacitor with a specific capacitance of 836 F g-1 at a current density of 1 A g-1 has been achieved.
Chloë Oakland
The University of Manchester, UK
Title: Biosensing Applications of Upconverting Lanthanide Nanophosphors
Biography:
Chloë Oakland is a final year PhD student of the North West Nanoscience Doctoral Training Centre (NoWNano DTC) at The University of Manchester, UK. She currently has two publications and was awarded the TA Students Application Award in 2014. She also has industrial experience working in pharmaceutical R&D on the development of inhaled therapeutics to reduce rejection in lung transplant patients and monitoring drug manufacture for the Indian sites of a large generic pharmaceutical company.
Abstract:
Rare-earth upconversion nanophosphors (UCNPs) are rapidly emerging as an important class of nanoparticles with potential uses in bioimaging, biosensing and therapeutics. When UCNPs are excited with near infra-red (NIR) light, they exhibit efficient photoluminescence in the visible spectrum due to photon upconversion (UC). Their emission spectrum can be tuned by doping the UCNPs with various lanthanides, allowing for multiple sharp, line-like emission bands, long emissive lifetimes and, as a consequence of their UC, no autofluorescence. These properties make UCNPs particularly promising as biosensing probes. The aim of this project is to develop sensitive and selective UCNP-based biosensing systems. Preliminary work involved investigation of the interaction between the flavin-containing enzyme pentaerythritol tetranitrate reductase (PETNR) and the UCNPs. Promising results have been obtained from this system; UCNPs are able to detect the presence of FMN, the intrinsic cofactor of PETNR, through energy transfer. Using this energy transfer process, enzyme turnover can be indirectly monitored by ratiometric methods due to the multiple bands in the UCNP emission spectra. Work is now focused on improving the sensitivity of this UCNP-enzyme biosensing system.
Aruna Reddy
The University of Manchester, UK
Title: Detection of aqueous uranyl (VI) species using rare-earth upconversion nanophosphors
Biography:
Aruna Reddy completed her MSc in Manchester working on a project titled, “Synthesis of organelle-specific inhibitors of deubiquitinating enzymes” in 2013. She is currently a BBSRC funded PhD student on the Doctoral Training Partnership also at the University of Manchester under the supervision of Dr. Louise Natrajan and Dr. Sam Hay. She has also spent time at the National Nuclear Laboratory for several months working on separation of radionuclides.
Abstract:
Upconverting nanophosphors (UCNPs) are typically composed of an inorganic lattice doped with luminescent lanthanide ions and demonstrate the ability to convert long-wavelength excitation in the near-infrared (with wavelengths of typically 800-1000 nm) into higher energy visible luminescence. Such materials display several advantages in analytical applications, in comparison to other fluorophores, including low autofluorescence and scattering of excitation radiation, reducing background noise. Lanthanides display multiple very specific emission bands allowing careful tuning of the emission profile of the UCNPs. These properties make them suitable candidates as the donor species in luminescence resonance energy transfer (LRET) in chemical sensors and biosensors. This project details the design of a chemical sensor based on Gd4O2S:Yb,Tm and Gd4O2S:Yb,Er UCNPs. A proof of principle technique for the detection of uranyl(VI) species in aqueous solutions has been developed. Luminescence resonance energy transfer efficiency is used to sense these species. Tm3+ and Er3+ doped upconversion nanophosphors exhibit emission bands at 475 nm and 410 nm respectively, which can be monitored by ratiometric analysis, relative to other emission bands. Recent work consists of improving the sensitivity of the current system to detect lower concentration of uranyl(VI) species.
Juliet Sackey
University of South Africa, South Africa
Title: Order-disorder on the nanostructures on the ocellus of the Caligo memnon (C& R elder[1867]) butterfly
Biography:
Juliet Sackey, 31 years old is pursing PhD studies in Physics with the University South Africa. She is the recipient of the award from the Organization for Women in Science for the Developing World, (OWSD), and the African Development Bank award to read theoretical Physics with the African University of Science and Technology (AUST). Her current research is focused on studying the morphological structures and the optical interpretations in the wings of butterflies for sustainable renewable energy and nanophotonics applications. She has presented several talks in both local and international conferences. She has also published many research articles in peer reviewed journals.
Abstract:
The Caligomemnon butterfly has on its ventral under side false ‘eyespot’ (ocellus). On the inner ring of the ocellus are wing scales of black colour. In our quest to unravel the usefulness of this selective solar absorber-like material, the nanostructures on that section of the wing scale were investigated with various techniques. As evident from the scanning electron microscopy images (SEM), the wing scales on the black section contain ridges and lamellae, which show disorder in their shapes and positions. We have analysed and quantify the type of such order-disorder using direct measurement; statistical approach and Fourier transform methods. Based on the autocorrelation of the SEM image and the Hosemann function, an algorithm to compute the line cuts of the order-disorder was developed. The line cuts provided the average values of periodicity, which were used to calculate the porosity in the wing scale. The porosity was found to be the origin of the antireflection property of the black section bio mimicking as selective solar absorber material.
Abongile Ndamase
Tshwane University of Technology, South Africa
Title: Linear polyamidoamine Conjugate Containing Pamidronate and Platinum Drug: Characterization and In Vitro Cytotoxicity
Biography:
Abongile Ndamase is currently studying Master’s in Polymer Technology at Tshwane University of Technology. She has a BTech Biotechnology that she obtained from Vaal University of Technology. In 2014, she did an internship in Counsel of Scientific and Industrial Research (CSIR), that is when she became a co-author to a publication.
Abstract:
Drug delivery, using polymers as carriers, is one of the important areas of research that scientists are uncovering due to the belief that they help improve drug efficacy. Chemotherapy is an effective treatment for breast cancer, but due to the side effects that result from the drug not only targeting the cancerous cells but also the quick dividing cells of the system, patients become extremely sick before they could get cured. In this paper, we investigate the hypothesis that pamidronate and platinum complexes could be conjugated with linear poly(amidoamine)s (PAMAM) in order to improve drug efficacy and this is a possibility because of the physicochemical properties of PAMAM such as: They are pH-responsive, precise direct targeting of the drug to the infected cells, meaning that only the infected cells would be treated. The conjugates were synthesised by Michael-addition process and characterised using SEM; TEM; AFM; FTIR and EDS in order to determine the occurrence of conjugation. In-vitro viability assay was done using HeLa and MCF-7 cell lines. EDS and FTIR confirmed the conjugation of the drugs to the polymer and viability assay confirmed that the conjugates are not toxic to the cells. Therefore, the results obtained from this experiment prove that there is potential for PAMAM to be used as drug delivery for cancer cells, however further characterisation and in-vitro tests would need to be conducted before further steps are taken.
Lebogang Kotsedi
University of South Africa, South Africa
Title: Surface modification and oxidation of vanadium thin film using femtosecond laser
Biography:
Lebogang Kotsedi is a National Research Foundation (South Africa) research career award grant holder. He is a research fellow of the UNESCO-UNISA Africa Chair In Nanoscience and Nanotechnlogy and also memeber of the NanoAfnet network. He has a passion for photonics based research, he has recently delved in research space of photonics for sustainable energy and surface modification of transition metals using ultrafast laser. His research seeks to address and find sustainable solution to the the national stragitic research areas and other key focus area as outlines by the department of Science and Techology and the renewable energy road map of South Africa.
Abstract:
A glass substrate vacuum coated with a thin film of vanadium metal with the thickness of 500 nm was treated with a femtosecond laser. The laser was pulsing at a fundamental wavelength of 1050 nm and the repetition rate of 500 kHz, the spot size of the laser on the sample was calculated to be 45 μm. The vanadium coating was then treated with various laser fluences, this resulted in the colouration and surface modification of the sample. From the UV-VIS-NIR study the is an evidence of the formation of the vanadium oxide on the surface of the vanadium thin film, furthermore x-ray diffraction patterns of the samples shows that the microstructure of the film has changed and there are new diffraction peaks emerging that point to the oxidation of the film. The High-Resolution Scanning Electron Microscope of the sample clearly shows the evolution of the morphology of the samples due to laser treatment.