Biography:

Thi-Thanh-Tam Nguyen has received her Ph.D. 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:

Thi-Thanh-Tam Nguyen has received her Ph.D. 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 and is promising in the case of polluted surface waters, 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. 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:

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 and is promising in the case of polluted surface waters, 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. 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 Ph.D. 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 Ph.D. 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 Ph.D. 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 Ph.D. 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 research 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 the 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 functionalize the surfaces of these photonic devices [1-2].

The sensors reported here are created by a 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 Ph.D. 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 Ph.D. 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. Several illustrative case studies systems will be dis