2^nd International Conference and Exhibition on Polymer Chemistry November 15-17, 2017 San Antonio, USA

Biography:

Gyu Leem earned his B.S. in chemical engineering from the Hanyang University and Ph.D. in Chemistry from the University of Houston 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 baby diapers. 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. He is currently appointed assistant professor of research at the chemistry department at the University of Texas at San Antonio in 2017. His research is focusing on water oxidation, carbon dioxide reduction, and DSPEC water splitting and proton reduction

Abstract:

Statement of the Problem: The polymer industry and its products are Dye-sensitized photoelectrochemical cells (DSPECs) convert energy from the sun directly into fuel. The DSPEC approach is a hybrid based on molecular light absorption and excited state electron or hole injection into the conduction or valence bands of high band gap semiconductors. Toward fabricating DSPEC devices, we have reported polymer-based ruthenium(II) polypyridyl chromophore-catalyst assemblies on TiO2 by using a Layer-by-Layer (LbL) self-assembly process for light driven water oxidation. The photophysical and electrochemical properties of the polychromophore-catalyst assembly were characterized in a solution and at the semiconductor interface and the energy/electron transfer processes were investigated in the polymer assembly. Importantly, photocurrent measurements of the polyelectrolyte LbL films formed on mesoporous semiconductor substrates demonstrate a clear anodic photocurrent response, coupled with the observation of O2. Also, we developed LbL polyelectrolyte assemblies consisting of an anionic π-conjugated poly(isoindigo-co-thiophene) (Pilt) and polyacrylic acid stabilized Pt nanoparticles (PAA-Pt) as proton reduction catalyst, co-deposited with poly(diallyldimethylammonium chloride) (PDDA) as an inert polycation. LbL self-assembly occurs by the alternate exposure of a metal oxide substrate to solutions of oppositely charged polyelectrolytes. UV-visible absorption spectroscopy reveal that multilayer deposition progressively increases the film thickness on ITO substrates. A photocurrent measurement of ITO//(PDDA/Pilt)10(PDDA/PAA-Pt)10 under AM 1.5 illumination and applied bias - 0.4 V shows a photocurrent response. This result provides new guidance for the LbL self-assembly of polychromophores/catalysts for light driven solar-fuels photoelectrochemical systems.

Biography:

Sungjin Park has completed his PhD from KAIST, South Korea and Postdoctoral studies from Northwestern University and University of Texas at Austin, USA. Presently, he is an Associate Professor at Inha University, South Korea. His group is working on nanochemistry and various catalytic applications. He has published more than 80 papers in reputed journals

Abstract:

Chemical designing on nanomaterials in molecular level would be a promising route to create new hybrid materials and to control various properties of nano- and molecular materials. Organometallic compounds have been a center of molecular catalysts with preeminent catalytic activity and selectivity in a wide range of chemical transformations. As carbon-based nanomaterials, such as graphene-based materials, carbon nanotubes and carbon nitrides are sterically bulky and they exhibit a wide spectrum of electrical properties, they can dramatically tune the catalytic behavior of transition metal-based active species. Hybridization of organometallic complexes with graphene-based materials can give rise to enhance catalytic performances. In this presentation, I will discuss my recent research activities on the fundamental chemistry of carbon-based nanomaterials as well as catalytic applications.

Biography:

Abstract:

Summary

This study reports a series of polymers with an insulating backbone and varying ratios of 2-(10H-phenothiazin-10-yl)dibenzothiophene-S,S-dioxide as a pendant TADF unit. Green emitting OLED devices employing these polymers as spin-coated emitting layers give high performance.

Introduction
 

Organic light-emitting diode (OLED) devices have been in continous development since the early 1960s. To improve the external quantum efficiency (EQE) of OLEDs,  extensive studies have focused on synthesizing new emissive materials. One of the most important challenges in this field stems from the fact that fluorescent materials harvest emission only from singlet excitons and thus have the limitation of reaching a maximum internal quantum efficiency (IQE) of 25%, whereas statistically 75% triplet excitons are wasted. Metal-free, thermally activated delayed fluorescence (TADF) materials are considered to be third-generation emitters for OLEDs.^1-3 Polymeric TADF emitters are particularly suitable for solution processing technologies. However, synthesizing TADF oligomers and polymers is challenging and there are no clear guidelines for their optimal molecular structures. Firstly, simultaneously achieving a small energy splitting between the singlet and triplet states (ΔE_ST) and suppressing internal conversion is very difficult in molecules containing numerous atoms. Secondly, the triplet population in polymers is easily quenched by intramolecular and intermolecular triplet-triplet annihilation.⁴ However, there are only a few reported examples of polymeric TADF materials.

Discussion

A series of polymers with an insulating backbone and varying ratios of 2-(10H-phenothiazin-10-yl)dibenzothiophene-S,S-dioxide as a pendant TADF unit, copo1, copo2, copo3 and homopo, have been synthesized and characterized successfully. They exhibit good film forming ability, high thermal decomposition temperatures and suitable glass transition temperatures. Steady-state and time-resolved fluorescence spectroscopic data confirm the efficient TADF properties of the polymers. Styrene, as a co-monomer, is shown to be a good dispersing unit for the TADF groups, by greatly supressing the internal conversion and triplet-triplet annihilation. Increasing the styrene content within the copolymers results in relatively high triplet energy, small energy splitting between the singlet and triplet states (DE_ST) and a strong contribution from delayed fluorescence to the overall emission. Green emitting OLED devices employing these polymers as spin-coated emitting layers give high performance, which is dramatically enhanced in the copolymers compared to the homopolymer. Within the series, copo1 with a regiorandom ratio of 37% TADF units : 63% styrene units displays the best performance with a maximum external quantum efficiency (EQE) of 20.1% and EQE at 100 cd m^-2 of 5.3%.

Conclusions

In summary, a series of pendant polymers with 2-(10H-phenothiazin-10-yl) dibenzothiophene-S,S-dioxide as TADF units and insulating styrene units as side chains have been synthesized and structure/property/OLED performance relationships have been established. Photophysical data confirm that for all the polymers the reverse intersystem crossing mechanism is able to compete with internal conversion and triplet-triplet annihilation. The effect of styrene content on the properties of the TADF properties of the polymers has been evaluated. The triplet energy and the delayed fluorescence contribution increases with increasing styrene content of the copolymers; meanwhile, the energy splitting between the singlet and triplet states (DE_ST) decreases with reducing styrene content of copolymers. OLED devices based these polymers as spin-coated emitting layers gave high performance, which is enhanced for the copolymers compared to the homopolymer. The best EL performance was achieved for the copo1-based device with CE_max of 61.3 cd/A, PE_max of 40.1 lm/W, and EQE_max of 20.1%. To our knowledge this is the highest EQE reported to date for a TADF polymer.^26-30 Furthermore, at 100 cd m^-2 the EQE was 5.3%. High EQE, even at very low luminance, is widely recognized as an important figure-of-merit for OLED efficiencies.³⁸ The key molecular features we have developed in this work, namely a non-conductive polymer backbone with pendant TADF units separated by non-emissive units, should be versatile for the design of new families of TADF polymers. It remains to be seen if polymers, which have the potential benefits of high thermal stability, good film-forming ability and reduced phase separation, can be widely exploited for color tuning and enhanced TADF-OLED performance.

Biography:

Ming-Qiang Zhu has his expertise in Optoelectronic Polymer Chemistry, Super-Resolution Fluorescent Imaging, Fluorescent Sensors as well as their application in Biomedical Engineering. He is a Professor of Chemistry and Optoelectronics in Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China

Abstract:

The cross-coupling reactions have been used in general C-C bond formation to develop new π-conjugated molecular topological configurations, which is an essential objective for material chemists and can be used extensively in optoelectronic devices such as chemical biosensing, organic light emitting diode (OLED) and organic photovoltaics. Here, we report the general twofold germinal cross-coupling (GCC) for C-C bond formation at 1,1-dibromoolefin over heterogeneous Pd catalysts for multiple π-conjugated molecular topological configurations. We employ a series of recipes from a library of precursors to produce π-conjugated macrocyclics, conjugated dendrimers, linear conjugated polymers, mesoporous conjugated polymer nanoparticles and 2-3 dimensional conjugated covalent organic frameworks (COF). This universal strategy toward specific π-conjugated molecular topological configurations enables efficient coupling of aryl bromides with various coupling partners with high activity and selectivity under mild conditions. The π-conjugated macrocyclics, dendrimers and 1-D polymers show featured molecular assembly and fluorescence properties. 2D and 3D covalent organic frameworks show excellent N2-adsorption and catalytic activity and recyclability in heterogeneous Suzuki-Miyaura cross-coupling reaction.

Biography:

Joseph D Lichtenhan is a Co-Founder of Hybrid Plastics Inc. and served at its CEO and President for 18 years.  He is a pioneer and world 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. He 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: The major cause of battlefield mortality and morbidity is uncontrolled hemorrhage, with non-compressible wounds particularly to blame.  Many attempts have been made to find a product or device that fulfills the Armed Forces designation of a "perfect" hemostat, but little success has been achieved.

POSS (polyhedral oligomeric silsesquioxane) additives provide unique opportunities to rationally control permeation, transport and surface modification of both man-made and biologically relevant materials.  POSS enhanced medical and personal care products have been in the UK and US markets for several years. This presentation will highlight POSS® as a hemostatic device.

Recently we conducted preliminary tests on the in vivo hemostatic capabilities of a syringible semi-liquid elastomer. We demonstrated hemostatic properties in vitro, and found the POSS formulation exhibits many of the desired properties of an ideal hemostat.  Additionally, we observed that POSS reduced or stopped hemorrhage in what currently is known as the standard Armed Forces porcine model of uncontrolled hemorrhage.

The mechanism of action of the POSS viscoelastic hemostat, along with its comparative performance relative to other hemostatic agents will be presented

Biography:

Hongcai Gao has completed his PhD from Nanyang Technological University and started his Postdoctoral studies in 2013 at the University of Texas at Austin with Prof. John B. Goodenough. His research is focused on the synthesis of polymer electrolytes for solid-state rechargeable batteries. He has published more than 20 papers in reputed journals

Abstract:

Abstract

The extensive availability of sodium motivates the development of low cost sodium batteries for large scale applications such as powering an electric road vehicle or stationary storage of electric power generated by variable wind or solar energy. However, the use of flammable liquid electrolytes has safety issues, especially in large-scale batteries. The ability to plate/strip a sodium anode reversibly makes possible a safe, low cost rechargeable battery provided a suitable sodium ion electrolyte interphase between the solid electrolyte and a solid insertion compound cathode host can be developed. Gel polymer and plastic crystal sodium ion electrolytes are shown to provide the needed electrolyte/cathode interface to provide all solid state cells of long cycle life and adequate rates at 60 °C

Biography:

Shouke Yan is Professor in the College of Material Sciences and Engineering at Beijing University of Chemical Technology (BUCT) in Beijing. He has completed his MS in Polymer Science at the Changchun Institute of Applied Chemistry, the Chinese Academy of Sciences (CIAC-CAS). He has earned his PhD in Polymer Science at the CIAC-CAS under the joint guidance of Prof. Decai Yang and Prof. J Petermann (Dortmund University, Germany) through a sandwich program between the CAS and the Max-Planck-Society. He then took a position on the research staff at Dortmund University. In 2002, he has returned to China through the Hundred Talents Program to become full Professor at the Institute of Chemistry, the Chinese Academy of Sciences (ICCAS). He has been recognized with several honors, including the Excellent Hundred Talents Award and an NSFC Outstanding Youth Fund. His current research involves surface-induced polymer crystallization, orientation-induced polymer crystallization, and phase transition of crystalline polymers

Abstract:

The multiscale morphologies of the polymeric materials in the condensed state exhibit pronounced influences on the mechanical and physical properties of the polymers. For crystalline polymers, the crystalline structure and crystal orientation provide another most important key factor in regulating the property and/or even functionality of a polymer. Therefore, the study on the crystallization of semicrystalline polymers under various conditions is an everlasting research topic.

The crystallization of polymers is generally divided into two stages, i.e. nucleation and crystal growth. The nucleation can take place homogeneously or heterogeneously when it is induced by the presence of heterogeneities. Crystallization of polymers on foreign surfaces provides a typical example of heterogeneous nucleation. The study on crystal growth of polymers on oriented substrate with unique crystallographic interaction is of particular interest from both practical and scientific points of view. It is now well documented that the existence of a foreign surface can alter the crystallization kinetics, as well as the resultant crystal structure and morphology of a polymer. Figure 1 presents an example of the oriented iPP induced unique cross-hatched PE structure, in which the molecular chains of both polymers 50° apart from each other. This provides an efficient way for fabricating special structure with desired property or/and functionality of the polymeric materials.

We here provide context as to how the crystal growth of polymers on oriented substrate and the influence of the substrate on the crystallization process and the resultant unique crystal structure and morphology of polymers. The advantages of surface-induced polymer crystallization to fabricate polymeric materials with improved property or enhanced efficiency will be described with some examples.

Biography:

Jin-lian Hu has obtained her PhD from University of Manchester Institute of Science and Technology, and now is the Professor of Hong Kong Polytechnic University. Before appointed as a Professor at the University, she has Founded the Shape Memory Textile Centre in 2003. Her research fields include shape memory materials and textiles. She and her research group have invented the world’s first cellulose-based shape memory fabric, and registered about 50 patents in the US, China and other countries. She has published several books/book chapters, and more than 250 research articles. There are more than 25 PhD students and about 35 Postdoctoral fellows studied/studying under her supervision in the Shape Memory Polymer and smart textiles areas alone

Abstract:

Many natural materials demonstrate adaptive abilities to keenly respond upon triggering of a suitable external stimulus. Nowadays, self-adaptive breathable polymeric membrane (SBPM) is becoming a fundamental material in various advanced applications such as protective garments/shoes, chemical/medical equipment, sophisticated electronics, and construction materials. SMPM usually introduces in the garment for the enhancing the comfort to the wearer body in extreme environmental conditions. In this context, a series of segmented shape memory polyurethanes (SMPU) was synthesis by adjusting the molecular weight of macroglycol, hard to soft ratio, and incorporation of carbon dot (highly oxygenating groups containing nanoparticles) in different weight % to obtain the suitable SBPM. SMPU showed good self-adaptive WVP by changing the free volume in their soft-segments upon triggering of a stimulus, especially heat. It is found that the mobility of soft segment is low below its transition temperature (Ttrans) and SMPU acts as an insulator. It helps to maintain the warmth and moisten skin along with a low WVP. When the used temperature is above the Ttrans, the soft segment of SMPU converts ‘active’ and increase the free volume in SMPU. This aids the transportation of more water vapor to retain the body dry and comfortable. The moisture level is also a very crucial factor which governs the comfort of clothing in addition to heat, as people can sweat both in high and low temperatures during a high degree of workload. The outcome polymeric membrane showed strong potential for textiles and packaging industrials, especially for sports wears, wound dressing and food storage, where moderate RH range is essential for human health.

Biography:

Pradeepkumar Jagadesan is currently a postdoctoral researcher at the University of Texas-San Antonio, working under Professor Kirk Schanze in the area of conjugated polyelectrolytes and organic frameworks exhibiting non-linear optical properties. Dr. Jagadesan obtained his Ph.D. from the University of Miami (UM), Florida, where he developed his expertise in the area of supramolecular photochemistry under the supervision of Professor V. Ramamurthy. Later he moved to The Ohio State University and worked as a postdoctoral researcher under Professor Psaras Mcgrier, where he synthesized the first porous organic polymer that exhibited the excited state intramolecular proton transfer (ESIPT) luminescent property. He was recently awarded the prestigious “DST-INSPIRE Faculty award” by the Ministry of Science and Technology, Government of India. During his graduate studies he was awarded the “Outstanding Teaching Award” (2015), “Perpetually Outstanding Teaching Award”(2013) and “Lifetime Teaching Assistant Award”(2011) by the department of chemistry, UM.

Abstract:

The synthesis and photophysical properties of three tris(N-salicylideneaniline) (TSA) compounds containing 1,3,5-triarylbenzene (TAB), -tristyrylbenzene (TSB), and -tris(arylethynyl)benzene (TEB) core units were studied. The TSA compounds underwent efficient excited-state intramolecular proton transfer (ESIPT) in solution and in solid state due to the preformed C=N···H_O hydrogen-bonded motifs of the structures. Steady-state fluorescence emission spectra of the TSA molecules revealed dual bands only in DMSO, and large Stokes shifts in other polar aprotic and protic solvents. Femtosecond transient absorption spectroscopic measurements in THF revealed lifetime values in the range of 14-16 ps for the excited-state keto-tautomer. The TSA compounds are also responsive to metal ions (Cu²⁺ and Zn²⁺) in DMSO and exhibit enhanced aggregate-induced emission (AIE) properties in DMSO/water mixture. Three tris(N-salicylideneaniline)-based imine-linked 2D-porous organic polymers (POPs) using the same C₃-symmetric TAB, TSB and TAE amines were synthesized that exhibit reversible type IV isotherms, which is indicative of their mesoporosity. These TSA-POPs also exhibited ESIPT emission and responsive to Cu²⁺ and Pd²⁺ making them potentially useful as fluorescent-based chemosensors

Biography:

Blessing Oseiwe Eromosele, is an Assistant Chemist, in Pydenneks offshore services limited, at NO 3, Oyinlola street, off Akowonjo Road, Lagos, Nigeria. She has graduated from our lady of Lourdes Secondary School Uromi in 2007. While she was still in College, she wrote a book on Vitamin D, and was one of the interns in grand petroleum and chemicals limited in 2011. After receiving her education, she has worked as an Assistant Chemist in Pydenneks off Shore Services Limited. She desires and embraces any opportunity that will help her build her career. She is so much interested in meeting experts face to face, learning new ideas and approaches that will make her more effective and efficient at work. She has been in her current position since February 2015 and currently, has Intern working under her

Abstract:

The use of polymeric materials has become very popular since last thirty years in many applications. A fluorine-containing elastomer comprises a terpolymer of tetrafluoroethylene, perfluoro (lower alkyl vinyl ether) and a perfluoro unsaturated nitrile compound represented by the following general formula: CF₂═CFO(CF₂)nOCF(CF₃)CN. Wherein n is an integer of 2 to 5, and a bis(amino phenyl) compound represented by the following general formula as a cross-linking agent: STR1 wherein A is an alkylidene group having 1 to 6 carbon atoms or a perfluoro alkylidene group having 1 to 10 carbon atoms and X and Y are a hydroxyl group or an amino group, can produce vulcanized products having good vulcanization physical properties and a good compression.

Biography:

Moustafa M G Fouda is currently Professor of Textile Chemistry and Technology at National Research Center, Egypt. He has earned his BSc in Chemistry at Mansoura University, Egypt (1995). His interested in the field of Science, motivated for further studies and leads him to finish his Master in Organic Chemistry at Helwan University, Egypt (1999). Along the way, he has specialized in Organic Chemistry and Textile Technology and got this expertise from National Research Center, Egypt. In 2005, he has completed his PhD in Natural Science at Duisburg-Essen Uni., Germany. He has applied his know-how technique in Medical textile applications, Nanotechnology; Synthesis, Characterization and Utilization of Metallic Nanoparticles and its Application as Antimicrobial finishing agent for cellulose based textiles and wound care managements. He authored the book “Use of Natural Polysaccharides in Medical Textile Applications”. To date, he has 60 international publications with over of 1072 citations (h-index 21) and 4 patents. He has been invited in several speaking engagements both locally and internationally. He is reviewer in several reputable international journals

Abstract:

It should now be appreciated that, there is an unmet need for a low-cost technique and chemicals as well for the production of well-stable, high concentration, green synthesized colloidal silver nanoparticles (AgNPs) having controlled size suitable for industrial applications. Starch is one of the natural polysaccharide, available, inexpensive and benign biopolymer that is used for the production of AgNPs. The challenge in this instant work is to make starch as much as soluble in cold water without any change in its morphological structure. To do such challenge, sodium form of native rice starch is prepared by the aid of alkali at room temperature. The end product is called sodium starchate that act as both well-stabilizer and reducing agent for the formed AgNPs. Characterization of AgNPs was performed using, UV-vis, TEM and EDX tools.   Silver nanoparticles of different concentrations (100, 500, 1000 and 2000 ppm) and size (6-20 nm) have been successfully prepared in one path at 60^oC in short time. Additionally, the green synthesized silver nanoparticles can be used widely in variety of health care, medicinal, and industrial antimicrobial agent for promoting healing of wounds and reducing inflammation associated with burns. Salient feature and characteristics together with unique properties would render the newly formed silver nanoparticles based products competitive in local, regional and international markets because the stability of the formed colloidal silver nanoparticles reaches for more than 2 years without any further agglomeration.