Chemistry Commons^™

Preparation Of Starch-Filled Polyisocyanurate Foams Catalyzed By Zinc-Ammonia Complex/Potassium Octoate, Sirima Goonack

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research aimed to reduce apparent density and improve fire resistance of polyisocyanurate (PIR) foam. PIR foams were prepared using zinc-ammonia complex and potassium octoate as catalyst for gelling/blowing and trimerization reactions, respectively. Three types of starch produced in Thailand, namely glutinous rice flour, rice flour and mung bean starch, were used as additives for PIR foams. The characterized properties of PIR foams modified with starches are reaction times (cream time, gel time, rise time and tack free time), polyisocyanurate/polyurethane (PIR/PUR) ratio, %isocyanate conversion, apparent density, compressive property, morphology and fire behavior. These properties are compared with PIR foam without …

Magnetic Nanoparticles Stabilized By Phosphorylcholine-Containing Polymer For Antibody Free C-Reactive Protein Detection, Suttawan Saipia

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to develop a simple, yet effective assay for C-reactive protein (CRP) detection based on a combination of magnetic separation and antibody-free colorimetric assay. Magnetic nanoparticles stabilized with phosphorylcholine-containing polymer, poly[methacrylic acid)-ran-(methacryloyloxyethyl phosphorylcholine)] (PMAMPC-MNPs) were prepared by co-precipitation of ferric and ferrous salts in the presence of PMAMPC. Carboxyl groups in the methacrylic acid (MA) repeat units chelate with Fe atoms during MNPs formation while the methacryloyloxyethyl phosphorylcholine (MPC) repeat units provide specifically binding sites and conjugate with CRP in presence of Ca2+. The PMAMPC-MNPs were characterized by ATR-FTIR, TEM, DLS, TGA and XRD. To determine the CRP …

Electrospun Nylon 6,6 Nanofibers Functionalized With Β-Cyclodextrin As Solid Phase Extraction Sorbent For Determination Of Parabens, Tassanee Kuakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, electrospun nanofibers of nylon 6,6 functionalized with β-cyclodextrin (nylon 6,6/β-CD) were fabricated and applied as a sorbent in solid-phase extraction (SPE) for determination of parabens in water. The electrospinning parameters such as polymer concentration, nylon 6,6/β-CD ratio, and electric field strength were investigated in order to obtain uniform nanofibers. The morphology and physical properties of obtained fibers were characterized by scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), and BET surface area analysis. The electrospun nylon 6,6/β-CD nanofibers were achieved with diameter in the range of 120 - 150 nm. The additional of β-CD slightly increased …

High Magnification Polymeric Lens For Smartphone Microscope, Wisansaya Jaikeandee

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, we present a facile method for fabrication of plano-convex lenses, using high reflective optical polymer (Polydimethylsiloxane, Sylgard 184 by Dow Corning, n ~1.42 and Norland Optical adhesive 61, NOA61 by Norland Products, ~1.56) under the confined sessile drop technique. The confined sessile drop technique is a facile method and an adjustable lens geometry through controlled the weight of liquid polymer on the lens substrate, as PMMA circular disk and Sylgard circular disk, with different diameter (2.5-6.0 mm). The liquid polymer was gradually spread and radially over the surface of the lens substrate, and resistance to spreading of …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Electropolymerization Of Polyaniline In The Presence Of Ferricyanide: Electrochemical, Spectroscopic And Gravimetric Studies, Lucas Marinelli

Master's Theses

In this work, ferricyanide-doped polyaniline (PANI) is electropolymerized by constant current and cyclic voltammetry (CV) measurements with simultaneous monitoring of mass changes using electrochemical quartz crystal microbalance (eQCM). Raman spectroscopy, Fourier transform infrared spectroscopy and CV measurements confirm the incorporation of the ferricyanide into the film and indicate modified electrical conductivity. UV-Vis absorbance spectroscopy and Raman spectroscopy confirm the conducting ‘emeraldine-salt’ state and confirm the presence of polarons, i.e. charge carriers.

The addition of ferricyanide during electropolymerization of the PANI film results in an increase of polymerization rate as confirmed using eQCM. A decrease in counter ion ingress/egress and an …

Combination Therapy: Parp Inhibitor Synergizes The Therapeutic Efficacy Of Doxorubicin In The Treatment Of Prostate Cancer, Momin Ansare

Electronic Theses & Dissertations

Men are most susceptible to prostate cancer in the United States. The general treatment options include surgery, hormone therapy, chemotherapy, and radiation therapy. But in recent days, the nanoformulation have shown promising applications in overcoming the drawbacks of the currently available treatment options. To complement, we tried to enhance the capability of the nanoparticle formulation by loading them with a novel drug combination for the treatment of prostate cancer. Herein, we synthesized folate conjugated iron oxide nanoparticles encapsulated with doxorubicin and olaparib for imaging and targeted treatment of prostate cancer. Both drugs are approved by FDA for clinical cancer treatment. …

Synthesis Of Doxorubicin-Based Prodrug And Activatable Mr Nanoprobe For The Imaging And Treatment Of Cancer, Bayan Dous

Electronic Theses & Dissertations

Magnetic Resonance Imaging (MRI) is increasingly being used as a diagnostic tool for cancer. We propose a novel molecular probe, Gadolinium-DTPA disulfide-bonded Doxorubicin (Gd-DTPA-SS-Doxo) encapsulated in iron oxide which could provide a dual modality for detecting malignant growth while simultaneously targeting treatment options. We first synthesized Gd-DTPA-SS-Doxo followed by encapsulation within the poly (acrylic acid) (PAA) coating of iron oxide nanoparticle (IONP), producing a nanoprobe (IO-Gd-DTPA-SS-Doxo) with quenched longitudinal spin lattice magnetic relaxation (T1). After receptor-mediated internalization, Gd-DTPA-SS-Doxo is released from the nanoprobe’s polymeric coating due to the acidic microenvironment of the tumor. When the molecular probe is subjected to …

A New Generation Of Functional Polyisobutylenes For Advanced Applications, Corey M. Parada

Dissertations

Polyisobutylene (PIB) is a fully saturated, aliphatic polymer of high commercial importance due to its superior gas barrier properties and high chemical/oxidative stability. One commercial end-use for PIB is in insulated glass windows (IGU), where it acts as a gas/moisture barrier and sealant. Under certain adverse conditions, catastrophic failure of the PIB sealant may result in aesthetic and functional failure of the IGU, which necessitates replacement of the unit. Thus, there exists a need to improve current generations of thermoplastic PIB sealants to be able to withstand the harsh environments found in current real-world applications.

In the first project, we …

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …

Effect Of Network Structure On Free Volume And Gas Transport Properties Of Thiol-Ene And Epoxy-Amine Networks, Ramesh Krishnan Ramakrishnan

Dissertations

Network parameters such as cross-link density or intermolecular interactions were used as effective parameters to control polymer chain packing or free volume and thereby control the mass transport properties of networks.

A series of polyethylene glycol (PEG) based thiol-ene elastomeric networks having a broad range of molecular weight between cross-links, M_c, (inverse of cross-link density) was prepared. The specific volume of the networks was studied as a function of temperature and pressure using high pressure dilatometry, and the obtained PVT data was fit using Simha-Somcynsky equation of state (S-S eos) analysis. Fractional free volume, quantified through S-S eos …

Structure-Property Relationships Of Solvent-Cast Organic Thin Films For Model Corrosion Control Coatings, Austin Maples

Dissertations

This dissertation aimed at answering several fundamental questions, specifically: 1) What is the effect of scribing parameters on visual corrosion assessments? 2) What role do molecular weight, residual solvent, and polymer composition have on morphological changes in organic thin films? 3) What alternatives to visual assessments could be implemented to better understand and detect corrosion before macroscopic failure? This research definitively proved that scribes can vary in type and dimensions, and yet are still comparable if the scribe dimensions before exposure are known. Furthermore, it demonstrated that solvents common to a variety of coating industries could become trapped within the …

Influence Of High Aspect Ratio Nanoparticle Filler Addition On Piezoelectric Nanocomposites, Jeremy A. Armas

Master's Theses

Piezoelectric nanogenerators (PNGs) are a new class of energy harvesting materials that show potential as a direct energy source for low powered electronics. Recently, piezoelectric polymers have been utilized for PNG technology due to low toxicity, high flexibility, and facile solution processing which provide manufacturing opportunities such as screen printing. Throughout the last decade, countless projects have focused on how to enhance the energy harvesting capabilities of these PNGs through the incorporation of nanoparticle fillers, which have been reported to enhance the piezoelectric properties of the film either directly through their intrinsic piezoelectric properties or through acting as surfaces for …

High-Throughput Assessment Of A Novel, Thiol-Acrylate Hydrogel For Tumor Spheroid Synthesis In A Microfluidic Device, Nathan Daniel Kersker

LSU Master's Theses

The extracellular environment plays an important role in regulating cell behavior. The mechanical, structural, and compositional properties of the extracellular matrix can determine the fate of the growing cells. Standard two-dimensional culturing in a flask fails to represent a native cellular environment. To create the native environment suitable for cells, hydrogels were previously studied. One of the most extensively studied synthetic hydrogels was a poly(ethylene glycol diacrylate) (PEGDA) hydrogel. However, the need for UV polymerization may introduce unwanted changes in cell morphology and viability. The hydrogel being proposed was a form of a thiol-acrylate hydrogel that can eliminate this problem …

Unexpected Effects Of Inorganic Phosphate Glass On Crystallization And Thermo-Rheological Behavior Of Polyethylene Terephthalate, Kyoungtae Kim, Shahab Kashani Rahimi, Todd M. Alam, Eric G. Sorte, Joshua U. Otaigbe

Faculty Publications

The effects of ultra-low glass transition temperature (T_g) phosphate glass (Pglass) on the thermal, morphological, rheological, mechanical, and crystallization properties of hybrid Pglass/poly(eththylene terephthalate)(PET) were investigated. Nano- and micro-scale distribution of the Pglass in the PET polymer matrix was observed. The polydispersed Pglass in the PET matrix functioned as a nucleation agent, resulting in increasing crystallization temperature. The Pglass in the PET matrix decreased the T_g, indicating a plasticizing effect of the Pglass in the hybrids that was confirmed by the significantly decreased complex viscosity of the PET matrix. In addition, with increasing temperature, a non-terminal …

Isolation Of Rna From A Mixture And Its Detection By Utilizing A Microgel-Based Optical Device, Molla R. Islam, Shakiba Azimi, Faranak Teimoory, Glen Loppnow, Michael J. Serpe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this investigation, we show that RNA can be separated from a solution containing DNA and RNA and the isolated RNA can be detected using poly (N-isopropylacrylamide-co-N-(3-aminopropyl) methacrylamide hydrochloride) microgel-based optical devices (etalons). The isolation of RNA was accomplished by using hairpin-functionalized magnetic beads (MMPDNA) and differential melting, based on the fact that the DNA–RNA hybrid duplex is stronger (i.e., high melting temperature) than the DNA–DNA duplex (i.e., low melting temperature). By performing concurrent etalon sensing and fluorescent studies, we found that the MMPDNA combined with differential melting was capable of selectively separating RNA from DNA. This selective separation and …

Iron Oxide Nanomagnets In Polymer Matrices – Synthesis And Characterization, Shenjie Qiu

Dissertations, Theses, and Capstone Projects

Magneto-responsive polymer-iron oxide materials have been fabricated by coating various polymers on iron oxide nanoparticles (NPs). The stability of magneto-responsive polymer-iron oxide materials relies on the selection of appropriate coating anchors, such as catechols and silanes. This dissertation describes two robust polymer coating systems on iron oxide NPs. One system focuses on thermo-responsive nitrated catechol-N-isopropylacrylamide polymers with binding enhancement factors (EnF) of ~40 and ~20 towards iron oxide NPs and a boronic acid compared to the polymers without the nitro group. The second system involves coating of poly(vinyl alcohol) (PVA) on iron oxide NPs via a silane anchor …

Flexible And Versatile Soft Templates For Mesoporous Silicas And Organosilicas Based On Pluronic Block Copolymer Surfactants And Their Mixtures, George Farid

Dissertations, Theses, and Capstone Projects

In this dissertation, the work will be discussed that was focused on the synthesis of consolidated periodic mesoporous materials such as 2-D hexgonal ordered mesoporous silicas (SBA-15) as well as single-micelle-templated silica and organosilica nanotubes and nanospheres using triblock copolymer surfactants and their mixtures in the presence of a swelling agent. The introductory section, Chapter 1, will address the current state of the tunability of single-micelle-templated silica and organosilica nanotubes and will compare it with the work presented in this dissertation on the use of a dual-surfactant templating systems. Chapter 2 of the dissertation discusses transmission electron microscopy characterization of …

Sintering-Induced Nucleation And Growth Of Noble Metal Nanoparticles For Plasmonic Resonance Ceramic Color, Nathan Dinh, Michael C. Leopold, Ryan Coppage

Chemistry Faculty Publications

This study demonstrates the formation of nanoparticles (NPs) from metal salts within ceramic glazes, such that the use of this colorant technology is more accessible to artisans, employs less metal content, is less environmentally harmful, and allows for the use of traditional kilns. Gold NPs have been demonstrated to possess a specific, low material loading use as a ceramic glaze colorant via plasmon resonance. Pre-synthesized gold NPs that are added to ceramic glazes have been found to significantly change in size after firing in both reductive and oxidative atmospheres, but still maintain some size relationships and color properties. Unfortunately, it …

Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential …

Applications Of Diels-Alder Chemistry In Polymer Synthesis, Joshua C. Stambaugh, Philip J. Costanzo, Sierra E. Gosting

STAR Program Research Presentations

Diels-Alder chemistry is utilized for a myriad of commercial applications during polymer synthesis, ranging from self-healing materials to heat responsive materials to emulsion coatings. In particular, the ability to regulate and control the amount and type of functional group linkages is key component for polymer applications. A common strategy that is employed is the use of phenolic maleimide as a dienophile during Diels-Alder synthesis to control the linkages on a polymer, which determines its properties and functionality. This summer was the beginning of a project to prepare a commercial scale, water-based emulsion floor coating/polish. The first step in this project …

Synthesis And Characterization Of Block Copolymers For Shear Force Responsive Materials And Sugar Conjugated Fluorescent Probes, Jacob Ryan Blankenship

Graduate Theses/Dissertations

Herein, I present my work towards two goals: shear force-responsive materials and sugarconjugated fluorescent probes for bacterial identification applications. The first work is on the development of stimuli-responsive polymers that allow for precise control over the release of encapsulated material. Stimuli-responsive polymers are becoming increasingly important in drug delivery and other applications. However there have been few reports on shear force-responsive micellar systems. I show the synthesis, and characterization by ¹H and ¹³C NMR of four macro-chain transfer agents (macro-CTAs), one of which has not been previously reported. The resulting macro-CTAs were used in polymerization of vinyl acetate …

New Insights Into The Design Of Conjugated Polymers For Intramolecular Singlet Fission, Jiahua Hu, Ke Xu, Lei Shen, Qin Wu, Guiying He, Jie-Yu Wang, Jian Pei, Jianlong Xia, Matthew Y. Sfeir

Publications and Research

Singlet fission (SF), a multiple exciton generation process that generates two triplet excitons after the absorption of one photon, can potentially enable more efficient solar cell designs by harvesting energy normally lost as heat. While low-bandgap conjugated polymers are highly promising candidates for efficient SF-based solar cells, few polymer materials capable of SF have been reported because the SF process in polymer chains is poorly understood. Using transient spectroscopy, we demonstrate a new, highly efficient (triplet yield of 160-200%) isoindigo-based donor–acceptor polymer and show that the triplet pairs are directly emissive and exhibit a time-dependent energy evolution. Importantly, aggregation in …

Development Of Mof@Polymer Composite Materials Through Bottom-Up Self-Assembly Techniques, Roberto Christian Arbulu

Chemistry and Chemical Biology ETDs

MOF-based mixed matrix membranes (MMMs) are a promising new class of MOF/polymer composite materials. Currently, fabrication of MMMs is based on top-down methods with limited control over MOF positioning, integration, or morphology. This work focuses on the growth of well-defined one-dimensional (1-D) MOF nanostructures within the pores of a nanoporous polymer template, either commercially available or through the self-assembly of block co-polymers having tailor-designed surface functionalities. Studies were conducted using zeolitic imidazole framework-8 (ZIF-8) and polycarbonate track etched (PCTE) membranes, which demonstrated the feasibility of the outlined approach, and revealed the formation of distinct super- and nanostructures with controlled morphologies …

Mini‐Review: The Promise Of Piezoelectric Polymers, Timothy D. Usher, Kimberley R. Cousins, Renwu Zhang, Stephen Ducharme

Physics Faculty Publications

Recent advances provide new opportunities in the field of polymer piezoelectric materials. Piezoelectric materials provide unique insights to the fundamental understanding of the solid state. In addition, piezoelectric materials have a wide range of applications, representing billions of dollars of commercial applications. However, inorganic piezoelectric materials have limitations that polymer ferroelectric materials can overcome, if certain challenges can be addressed. This mini-review is a practical summary of the current research and future directions in the investigation and application of piezoelectric materials with an emphasis on polymeric piezoelectric materials. We will assume that the reader is well versed in the subject …

Thermosetting Polymers Via Azide Alkyne Cycloaddition, Richard H. Cooke Iii

Dissertations

This dissertation exploits properties inherent to azide-alkyne cycloaddition and applies practical solutions to difficult problems. Chapter II addresses structure-property relationships in glassy azido-alkyne matrices by varying the identity of the central linkage within tetrapropargyl bis-aniline-type crosslinkers, and by the addition or omission of Cu(I) catalyst. This systematic study showed that an ether or methylene linkage yielded lower melting tetrapropargyl crosslinkers that were soluble in, and produced homogeneous, networks when cured with, a standard azido resin, di(3-azido-2-hydroxypropyl) ether of bisphenol-A; in contrast, a sulfone linkage yielded a relatively insoluble crosslinker and poorly dispersed, heterogeneous networks when reacted with the same …

The Effect Of Soxhlet Extraction And Synthesis Temperature On Properties Of Polyaniline, Samuel Watson Stahl

Chemistry & Biochemistry Theses & Dissertations

Polyaniline was synthesized by the chemical oxidation of aniline in an HCl solution by ammonium persulfate. The temperature of the synthesis was varied to increase the molecular weight of the polymer from 37,600 Da to 52,400 Da. Soxhlet extraction using methanol as the primary solvent was performed on half the sample in order to further increase the average molecular weight by approximately 3150 Da and decrease the polydispersity index by 0.8. Films were cast from 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) and N-methyl-2-pyrrolidone (NMP) and then doped with trifluoromethanesulfonic acid.

The effect of the soxhlet extraction and synthesis temperature on the polymer’s properties …

An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer, Sukwoo Jung, Hangyeol Kim, Junseok Ahn

The International Student Science Fair 2018

In this research, an entirely new molecular glue is reported. This ‘coordination polymer glue’ is synthesized from zinc metal and BDC-NPE(2,5-bis{4-[1-(4-nitrophenyl)ethylamino]butoxy}terephthalic acid). Molecular glue transforms from 1D coordination polymer to a 3D cross-linked framework, resulting in a phase change of solution to solid. The carboxylate group of this glue makes the preformed MOF bind to its framework. Therefore, when the solution of molecular glue is mixed with preformed MOF powder and heated, homogeneous and thin MOF film – MOF/ZnNPE film – is fabricated. The film is irrelevant to the kind of its substrate, and its thermal stability was enhanced in …

Glucosamine From Hydrolysis Of 3d Printing Chitosan For Osteoarthritis Treatment, Ruj Dansriboon, Laphon Premcharoen

The International Student Science Fair 2018

This project aims to introduce a new way for osteoarthritis treatment which is expected to increase in the future. Glucosamine is the main subject for a treatment, which can be derived by hydrolyzing chitosan. This project also includes extraction of chitosan from shrimp waste to make a worthy use of food waste from industry. In this project, 3D printer is applied to print chitosan gel since 3D printing is adjustable to form various shapes of the gel.

The research process begins with the extraction of chitosan from shrimp shells. For the next step, the percent of deacetylation of chitosan was …

An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer, Sukwoo Jung, Hangyeol Kim, Junseok Ahn

The International Student Science Fair 2018

In this research, an entirely new molecular glue is reported. This ‘coordination polymer glue’ is synthesized from zinc metal and BDC-NPE(2,5-bis{4-[1-(4-nitrophenyl)ethylamino]butoxy}terephthalic acid). Molecular glue transforms from 1D coordination polymer to a 3D cross-linked framework, resulting in a phase change of solution to solid. The carboxylate group of this glue makes the preformed MOF bind to its framework. Therefore, when the solution of molecular glue is mixed with preformed MOF powder and heated, homogeneous and thin MOF film – MOF/ZnNPE film – is fabricated. The film is irrelevant to the kind of its substrate, and its thermal stability was enhanced in …