Chemistry Commons^™

An Investigation Of Poly(N-Isopropylacrylamide) For Applications With Microfluidic Paper-Based Analytical Devices, Haydn Thomas Mitchell

Master's Theses

N,N′-methylenebisacrylamide-crosslinked poly(N-isopropylacrylamide), also known as P(NIPAM), was developed as a fluid delivery system for use with microfluidic paper-based analytical devices (microPADs). MicroPADs are postage-stamp-sized devices made out of paper that can be used as platforms for low-cost, simple-to-use point-of-care diagnostic assays. P(NIPAM) is a thermally responsive polymer that absorbs aqueous solutions at room temperature and will expel the solutions to microPADs when heated. The fluid delivery characteristics of P(NIPAM) were assessed, and P(NIPAM) was able to deliver multiple solutions to microPADs in specific sequences or simultaneously in a laminar-flow configuration. P(NIPAM) was then shown to be suitable …

Improving Hybrid Solar Cells: Overcoming Charge Extraction Issues In Bulk Mixtures Of Polythiophenes And Zinc Oxide Nanostructures, Grant T. Olson

Master's Theses

Organic photovoltaics (OPVs) have received a great deal of focus in recent years as a possible alternative to expensive silicon based solar technology. Current challenges for organic photovoltaics are centered around improving their lifetimes and increasing their power conversion efficiencies. One approach to improving the lifetime of such devices has been the inclusion of inorganic metal oxide layers, but interaction between the metal oxides and common conjugated polymers is not favorable. Here we present two methods by which the interactions between polythiophenes and nanostructured ZnO can be made to be more favorable. Using the first method, direct side on attachment …

Poly (N-Isopropylacrylamide) Microgel-Based Optical Devices For Sensing And Biosensing, Molla R. Islam, Andrews Ahiabu, Xue Li, Michael J. Serpe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Responsive polymer-based materials have found numerous applications due to their ease of synthesis and the variety of stimuli that they can be made responsive to. In this review, we highlight the group’s efforts utilizing thermoresponsive poly (N-isopropylacrylamide) (pNIPAm) microgel-based optical devices for various sensing and biosensing applications.

Synthesis And Characterization Of Some Thallium Salt Complexes, Levi Dopierala

Masters Theses & Specialist Projects

Research into conductive organic and organometallic polymers began in 1977 when Heeger, Macdiarmid, and Shirakawa first doped polyacteylene with Iodine. They found that this doping granted the polymer metallic properties increasing conductivity by 11 orders of magnitude.[1] Unfortunately, polyacteylene is highly air-sensitive making it difficult to work with and limiting its applications. Therefore, current research is focused on synthesizing new organic and organometallic conductive polymers. The drive to discover these new polymers stems from their application flexibility and their low production cost.

Reported here is the synthesis of novel organometallic polymer precursors. Lead by Dr. Chad Snyder a library of …

Porphyrin Cross-Linkers For Generating Soluble Molecularly Imprinted Polymers From Polyethyleneimine, Mohammed R. Elshaer

Seton Hall University Dissertations and Theses (ETDs)

Molecular recognition is vital to many biochemical processes and is at the heart of promising bio-medically related technologies. Molecular imprinting has a long-standing history as a successful method for mimicking the molecular recognition phenomena exhibited by nature, whereby artificial receptors are prepared for a given target molecule based on synthetic polymers. The molecularly imprinted polymer (MIP) contains a three dimensional network with a memorized cavity specific to the shape and functionality of the templated target molecule. The utility of traditional MIPs has been limited due to an inherent lack of solubility. We have worked toward developing a system that allows …

Study Of The Structure-Property Relationships That Determine The Effects Of Latexes And Starch Containing Latex Emulsions On The Performance Of The Barrier Coatings (Sub-Coat) For Paper, Joanna Marie Monfils

Master's Theses

The history of carbonless paper dates back to the 1940s. Before this, a carbon copy sheet was needed between sheets of paper to be able to produce one or more copies simultaneously during writing. The pressure from a pen or typewriter would help deposit the ink of the carbon paper onto the blank sheet of paper under the original written sheet to create a “carbon copy.” This method did however, have its disadvantages. Not only did it produce a limited number of copies, but it was also a messy process. So came the creative process of using microencapsulated dyes to …

Effects Of Varying The Cure Profiles Of An Epoxy-Amine System, Patrick W. Hollingsworth

Honors Theses

The cure of an epoxy prepolymer with an amine hardener induces stress in thermosetting systems. The extent of residual stresses in the cured epoxy-amine thermosets are dependent on several factors; one of which is the cure profile utilized. The effect of cure profile on cure induced stresses of an epoxy-amine thermoset was examined in the current study. A difunctional epoxide based on diglycidyl ether of bisphenol-A (DGEBA) and a tetrafunctional amine curative were used to conduct this study. Two cure profiles were selected to prepare samples of varying degrees of stress in the cured thermosets. The first was constant heating …

Raft Polymerization Of Sulfonamide-Containing Methacrylamides, Michael B. Sims

Honors Theses

Targeted delivery of cancer therapeutics offers an exciting new opportunity for utilization of controlled polymerization techniques. However, a major obstacle in achieving the desired therapeutic effect is facilitating endosomal release of active agents following endocytosis. Peptides and pH-responsive polymers have been utilized as a means of triggering endosomal release via phase transition-induced membrane disruption. Unfortunately, the fidelity by which the pKa of these polymers/peptides can be varied is limited, such that it reduces their versatility in altering the phase transition point to best match the endosomal pH of a particular cell-type. Herein, we report the controlled polymerization of library of …

Classification Of Biorenewable Multiblock Copolymers, Sean Pickthorn

Celebrating Scholarship & Creativity Day (2011-2017)

Recent advances in polymer production sciences have led to an increase in research in sustainable practices. Our efforts intended to produce a toughened biorenewable multiblock copolymer. Polylactide has been noted to be produced by sustainable practices but is limited because of the fragile structure. To improve the brittle behavior of polylactide, preparation of polylactide-b-polybutadiene-b-polylactide multiblock copolymers were synthesized with a fixed weight of dihydroxyl polybutadiene (~3000 and ~2000g/mole series) and variable volume percent (50-90%) of both semicrystalline poly(L-lactide) and amorphous poly(D,L-lactide). Producing a multiblock copolymer intended to strengthen the mechanical properties by bridging and gapping over several domains. Initially, triblock …

Effect Of Multivalent Ions On The Swelling And Mechanical Behavior Of Superabsorbent Polymers (Saps) For Mitigation Of Mortar Autogenous Shrinkage, Qian Zhu

Open Access Theses

The chemical and physical structure-property relationships of model superabsorbent polymer (SAP) hydrogels were characterized with respect to swelling behavior and mechanical properties in different ionic solutions (Na+ , Ca2+ , and Al3+ ). The model hydrogels were composed of poly(sodium acrylate-acrylamide) (PANa-PAM) copolymer with varying concentrations of PANa (0, 17, 33, 67, and 83 wt.%) and covalent crosslinking densities of 1, 1.5, and 2 wt.%. By synthesizing the hydrogels in-house, systems with independently tunable amounts of covalent crosslinking and anionic functional groups were created, allowing for the relative effects of covalent and ionic crosslinking on the properties of the hydrogels …

Synthesis And Polymerization Of (E,E)-[6.2]-(2,5)Furanophane-1,5-Diene, Neil D. Doppler, Jeffrey H. Glans

Chemistry & Physics Faculty Publications

The goal of this research is to polymerize (E,E)-[6.2]-(2,5)furanophane to give a linear polymer. It will be synthesized by a 1,8-Hofmann Elimination using trimethyl-[(E)-3-(5-methyl-2-furyl)allyl] ammonium iodide. This diene will then be polymerized. The resulting polymeric [3.2] furanophane will then be oxidized to form a polymeric macrocycle tetra ketone. This compound will be tested for cation complexation.

Responsive Polymers For Biosensing And Protein Delivery, Molla R. Islam, Yongfeng Gao, Xue Li, Michael J. Serpe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this feature article, we review some of the most recent advances in the field of materials chemistry for biosensing, disease diagnostics, and drug delivery. Our recent work on the development of responsive polymer-based platforms for biosensing and drug delivery will also be highlighted. This feature article is meant to outline the breadth of the utility of polymer-based materials for select applications, as well as their enormous potential impact on future technologies.

Degradation Of High Voltage Glass Fiber-Reinforced Polymer Matrix Composites By Aggressive Environmental Conditions, Tianyi Lu

Electronic Theses and Dissertations

Polymer matrix composites reinforced with either E glass or ECR glass fibers-reinforced are used in a variety of high voltage electrical applications because of their advantages like lower weight and cost. However, they can be damaged by aggressive in-service conditions such as high temperature, ultraviolet radiation, moisture, ozone and corrosive environments. Different degradation mechanisms can develop in high voltage PMCs under those extreme environments, which, in turn, can affect the long term structural durability of the composites. A set of PMCs reinforced with ECR-glass and E-glass fibers embedded in four different resins has been investigated in this study. In addition, …

Dry Reforming Of Methane In Palladium-Silver-Copper Alloy Membrane Reactor, Sarocha Sumrunronnasak

Chulalongkorn University Theses and Dissertations (Chula ETD)

PdAgCu ternary alloy membranes were prepared by the sequential electroless plating of Pd following by electroplating of Ag and Cu onto stainless steel support. The metal composition of the membrane was varied by changing the metal deposition times. The fabricated membranes were then annealed at various temperatures from 500 °C to 600 °C under argon atmosphere in order to form the alloys for 20 to 120 hrs. The Energy Dispersive X-ray spectroscopy (EDX) and X-Ray Diffraction (XRD) were employed to investigate the element distribution in the membrane which provided the insight of the alloying formation. Complete formation of the alloy …

Preparation Of Polylactide/ Polycaprolactone/Hydroxyapatite Particles, Walaiporn Nguantanom

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research focused on preparation of polylactide/polycaprolactone/hydroxyapatite particles by using the solvent evaporation method. The effects of HA loadings varied in a range of 10-40 wt% and blending ratios between PLA and PCL on the size distribution, morphology, and thermal properties of the composite films were investigated. The results showed that the size distributions of the composite particles were composed of both small and large particles, depending on the HA concentration and blending ratio of PLA/PCL. The addition of HA at 10 wt% exhibited a strong influence on the size distribution of microspheres, while the PLA/PCL blend tended to produce …

Mechanical And Thermal Properties Of Polylactide/Polymeric Plasticizers, Wanlapha Apising

Chulalongkorn University Theses and Dissertations (Chula ETD)

The current study focused on flexibility improvement of polylactide by using three new types of plasticizers: diethyl succinate, glycerol ethoxylate, poly(di(ethylene glycol)adipate). The plasticizer concentrations were varied depending on each type. Mechanical property of the plasticized polymers was investigated. It was found that elongation at break of the plasticized polymers was increased, whereas tensile strength and Young’s modulus were decreased. The plasticized polymer with diethyl succinate exhibited the highest elongation at break. Thermal property of the plasticized polymers containing glycerol ethoxylate yielded the lowest Tg and Tc. When the plasticizers were added, thermal property was reduced, in which the plasticized …

Synthesis Of Poly(N-Isopropylacrylamide)-Based Nanogels Via Differential Microemulsion Polymerization For Drug Delivery Systems, Meshaya Pruettiphap

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis is to study the synthesis of poly(N-isopropylacrylamide-co-protic acid) nanogels and their performance to be used as drug delivery carriers. The objective is to achieve thermal/pH-responsive nanogels with a lower critical solution temperature (LCST) close to human body temperature. Differential microemulsion polymerization (DMP) technique, which has been considered the best one to produce nanoparticles of a high solid content with a low surfactant amount, was applied. Specifically, one-step DMP was used for synthesizing poly(N-isopropylacrylamide) (PNIPAM) preparation while two-step DMP was adopted to synthesize poly[N-isopropylacrylamide-co-(acrylic acid)] (poly(NIPAM-co-AA)) and poly[N-isopropylacrylamide-co-(itaconic acid)] (poly(NIPAM-co-IA)) nanogels, in which sodium dodecyl sulphate (SDS) was used …

Form Factor Of Pnipam Microgels In Overpacked States, U. Gasser, J. S. Hyatt, J.- J. Lietor-Santos, E. S. Herman, L. Andrew Lyon, A. Fernandez-Nieves

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We study the form factor of thermoresponsive microgels based on poly(N-isopropylacrylamide) at high generalized volume fractions, ζ, where the particles must shrink or interpenetrate to fit into the available space. Small-angle neutron scattering with contrast matching techniques is used to determine the particle form factor. We find that the particle size is constant up to a volume fraction roughly between random close packing and space filling. Beyond this point, the particle size decreases with increasing particle concentration; this decrease is found to occur with little interpenetration. Noteworthily, the suspensions remain liquid-like for ζ larger than 1, emphasizing the importance of …

Tandem Mass Spectrometry Of Multiply Charged Polymers: Using Ms3 Strategies For Full Structural Characterization Of Polyacrylamides, Paul M. Krauss

Williams Honors College, Honors Research Projects

In mass spectrometry, a compound is taken and converted into a gas-phase ion by an electrical charge (Balogh, 2009). From these ions, a chart is then created that displays the mass to charge ratio, which is able to then be analyzed to find out the charge of the ions, as well as the mass of the compound (Balogh, 2009). One specific type of mass spectrometry there is available is known as a fragmentation spectrometry. In fragmentation spectrometry, the molecule is not only ionized and analyzed, but fragmented parts that are formed into ions are also ionized and analyzed. This is …

Microwave Assisted Chemical Synthesis Using Polydimethylsiloxane, Omniya Alomainy

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Sustainable Thermoplastic Elastomers Derived From Renewable Cellulose, Rosin And Fatty Acids, Y. Liu, K. Yao, Xiaoming Chen, Jifu Wang, Zhongkai Wang, Harry J. Ploehn, C. Wang, F. Chu, Chuanbing Tang

Faculty Publications

Two series of graft copolymers, cellulose-g-poly(n-butyl acrylate-co-dehydroabietic ethyl methacrylate) (Cell-g-P(BA-co-DAEMA)) and cellulose-g-poly(lauryl methacrylate-co-dehydroabietic ethyl methacrylate) (Cell-g-P(LMA-co-DAEMA)), were prepared by “grafting from” atom transfer radical polymerization (ATRP). In these novel graft copolymers, cellulose, DAEMA (derived from rosin), and LMA (derived from fatty acids) are all sourced from renewable natural resources. The “grafting from” ATRP strategy allows the preparation of high molecular weight graft copolymers consisting of a cellulose main chain with acrylate copolymer side chains. By manipulating the monomer ratios in the P(BA- …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

Formulation Development Of A Polymer-Drug Matrix With A Controlled Release Profile For The Treatment Of Glaucoma, Eric W. Tsoi

Master's Theses

Glaucoma is the leading cause of blindness in the United States accounting for 9-12% of all cases of blindness. Currently, the front line treatment for glaucoma are prostaglandins that may have to be taken up to several times a day. Even with proper treatment, roughly 11% of the patients using the treatment are non-compliant and lose their vision. In this project, ForSight Laboratories has developed a pharmaceutical drug delivering implant with the capability of sustaining long-term release of a prostaglandin as a new way to treat the condition. This project reports the product development of a polymer drug matrix with …

Morphology And Conformation Of Polythiophene Derivatives In Anisotropic Core-Shell Nanocomposites And Solution, Neil Redeker

Master's Theses

Conjugated semiconducting polymers have garnered substantial interest in recent years due to the potential for use in various applications, particularly in the field of electronic devices such as photovoltaic cells and light emitting diodes. Conjugated polymers offer numerous advantages in these applications, including low cost and high flexibility, but electronic devices based on these materials are currently limited by poor performance. Because of these limitations, increased focus has been placed on improving conjugated polymers for use in commercially viable products. Here, a novel core shell hybrid nanocomposite based on anisotropic zinc oxide nanowires and a side-chain functionalized polythiophene is reported. …

Design And Synthesis Of Flexible And Functional Polybenzoxazine Thin Films, Austin David Baranek

Dissertations

Polybenzoxazines offer the unique ability to incorporate a variety of properties and functionality into a single polymer network through simple synthetic techniques. However, within benzoxazine materials exist certain drawbacks of which brittleness is the primary issue when exploring thin film applications. This brittleness leads to poor mechanical stability and would reduce the lifetime of any device sought after. It is, however, through the simplistic nature of the benzoxazine monomer synthesis that the mechanical stability could be addressed chemically, avoiding the complications of using rubber toughening agents or plasticizers. The monomer synthesis offers tailorability of both the phenol and amine to …

Synthesis And Characterization Of A New Cyano-Substituted Tris(Pyrazolyl)Borate And Its Thallium(I) Complex, Bozumeh Som

Electronic Theses and Dissertations

A new cyanoscorpionate - tris(4-cyano-3,5-diphenylpyrazolyl)borate (Tp^Ph2,4CN) has been synthesized and characterized. The thallium complex of this ligand TlTp^Ph2,4CN has also been prepared and characterized by FT-IR, ¹H NMR, and single-crystal X-ray-diffraction. The complex TlTp^Ph2,4CN crystalized in the monoclinic space group C2/c with unit cell a = 14.6697(10) Å, b = 13.9493(10) Å, c = 19.3347(12) Å, and b= 91.761(2)°. Structural comparison of TlTp^Ph2,4CN with analogous complexes demonstrated the effects of both steric and electron-withdrawing substituents on coordination geometry and the electronic properties of the metal ion. There were short contacts between the cyano groups …

Nanoparticles And Polymer Crystallization Kinetics In Hybrid Electronic Devices, Taylor William Wagner

Master's Theses

Conjugated semi-conducting polymers have become well known for their potential applications in hybrid electronic devices like solar cells, LEDs, and organic displays. These hybrid devices also contain inorganic nanoparticles, which complement the polymer when they are combined into the same layer. Control over the conformation and crystallinity of the polymer is critical for device performance, yet not much is known about the effect that these nanoparticles have on the polymer. Here, zinc oxide nanowire was surface modified with mono-substituted-carboxylic acid tetraphenylporphyrin and dodecanethiol, and introduced to poly(3-hexyl thiophene) in solution. The electron transfer, kinetics, and thermodynamics of this system were …

Phase Behavior And Rheology Of Latex, Thickener, Surfactant Mixtures And Liquid Crystal Based Compositions For Printing High-Efficiency Flexible Electronics, Franceska Anna Santos

Master's Theses

This project consists of two parts. One area of focus in the first part is understanding the interactions between a non-ionic, block copolymer type dispersant and hydrophobically-modified, ethoxylated urethane (HEUR) associative thickeners in water. The dispersant was mixed at various concentrations (0-2% by weight) with HEUR thickeners at 1% by weight concentration in the aqueous medium. This study is an integral part of our attempts to determine mechanisms of viscosity drop when colorant dispersions are added to latex tint base formulations thickened with associative thickeners. One of the HEUR thickeners is a product that has been available for over three …

Poly (N-Isopropylacrylamide) Microgel-Based Etalons And Etalon Arrays For Determining The Molecular Weight Of Polymers In Solution, Molla R. Islam, Michael J. Serpe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Positively and/or negatively charged poly (N-isopropylacrylamide)-based microgels were deposited on a single substrate and isolated regions of Au overlayers were deposited on top of the microgels. Each spatially isolated Au overlayer region had a different thickness to make an etalon array.We found that areas with a thin Au overlayer (5 nm) responded to a range of polymer molecular weights (MW), while areas with a thick overlayer (35 nm) can only respond to low molecular weight polyelectrolytes. By comparing the optical responses of the device’s individual array elements, a good approximation of the polyelectrolyteMWin solution can be made.

Synthesis Of Environmentally-Friendly Polyurethane Dispersions Based On Soybean Oil- Derived Polyols And Their Applications In Advanced Water-Based And Uv-Cure Coatings, Senthikumar Rengasamy

Master's Theses and Doctoral Dissertations

Polyurethane dispersions (PUD) have established themselves as most versatile polymeric binder in coating, adhesive, sealant, and elastomer industries. Like any other polymers, PUDs also have certain limitations, such as hydrolytic stability, water resistance, and oil resistance. In order to develop these properties, two different polyol families were synthesized. The first polyol can be used in ambient curable systems, and the second can be utilized in ultraviolet radiation cure coatings. For ambient curable systems polyether chemistry based soy-polyol was developed from epoxidized soy fatty acid methyl ester (ESFAME). The cationic ring opening of oxirane oxygen groups from ESFAME resulted in polyol …