5^th International Conference and Exhibition on Polymer Chemistry August 27-28, 2018 Toronto, Ontario, Canada

Biography:

Thi-Thanh-Tam Nguyen has received her PhD in Organic Synthesis and Material-Polymer Chemistry in 2009 at the University of Strasbourg with Dr. Philippe Mesini. After two years working as postdoctoral fellow at Max-Planck Institute for Polymer research (MPIP, Mainz, Germany) in the group of Prof. K. Mullen about the design and the synthesis of photoresponsive polyphenylene dendrimers, she joined Dr. A. Wagner to work in the synthesis of bioactive molecules at the Faculty of Pharmacy in Strasbourg and then worked as temporary assistant professor at the Ecole Normale Superieure (ENS de Lyon) with Dr. Cyrille Monnereau. In 2015, she was appointed as the lecturer in the University Paris-Est Creteil and currently works in the group of Dr. D. Grande. Her main research interest is about the synthesis and the characterization of polyelectrolyte/thermosetting polymer-based materials with controlled morphology and functionality for miscellaneous applications 

Abstract:

The past few decades have witnessed a rapid development of polyelectrolyte-based materials in different fields, such as cosmetic,¹ concrete and cement formulation (superplasticizer),² water treatment (membrane),³ drug delivery,⁴ tissue engineering,⁵ and surface coating, especially via the formation of Layer-by-Layer (LbL) polyelectrolyte films.^6,7 Advances in this field impose challenges on the development of functionalized polyelectrolytes (PEs).^{8, 9}

In this presentation, a general approach to side-chain allylfunctionalization of three different polyelectrolytes (PEs), namely poly(allylamine) hydrochloride (PAH.HCl), branched polyethyleneimine (PEI) and poly(sodium 4-styrene sulfonate) (PSS), currently developed in our laboratory, will be presented.¹⁰ The application of the resulting functional polyelectrolytes (PSS-ene, PAH-ene and PEI-ene) in the buildup of LbL films with enhanced stability under extreme conditions of pH and high ionic strength will also be discussed. Such stability is achieved thanks to the presence of allyl groups not only on PEs-ene but also on the substrate (called substrate-ene) which allows for photocrosslinking between different layers of PE-enes and also with substrate-ene in the presence of a water-soluble dithiol crosslinking agent via "click" thiol-ene chemistry. The feasibility of this approach has been demonstrated both on a gold model substrate and on an AMX-type anion exchange membrane, both previously functionalized with allyl groups either by sulfur-gold chemistry or by chemical reduction of aryldiazonium salts, respectively.

The versatility and effectiveness of the approach reported here are expected to find widespread interest in different fields of emerging applications, including advanced membrane separation and purification, antifouling and bioactive surface engineering, soft nanotechnology and self-assembly.

Biography:

Valentina Sabatini is a young post-doc researcher in the Department of Chemistry at the University degli Studi di Milano, Italy. Her research interests lie in the area of polymeric materials, ranging from synthesis, characterization, and functionalization of several kinds of polymeric materials to their industrial application. She collaborates actively with researchers in other disciplines of materials science, particularly physical-chemistry and electrochemical area on the development of new hybrid and smart materials. The high number and quality of scientific papers, patents, oral communications in meetings and awards received can demonstrate her passion and devotion to her work and materials science.

Abstract:

Since the mid-1990s, numerous studies on the treatment of natural and industrial waters by photocatalysis have been reported. The photocatalytic process can completely degrade several organic compounds [1] and is promising in the case of polluted surface waters[2], such as lakes or seas, whose contamination may arise from industrial activities, but also from catastrophic events.

In this study, a photocatalytic floating hybrid device was developed for environmental remediation applications in the case of surface waters containing organic contaminants and their vapors, such as fuels, oils, and chemical products. In fact, it may be difficult to remove these compounds using conventional remediation techniques due to the hydric area dimensions to be reclaimed.

The innovative device proposed here is a multilayer polymeric/TiO2 composite with a hydrophobic/superhydrophobic side, necessary to permit the device flotation during its application in water, and a photocatalytic layer active in the degradation of water pollutants. The hydrophobic side was obtained by synthesizing an oxygen permeable Polyacrylate-based polymer with high photochemical, mechanical and thermal resistance. A novel procedure involving the use of fluorinated co-monomers and controlling the polymeric foil morphology during solvent casting deposition was developed[3,4]. On the other side of the polymeric foil, the photoactive TiO₂-based layer was obtained by an ad hoc multi-layer spray-coating deposition of a home-made transparent titania solution. The procedure permitted both to preserve the polymeric support properties and to favor the adhesion of the inorganic coating onto the organic surface, via a protective interlayer made of SiO₂ microparticles, prepared by adopting the Stober method. Starting from a multilayer hybrid composite, a highly versatile photo-catalytically active device was developed: the possibility to easily modulate the dimension of such device can pave the way towards new and strategic applications for both natural and industrial water treatments.

Biography:

Lucio Colombi Ciacchi gained a PhD in materials science in 2002 and holds the Hybrid Materials Interfaces chair at the University of Bremen since 2008. He is the Speaker of the MAPEX Center for Materials and Processes and Coordinator of the interdisciplinary study program “Process-Oriented Materials Research”. He has published more than 90 peer-reviewed papers in materials engineering, chemistry, and physics. His research is devoted to the atomic-scale study of interfaces between different materials and phases, with particular interest in bio-hybrid and soft-matter/hard-matter interfaces, combining both modelling and experimental techniques.

Abstract:

Co-curing of a thermoset (TS) epoxy matrix in contact with thermoplastic (TP) foils is an essential step in a damage-free joining of polymers or polymer-based composites. However, to date, the molecular topology of the resulting hybrid TS/TP interfaces is not known. Also, it remains to be explored whether only physical (non-covalent) interactions between the two components occur, or if instead, and under which conditions, covalent bonds may form as a result of the TS resin chemically reacting with the TP chains. Such details are challenging to resolve via experimental approaches alone, which motivates the use of all-atom molecular simulation techniques in order to shed light on the details of the hybrid interface. Using polyvinylidene difluoride (PVDF) and a multicomponent epoxy resin as model systems, we have developed a computational co-curing protocol that ensures both adequate structural representation and mobility of the PVDF chains and a realistic cross-linking conversion and topology of the epoxy resin. As a result, we reveal that mutually entangled loops of thermoplastic chains and resin strands from across the interface within the extended interphase region separating the two polymers. In tensile stress simulations, we find that these loops contribute to a surprisingly large interfacial strength. In the absence of extrinsic defects, failures nucleate at the PVDF side of the interphase and propagate via a chain-pullout mechanism characteristic of semi-interpenetrating polymer networks involving thermoplastic materials. The possibility of chemical reactions between the epoxy molecules and the polar PVDF chains is explored by means of quantum mechanical calculations at the level of Density Functional Theory. Finally, the kinetics of the diffusion and co-curing conversion processes are estimated via a mesoscopic model based on the numerical solution of reaction-diffusion equations able to reproduce characteristic experimental thicknesses of the TS/TP interface region.

Biography:

Dr. Riley Gatensby graduated from Trinity College Dublin in 2012 with an undergraduate degree in Nanoscience, Physics, and Chemistry of Advanced Materials. He subsequently undertook postgraduate studies where he worked on synthesizing and characterizing two-dimensional semiconducting transition metal dichalcogenides. He earned his PhD in 2018 from the Department of Chemistry, Trinity College Dublin. He is currently a postdoctoral researcher in the Intelligent Nano Surfaces group of Dr. Parvaneh Mokarian. His current research interests focus on the plasma etching of BCP patterns into different substrates for optical, semiconductor, lithographic and energy applications

Abstract:

Nanostructured surfaces that engineer the interaction between incident light and an object are a topic of both scientific and manufacturing significance.¹ One drawback to manufacturing these structured surfaces is their limited up-scalability to large areas due to limitations of conventional UV lithographic approaches, the inability to pattern curved surfaces and the high cost of necessary infrastructure. Block copolymers (BCPs) show much promise for nanolithography applications, as they can address these issues.² In this work, a solution process based on high molecular weight BCP self-assembly is used to impart cylindrical patterns to glass substrates, with subwavelength features.³ The feature sizes and spacings are designed to efficiently scatter visible light.⁴ We present BCP phase separation leading to well-ordered hexagonal nano-patterns with feature diameters of ~130 ± 15 nm and periodicity of ~160 ± 20 nm. Ni ions are selectively incorporated into the P2VP block, and UV/ozone processing allows for the pattern to be transferred as a metal oxide etch mask.⁵ ICP-RIE plasma etching was performed, transferring the pattern into the substrate. The resulting nano-pillars form a Gradual Refractive INdex (GRIN) change and result in drastically reduced reflectance. Over a wide range of angles, the reflectivity is reduced by 40% in the range of 1100 nm – 2 μm, with only one side of the glass, treated. This nano-patterning process based on BCPs is applicable for a wide range of substrates, both curved and planar, it has the added advantage that it avoids the previous inherent size limitations of BCPs (5-100 nm), and it makes surfaces suitable for enhanced transparency, light focusing, anti-reflection and tuning photon absorption. This technique facilitates fabrication of a high density ordered an array of nano-pillars with tunable height, which are easily scalable and can be formed at room temperature. GRIN may now achieve a broadband elimination of reflections, outperforming other anti-reflective coatings for high-quality glass optics.

Biography:

Tianzhu Zhang obtained his PhD degree from the Institute of Chemistry, the Chinese Academy of Sciences in 2003. From 2004 until 2009, he conducted his post-doctoral research at Ghent University (with Prof Dr. Filip Du Prez), the Catholic University of Leuven (with Prof Dr. Erik Nies) in Belgium, at Technische Universitat Munchen and the University of Ulm (with Prof Dr. Bernhard Rieger) in Germany. In 2009, he joined the School of Biological Science and Medical Engineering at Southeast University in China as a full professor. As a head of the research group, his  research interests mainly focus on the surface functionalization of polymer materials and ECM-mimic smart hydrogel. In 2009, he was the Winner of Education Ministry's New Century Excellent Talents Supporting Plan for his excellent work. In 2011 he was awarded the first prize of China Petroleum and Chemical Industry Federation of Science and Technology Progress

Abstract:

In hernia repair, polypropylene (PP) mesh is one of the most common prosthetic materials because it leads to successful long-term treatment. However, when a prosthetic material is placed on an intraperitoneal hernia, it may lead to serious adhesions between the mesh and viscera, which limits its application. In the present study, dopamine methacrylamide (DMA), a derivative of dopamine, was polymerized and then reacted with polyethylene glycol methacrylate (PEGMA) to produce poly(polyethylene glycol methacrylate-co-dopamine methacrylamide) (p(PEGMA-co-DMA)) using traditional free radical polymerization. It was grafted in situ on the PP mesh’s surface utilizing the dopamine catechol group to obtain an anti-adhesive PP mesh. The structure and properties of the p(PEGMA-co-DMA) graft were characterized by Nuclear Magnetic Resonance (NMR), Gel Permeation Chromatography (GPC), Attenuated Total Reflection Flourier Transformed Infrared Spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Thermal Gravimetric Analysis (TGA), water contact angle measurements and scanning electronic microscopy (SEM). NIH-3T3 cells were employed to assess anti-adhesion and biocompatibility in vitro. Moreover, the efficacy of the p(PEGMA-co-DMA)-coating as a barrier for reducing post-surgical adhesions was evaluated with a rat abdominal wall defect model. Compared with the native PP mesh, the p(PEGMA-co-DMA)-grafted PP mesh demonstrated excellent anti-adhesion and biocompatibility properties both in vitro and in vivo testing. The results suggest that this kind of p(PEGMA-co-DMA)-grafted PP mesh is a promising candidate for abdominal wall defect repair.

Biography:

Gyu Leem earned his B.S. in Chemical Engineering from the Hanyang University, Seoul, Korea and Ph.D. in Chemistry from the University of Houston, Houston, TX in 2008. After completing his Ph.D., he spent three years working as a principal scientist at LG R&D in South Korea. He was responsible for the design and synthesis of high-performance water-absorbing polymer materials for personal hygiene products.  In 2012, he moved to the University of Florida and performed postdoctoral research with Professor Kirk S. Schanze as a part of University of North Carolina Energy Frontier Research Center: Center for Solar Fuels, an Energy Frontier Research Center. In 2016, he then moved to the Department of Chemistry at the University of Texas at San Antonio as an assistant professor of research.  Now he is appointed to assistant professor at the State University of New York - College of Environmental Science and Forestry (SUNY ESF), Syracuse, NY in 2018.  His research interests are

1) Polymeric metal chromosphere-catalyst assemblies for solar energy conversion

2) polymer-coated magnetic hydrogels for heavy metal removal from wastewater

3) Photoinduced electron transfer initiation of free radical polymerization for 3-D network polymers    

Abstract:

In natural photosynthesis, a multi-chromophore antenna system absorbs light efficiently and transmits excited-state energy rapidly to a reaction center. Related antenna strategies can be available for dye-sensitized photoelectrochemical cells (DSPECs) applications by using polychromophoric polymers.  DSPECs convert energy from the sun directly into fuel. Toward fabricating DSPEC devices, we reported the synthesis and properties of novel light harvesting polymers featuring pendant polypyridyl ruthenium complexes. These polymers are ionic polyelectrolytes due to the cationic or anionic charge on the individual chromophore centers. As such, the polyelectrolyte can be utilized to fabricate nanostructured polyelectrolyte layer-by-layer (LbL) films. LbL polyelectrolyte self-assembly allows facile control of the polychromophore-catalyst assemblies prepared directly on the surface of semiconductors. The photophysical and electrochemical properties of the polychromophore-catalyst assembly were characterized at the semiconductor interface. The energy and electron transfer processes were investigated in the polymer assembly. Importantly, prolonged photo electrolysis experiments, with the use of a dual working electrode collector−generator cell, reveal production of O2 and H2 from the illuminated photoanode and photocathode. Polymeric chromophore-catalyst assemblies containing chromophore units and an oxidation catalyst were developed to demonstrate its use in light-driven water oxidation and reduction for a DSPEC application. This is the first report to demonstrate the use of polyelectrolyte LbL to construct chromophore−catalyst assemblies for water splitting reaction.

Biography:

Sabad-e-Gul has due to submit her PhD thesis fall this year from Dublin Institute of Technology, Dublin, Ireland. She did M.Phil (Polymer Technology) from University of the Punjab Lahore, Pakistan. She was first elected president of SPIE chapter (DIT). Her reserach work has been published in more than 7 papers in reputed journals and has been a research assistant on enterprise Ireland projects.

Abstract:

The aim of the presented research is to fabricate and test portable holographic sensors for analytes in liquids. The characteristics that are targeted are simplicity of operation, selectivity, sensitivity and relatively low cost. In order to achieve this aim, photonic devices are fabricated by holographic patterning, with a view to their application in environmental and biomedical sensing. Different types of analyte sensitive materials are used to functionalise the surfaces of these photonic devices [1-2].

The sensors reported here are created by holographic recording of surface relief structures in a self-processing photopolymer material. The proposed technique is used as a platform for the fabrication of sensors with readily varied selectivity. In this work we demonstrate that the photonic structures are modified by three different materials in order to achieve sensitivity to three different target analytes.

LTL-zeolite nanoparticles (fig) [3] were used to fabricate a sensor for detection of copper, calcium and lead  ions in fresh water [3]. The current detection limit of the sensors’ response to water is 63 ppm.

The surface structures were also functionalized by coating with dibenzo-18-crown-6 and Tetraethyl p-tert-butylcalix[4]arene for detection of K⁺ and Na⁺, respectively. Both Ionophores have great potential in fabrication of highly sensitive and selective biosensors and the performance of the sensors was investigated. It was observed that functionalisation with dibenzo-18-crown-6 provided a selective response of the devices to K⁺ over Na⁺ and Tetraethyl p-tert-butylcalix[4]arene provided selective response to Na⁺ over K⁺. The sensors respond to K⁺ and Na⁺ within the physiological ranges, which are 3-5 mM and 133 -145 mM, respectively.

Biography:

Abstract:

The synthesis of renewable, sustainable, and environment-friendly polymeric biomaterials has got more attention during the last decade. On the other hand, microwave-assisted organic synthesis has become an extremely attractive synthetic tool at the same time due to its distinctive advantages such as shorter reaction times, higher yields, and limited generation of by-products as well as relatively easy scale-up without detrimental effects. Nevertheless, the use of microwave technology in biomaterials science has been relatively few. Therefore, the synthesis of novel, bio-based polyamides from dimethyl 9-octadecenedioate derived from canola oil and diethylenetriamine as well as p-xylene diamine using 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) as an organic catalyst was studied under microwave irradiation. First, Cross-metathesis of fatty acid methyl esters (FAMEs) from canola oils was carried out using a microwave reactor in solvent-free conditions to get highly pure dimethyl 9-octadecenedioate (diester). Then, Condensation polymerization of diester and diamines as monomers was performed using classical heating and microwave irradiation methods. The resulted polyamides were characterized and analyzed using proton nuclear magnetic resonance spectroscopy (1H-NMR), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), size exclusion chromatography (SEC) and tensile tests. Finally, the beneficial effect of microwave irradiation on the acceleration of the polycondensation of monomers is highlighted. The high molecular bio-based polyamides have the great future potential to be used in different applications as a substitute of petroleum-based polyamides

Biography:

Joseph D. Lichtenhan, Ph.D.  Dr. Lichtenhan is a pioneer and authority in the field of POSS® additives. POSS has been hailed as the first entirely new chemical class of monomers to be developed since 1955. His insights into their commercial utility launched the global sales for POSS® in 1998. Dr. Lichtenhan has excelled at technology transition and the establishment of a global footprint for POSS® via innovative sales and marketing techniques.

Abstract:

Statement of the Problem: High-performance aromatic polymers such as PEEK, PEKK, PPS, PPE, PEI etc., are well known to provide outstanding thermal and mechanical properties.  They also require processing at high temperatures.  In the case of PEEK and PEKK, processing temperatures can be in excess of 350 °C.  Even more challenging is when these polymers are combined with filler or fiber reinforcements.  Infilled systems, polymer viscosity increases further which results in increased extruder torque, temperatures, pressures that approach the processing limits of compounding equipment.

A common solution to reducing viscosity is to decrease the molecular weight of the polymer or to use bimodal molecular weight distributions which, while allowable for some uses, can decreased mechanical performance.

The high processing temperatures of aromatic thermoplastics also limit the use of traditional plasticizers due to their propensity to degrade and volatilize during compounding.

For difficult to process polymers, POSS additives are uniquely well suited.  In particular, POSS cages bearing all phenyl groups (such as dodecaphony) melt and are thermally stable in the 400°C temperature range.  When phenyl POSS cages also contain silanols (such as the heptaphenyl trisilanol), they reduce viscosity and behave as high-temperature dispersants.

POSS® chemical additives are a family of chemicals that melds the desirable thermal stability and modulus of inorganic additives (SiO1.5) with organic (R) compatibility to render utility with heritage polymers, resins, monomers, and ingredients.

The mechanism enabling POSS to provide flow enhancement in polymers have been postulated using Einstein sub-rheology. Additionally, the flow enhancement has been described to result from weak forces (Van der Waals, or London forces) between the POSS cages and polymer chain which causes deviation from classical hard-sphere theory.  Perhaps a simpler explanation is that POSS cages melt during compounding.  In the molten state, the cages act as a low viscosity liquid and thus provides a reduction in extrusion torque and viscosity of the polymers.  Upon cooling both the POSS cages and the polymer re-solidify.  The solidification of POSS is highly advantageous as it does not result in post-processing plasticization. At only 1.5 nm in diameter, POSS cages provide a large amount of surface area and volume when incorporated into formulations.  Thus, in addition to flow enhancement, POSS cages can provide surface area and volume control around fillers and other additives.  The dispersion of fillers is particularly well suited to POSS cages bearing silanol groups (such as trisilanol heptaphenyl POSS).  Additionally, the high surface area of POSS can also aid in the nucleation and growth of polymer spherulites.  In this light, POSS cages can be utilized to speed-up processing conditions and improve cycle times.

Biography:

Abuzar Kabir is a Research Assistant Professor at the Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA. His research focusses on the synthesis, characterization, and applications of novel sol-gel derived advanced material systems in the form of chromatographic stationary phases, surface coatings of high-efficiency microextraction sorbents, nanoparticles, microporous and mesoporous functionalized sorbents, molecularly imprinted polymers for analyzing trace and ultra-trace level concentration of polar, medium polar, nonpolar, ionic analytes, heavy metals, and organometallic pollutants from complex sample matrices. His inventions, fabric phase sorptive extraction (FPSE), and dynamic fabric phase sorptive extraction (DFPSE), capsule phase microextraction (CPME), molecular imprinting technology, super polar sorbents, In-Vial microextraction (IVME) have drawn global attention. He has developed and formulated numerous high-efficiency sol-gel hybrid inorganic-organic sorbents based on Silicon, Titanium, Zirconium, Tantalum, Germanium chemistries. Dr. Kabir has authored 16 patents, 9 book chapters, 52 journal articles and 90 conference papers.

Abstract:

Due to the explosive growth of anthropogenic activities during the last couple of decades, freshwater systems across the world have been continuously polluted by numerous toxic and hazardous synthetic organic compounds produced for industrial, domestic and agricultural usage. Many of these pollutants are known as persistent organic pollutants (POSs). When POPs are released into the environment, they remain unchanged for a long period of time by resisting photocatalytic, chemical and biological degradation. Due to their prolonged presence in the environment, many of these pollutants eventually find their way in the food chain, with severe ramifications in the health and well-being of humanity.  As such, it is imperative that these compounds be efficiently removed from environmental water through more efficient sewerage treatment processes and other reliable remediation techniques.

Among many classical processes used in removing pollutants from water such as precipitation, coagulation, sedimentation, filtration, adsorption, chemical oxidation, and ion exchange, adsorption is one of the most effective removal technique. A large number of carbonaceous adsorbents including activated carbon, carbon nanotube, biochars, graphene, beta-cyclodextrin, calixarenes, Carboxen, fullerene, cation exchange resins, anion exchange resins, zwitterionic resins are used as adsorbents in sewerage treatment plants. These adsorbents offer a large variety of intermolecular interactions towards the analytes via µ-µ stacking interactions, cation-µ bonding interactions, electron donor-acceptor interactions, hydrophobic interactions, hydrogen bonding interaction, cation exchange, anion exchange, dipole-dipole interactions etc. Many of these adsorbents possess extremely high surface area and demonstrate a strong tendency to form agglomeration. As such, when they are used in their pristine form, a large portion of their available surface area cannot be readily accessed by the analytes due to their agglomeration and formation of lump. As a result, the adsorption capacities of these adsorbents remain largely unexploited during their applications. The agglomeration of these unique particulate matters can be inhibited by encapsulated them into sol-gel silica network. Sol-gel chemistry provides a convenient and mild reaction pathway to create pure silica or organically modified silica 3-D network. Addition of sol-gel active organic polymer(s) as an additive in the soil solution during the sol-gel synthesis is also a common practice to engineer the selectivity of the resulting sol-gel sorbents. Addition of adsorbent particles into the soil solution during sol-gel synthesis results in a sol-gel composite sorbent system with homogeneously trapped particulate matters. Due to the inherently porous and open architecture of sol-gel silica network, the encapsulated particulate matters maintain their high surface area as well as freely accessible interaction sites. As such, the synergistic combination of silica chemistry, organic polymer chemistry as well as the chemistry of particulate matters result in robust composite material systems capable of exerting intermolecular/ionic interactions towards a wide variety of analytes including polar, medium polar, nonpolar, ionic, and metal species and successfully trap them in the sol-gel composite sorbent matrices. Analytical data obtained from a number of real-life applications of the sol-gel composite sorbents including endocrine disrupting chemicals (EDCs), Pharmaceuticals and personal care products (PPCPs), polycyclic aromatic hydrocarbon (PAHs) in environmental water will be presented.

Biography:

Milana Trifkovic obtained her Ph.D. from the Western University in London, Canada, specializing in real time optimal control of crystallization of pharmaceuticals and polymer extrusion. Following her PhD studies, she joined Chemical Engineering and Materials Science Department at the University of Minnesota as a Natural Sciences and Engineering Research Council (NSERC) of Canada Postdoctoral Fellow (PDF). She is an Associate Professor in the Department of Chemical and Petroleum Engineering at the University of Calgary. Her current focus is in advanced materials design, operation and control of complex, non-linear engineering systems.  Her group seeks solutions to these problems through a combination of theoretical and experimental research that enable transforming promising lab concepts into concrete solutions to pressing problems in energy sector.

Abstract:

A few decades of intense research efforts have enabled implementation of polymer nanocomposites and polymer blend nanocomposites within numerous commercial applications. With the estimated annual growth rate of 25%, their application spectrum keeps on growing. However, controlling the dispersion state of nanoparticles in the polymer or polymer blend matrices is difficult to achieve due to the complex and little-understood interplay of particle compatibility, transport behavior, and theology. Controlling the dispersion state then is central to designing a platform for engineering nanocomposite structures for an application of interest.

Recent results will be presented which establish that the effect of polymer-filler interactions at the molecular level dictates the extent of filler dispersion and consequent bulk properties of the derived polymer nanocomposites (PNCs). However, contrary to the common belief, we show that agglomeration of conductive nanofillers, resulting from the low interfacial interaction between polymer and nanofiller, can be highly beneficial for enhancing the electrical properties of the derived nanocomposites. These nanocomposites have been studied using a multi-scale approach, from evaluation of their bulk properties via rheology and conductivity measurements, to microscale characterization via imaging by laser scanning confocal and transmission electron microscopy, and measurement of particle/polymer interactions via atomic force microscopy. This multi-time-scale analysis lends itself naturally to a hierarchical control framework of the particle dispersion in PNCs, whereby overall objectives for the derived nanocomposites can be addressed at a bulk level, while the micro and molecular scale measurements can be used to guide the selection of polymer/nanofiller candidates for an application of interest.

Biography:

Yasser Hassan has his expertise in the synthesis of semiconductor nanocrystals (NCs) and their application in the state-of-the-art engineering of efficient and low-cost thin-film optoelectronic devices, solar cells and light diodes (LEDs). He is currently a Postdoctoral Research Associate at the Oxford Photovoltaics and optoelectronics Devices Group under Prof. Henry Snaith, University of Oxford. Prior to his current position, he completed his PhD of Chemical Engineering and Applied Chemistry in 2016 from the University of Toronto. Currently, his core contribution focuses on the creation of highly efficient white LEDs with high brightness combined with operational durability. He examines a wide range of different highly emissive and stable perovskite NCs (2D and 3D) emitters, with controlled size and surface structure, which have the desirable emission band gap to cover the whole panchromatic absorption profile with the focus on their optoelectronic applications

Abstract:

Metal halide perovskites are promising candidates for use in light emitting diodes (LEDs), due to their potential for colour tuneable and high luminescence efficiency. While recent advances in perovskite-based light emitting diodes (PeLEDs) have resulted in external quantum efficiencies (EQEs) exceeding 12.4 % for the green emitters, and infrared emitters based on 3D/2D mixed dimensional perovskites have exceeded 15%, the EQEs of the red and blue emitters still lag behind. A critical issue to date is creating highly emissive and stable perovskite emitter with the desirable emission band gap (especially red and blue region) to achieve full-colour displays and white LEDs. A critical issue to date is creating highly emissive and stable perovskite emitter with the desirable emission band gap (especially red and blue region) to achieve full-colour displays and white LEDs. Herein, we report the preparation and characterization of a highly luminescent air-stable suspension of both red cubic CH3NH3PbI3 perovskite nanocrystals (NCs) and high-quality, stable blue colloidal perovskite CsPbBr3 nanoplatelets. Both the red NCs and the blue nanoplatelets exhibit controlled optoelectronic properties with colour purity in the recommended emitting regions (according to Rec. 2020) of band gaps of 1.96 and 2.65 eV, respectively. Photoluminescence quantum yields (PLQY) exceeding 95% for the red NCs and 92% for the blue was achieved. We demonstrate the utility of these nanocrystals in PeLEDs

Biography:

Alan Jankowski completed his PhD in Mechanics and Materials Science at Rutgers University in 1987 and has held scientific, faculty, and management positions at Lawrence Livermore National Laboratory, the Texas Technological University, and Sandia National Laboratory. He has published 135 journal papers, received 29 US Patents, and given 40 invited presentations at international conferences

Abstract:

The decomposition of a one-dimensional composition wave in Cu-Ni(Fe) nanolaminate structures is quantified using x-ray diffraction to quantify the kinetics of interdiffusion processes. A schematic of an A/B nanolaminate structure with A (dark-shaded) and B (light-shaded) atoms is shown (below left) as viewed in cross-section. Features are shown such as a threading dislocation (d), grain boundary (gb) between columnar grains, and the A/B layer pair thickness, i.e. the composition wavelength (l_A/B). Cu-Ni(Fe) is a spinodal alloy system where the growth or decay growth of the composition modulation occurs within or above the critical temperature for the chemical spinodal, respectively. A transmission electron microscope, bright-field image and selected area diffraction pattern (insert) are shown (below right) for a Cu-Ni(Fe) nanolaminate with a 4.34 nm composition wavelength, revealing its ultra-fine grain nanocrystalline structure. Evidence of a negative interdiffusivity is found for each of sixteen different nanolaminate samples that are aged at room temperature over a composition wavelength range of 2.1–10.6 nm. A diffusivity value ÄŽ of 1.77 × 10⁻²⁴ cm²·s⁻¹ is determined for the alloy system at room temperature – perhaps, the first such measurement at a ratio of melt temperature to test temperature that is greater than 5. Although this diffusivity value is extremely small, it is several orders of magnitude greater than that value extrapolated from high temperature to room temperature for a bulk diffusion mechanism. Diffusion mechanisms that are operative from room to high temperatures for the Cu-Ni(Fe) nanolaminate structures (shown in the image below) are reviewed, including the possible effects of short-circuit diffusion through interlayer grain boundaries.

Biography:

Mehry Fattah is a researcher and engineer who has the experience of working within academia and industry on surface engineering, corrosion, and coatings for 9 years. She received her Ph.D. and MSc from Amirkabir University in Metallurgical Engineering (University of Toronto Canadian Accreditation Equivalency). She has successfully proposed a corrosion model that shows how microstructure and composition affect the corrosion mechanism, which leads to lower cost and more efficient solutions to protect the surface deterioration through general and pitting corrosion. She conducted cathodic protection designs which resulted in increasing lifespan and saving money in Oil and Gas industry. She has conference and ISI papers published as the result of her works. She enjoys facing new challenges and forging ahead to find the solutions under tight time frames while inspiring team members.

Abstract:

In this paper, the influence of plasma nitriding and treatment temperature on the corrosion and hardness properties, microstructure and composition of AISI 4140 low alloy steel was investigated. Plasma nitriding treatments carried out in a gas mixture of 85% N2-15% H2, for 5 h at a chamber pressure of 4 mbar at different treatment temperatures varying from 520 to 620 °C. Optical microscopy, scanning electron microscopy, X-ray diffraction, hardness and microhardness measurements and potentiodynamic polarization technique in 3.5% NaCl solution, was used to study the plasma nitrided low alloy steel. The results revealed that plasma nitriding at temperatures between 520 and 570°C can produce a ε phase dominant compound layer which is supported by a diffusion zone. With increasing the treatment temperature from 570 to 620°C, γ′ phase appeared. The thickness of the compound layer and diffusion zone increased with increasing the treatment temperature. The thickest compound layer was produced in the sample was treated at 620°C, composed of two outer and inner layers with different microstructures and compositions and the maximum amount of nitride phases was detected at the depth of 20- 35µm from the surface. The hardness of the surface remarkably improved after plasma nitriding and reached up to a maximum of 945 HV0.05 at 520°C which is almost 5 times higher than of the untreated sample.

Corrosion resistance increased after plasma nitriding at 520°C and continued to increase with increasing the treatment temperature to 545°C. With further increase of temperature from 545°C to 620°C, corrosion resistance decreased to the amount of the untreated sample. The sample treated at 545°C showed the most improved corrosion resistance while simultaneously attained surface hardness as high as about 4 times of the untreated sample.

Biography:

Sherif  Mostafa is a postdoctoral fellow at the University of Calgary. He works as a Manager of an analytical chemistry laboratory. He has MSc degree in 2005 in chemical engineering with Thesis Title " Fiber Treatment for Reduction of Radar Signature ".Also, he has Ph.D. degree in 2014 in chemical engineering with thesis title " Creation of Advanced Ceramic Materials in Nanotechnology Range". He has experience in nanoceramic materials synthesis, water treatment, decontamination, antibacterial materials, RAM and preparation of gas sensing materials. Sherif participates in many types of research in different fields. He supervised many types of research in various  fields

Abstract:

SnO2 and TiO2 were loaded onto multi-walled carbon nanotubes (MWCNTs) to form a new composite for the sensing of volatile organic compounds (VOCs). To do this, MWCNTs were dispersed into mixtures of 0.5 wt.% SnO2/TiO2. The TiO2 was converted from anatase to rutile phase through the use of rapid microwave and intense pulsed light techniques. These processes are also used for drying to obtain the materials as a dry powder. The materials were then incorporated into a solution of 5 wt.% polyvinyl butyral (PVB) to form a sol-gel. A gas sensing device was formed by spin coating the materials onto quartz crystal microbalance (QCM). FE-SEM and XRD characterizations indicated that the inclusion of CNTs did not affect the particle size or the morphology of the thin film. Most importantly, the sensor based on the SnO2-TiO2-MWCNT hybrid showed the high and fast response, high selectivity to VOCs relative to hydrogen gas and good stability. Mass and molar adsorption was calculated based on changes in the frequency by the Sauerbrey model. The sensing properties were investigated with different VOCs including ethanol, methanol, isopropanol, and toluene at different concentrations and operating temperatures. Room temperature sensing was achieved and the highest sensitivity was shown towards ethanol with a response time as low as 5 seconds.

Biography:

Mrinmoy Misra is an Assistant Professor at the Department of Bionano Technology, Gachon University, South Korea. He graduated with a Ph.D. from Academy of Scientific & Innovative Research, India. He has received awards such as Indian Institute of Technology Kanpur postdoctoral fellowship, 2015, Award of science & engineering research board (SERB) National Post-Doctoral fellowship, 2016. His research interests include thin-film fabrication, nanomaterial-based sensor, photocatalytic materials, nanoparticle synthesis and characterization and solar cells. Dr. Misra has authored 13 research articles in SCI journals

Abstract:

In this paper, we generate piezoelectricity in one-directionally aligned bi-axially grown ZnO nanorods.  The applied force is horizontal to the polarization direction. The piezo-phototronic induced voltage generated from a bending radius is experimentally measured for ZnO NRs. The combination of the photocatalytic effect and piezoelectrochemical phenomenon of ZnO NRs has been used for the degradation of an organic pollutant in the aqueous medium. The mechanical stress creates a polar charge field on the surface of ZnO NRs, which acts as a driving force to enhance the charge separation of photogenerated electron and hole pairs. Subsequently, the charge separation increases the photocatalytic activity of ZnO NRs. Further, coumarin (COU), used as a fluorescent probe for the purpose of detection and measurement of OH. radical is generated during photocatalysis process. The synergistic effect of strain-induced chemical reactions and UV photocatalytic activity can deliver a lucrative approach for degradation of organic pollutants. In addition, this work exhibits an exciting new model of a piezo-phototronic device.

Biography:

Ramya Nair completed her M.Sc. from University of Mumbai with an outstanding grade in the year 2012. During the master's program, she successfully completed six-month dissertation work at Tata Institute of Fundamental Research(TIFR), Mumbai.  Afterward, she got selected in prestigious DAE fellowship scheme for Ph.D. in basic sciences and currently she is pursuing her research work as the senior research fellow at Chemistry Division of Bhabha Atomic Research Center, Mumbai. She has five papers published in journals of international repute and participated in several international conferences and workshops.

Abstract:

GdBO3 belongs to the category of rare earth borates. Its outstanding optical properties with high thermal and chemical stability enable them as potential candidates for solid-state lighting, plasma display panels etc. The motivation of this work is to understand the influence of local environments on luminescence properties of Eu3+ in three different phases of GdBO3, namely monoclinic, triclinic and nano-crystalline forms as this will be helpful for selecting a suitable host for getting optimum luminescence and to get a basic understanding on phase and local environment dependent optical parameters. GdBO3 containing 1at.% Eu3+ were prepared in nano-crystalline, monoclinic and triclinic forms in the present study based on hydrothermal, polyol and solid state reaction of  B, Gd and Eu precursors and subjected structural and luminescence studies. TEM images and SAED patterns confirmed the formation of nanorods of GdBO3 having the monoclinic structure (length~ 200 nm, width ~10 nm) while FTIR patterns have confirmed that in nanorods and triclinic phase boron exists in both diagonal and tetrahedral configurations. Unlike this in monoclinic GdBO3 boron exists only as BO4 structural units constituting B3O99- groups. The relative intensity ratios of electric dipole allowed to magnetic dipole transitions of Eu3+ in triclinic and nanorods of GdBO3 are 2 and 2.3 respectively and are found to be higher than that of monoclinic phase (1.4). The CIE colour coordinates are found to be (0.60, 0.34) for monoclinic, (0.64, 0.36) for triclinic phases and (0.62,0.35) for nanorods, suggesting that the nanorods have improved red colour characteristics compared to the other two forms

Biography:

Haijin Liu got her Ph.D. degree in 2010 in environmental science. She works at Henan Normal University as an associate professor. She has been focused on the synthesis of new functional materials and their applications in the environmental area. She has fabricated various functional materials and applied them to adsorption, degradation, energy storage, disinfection, and so on. She worked deeply into the degradation processes and explored different mechanisms. As a visiting scholar, she collaborated with Dr. Aicheng Chen at Lakehead University in Canada during 2013-2014 and worked with Huijun Zhao at Griffith University in Australia in 2016. She hosted and participated in many Chinese projects and owned several Chinese patents.

Abstract:

Statement of the Problem: Photocatalytic technologies, as promising strategies for environmental control, have broad and attractive prospects for the degradation of water and air resident pollutants. However, most single photocatalysts possess some defects, such as narrow light absorption range, the high recombination rate of photo-induced electrons and holes and so on.

Methodology & Theoretical Orientation: In this study, binary heterojunction photocatalysts, SnS2/Bi2MoO6 and SnO2/BiOBr were synthesized by mild hydrothermal methods for the first time. The photocatalytic activities of these materials were evaluated through the degradation of a series of organic pollutants, which possess stable chemical structures, intense carcinogenicity, as well as being recalcitrant to degradation.

Findings: The experimental results indicated that the SnS2/Bi2MoO6 and SnO2/BiOBr composites exhibited significantly enhanced performance in contrast to pure Bi2MoO6, SnS2, SnO2 or BiOBr. In details, the degradation rate constant of CV (crystal violet) using 5 wt% SnS2/Bi2MoO6 photocatalyst was 3.6 times that of the Bi2MoO6 and 2.4 times that of SnS2;  the degradation rate of RhB attained ~98.2% in 20 min. using 30 wt% SnO2/BiOBr, which was close to twice that of pure BiOBr, and 10 times that of pure SnO2. Furthermore, the primary active species in the photocatalytic oxidation process were detected via radical trapping experiments and ESR spectra.

Conclusion & Significance: Two photocatalytic mechanisms were proposed according to the different systems above to elucidate the improvement in photocatalytic efficiency. We trust that the work may provide further knowledge of the design and synthesis of advanced photocatalysts, as well as to inspire further applications of photocatalysts for water purification under visible light irradiation