Polymer Chemistry Commons^™

Identification Of Crude Palm Oils By The Analyses Of Fatty Acids, Volatile Organic Compounds, And Carotenoids, Somluk Sanorkham

Chulalongkorn University Theses and Dissertations (Chula ETD)

An in-depth analysis of crude palm oil is important to differentiate crude palm oil (CPO) from different geographic provenance for administrative control purposes to prevent and solve the problem of smuggling CPO from abroad to Thailand. In this study, eleven CPO samples from five provinces in Thailand were studied for their composition. The compositions of fatty acids, volatile organic compounds (VOCs), and carotenoids were characterized by GC-FID, GC-MS, and HPLC-DAD techniques, respectively. The chromatograms of fatty acids distribution were similar for all samples. The main components of fatty acids are palmitic acid, oleic acid, linoleic acid, and stearic acid. In …

Silver Surface Enrichment On Zsm-5 Zeolites For The Catalytic Cracking Of N-Pentane To Produce Light Olefins, Warisara Angguravanich

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effects of Ag-incorporation on the catalytic performance of ZSM-5 zeolites have been investigated. Since Ag-incorporation can promote the formation of light olefins and significantly enhance catalytic performance in n-pentane catalytic cracking. However, the Ag-incorporated ZSM-5 zeolite was rapidly deactivated in npentane catalytic cracking. Thus, CLD and sulfation methods were introduced to improve catalytic activity and stability of Ag-incorporated ZSM-5 zeolites. The Agincorporated ZSM-5 zeolites have been prepared by the incipient wetness impregnation and CLD methods. Moreover, the sulfated catalyst was prepared by the sequential CLD and sulfation of commercial HZSM-5 zeolite. The catalytic activity and stability of Ag-incorporated ZSM-5 …

กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์จากคอปเปอร์ออกไซด์/รีดิวซ์กราฟีนออกไซด์นาโนคอมพอสิต, นพรัตน์ จันทร์มี

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในงานวิจัยนี้กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ถูกพัฒนาขึ้นโดยใช้นาโนคอมพอสิตของโลหะออกไซด์และรีดิวซ์กราฟีนออกไซด์ ขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนถูกดัดแปรด้วยรีดิวซ์ กราฟีนออกไซด์เพื่อเพิ่มการนำไฟฟ้าและดัดแปรด้วยโลหะออกไซด์ที่มีขนาดในระดับนาโนสองชนิด ได้แก่ คอปเปอร์ออกไซด์ และซิงค์ออกไซด์เพื่อเป็นตัวเร่งทางเคมีไฟฟ้าสำหรับการเกิดออกซิเดชันโดยตรงของกลูโคส โดยศึกษาความเข้มข้นของสารดัดแปรที่เหมาะสมด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด จากนั้นเปรียบเทียบประสิทธิภาพการเร่งปฏิกิริยาของขั้วไฟฟ้าดัดแปรด้วยโลหะออกไซด์ด้วยเทคนิคไซคลิกโวล แทมเมทรีพบว่าขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วยรีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์ให้กระแสสูงสุด จึงเลือกมาใช้เป็นขั้วไฟฟ้าสำหรับกลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ สำหรับการตรวจวัดกลูโคสในตัวอย่างจริง อุปกรณ์รูปแบบใหม่ถูกสร้างขึ้นโดยติดกระดาษพิมพ์แวกซ์ที่เคลือบด้วยโซเดียมไฮดรอกไซด์เพื่อเป็นส่วนป้อนสารตัวอย่างลงบนขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วย รีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์ อุปกรณ์นี้ถูกใช้ตรวจวัดกลูโคสในฟอสเฟตบับเฟอร์ซาลีนแสดงช่วงความเป็นเส้นตรงที่ 0.125 ถึง 7.0 มิลลิโมลาร์ และ 0.031 ถึง 7.0 มิลลิโมลาร์ โดยมีค่าสัมประสิทธิ์สหสัมพันธ์ที่ 0.9940 และ 0.9911 สำหรับการตรวจวัดด้วยเทคนิคไซคลิกโวลแทมเมทรีและเทคนิคแอมเพอโรเมทรี ตามลำดับ นอกจากนี้ขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วยรีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์สามารถคงประสิทธิภาพการตรวจวัดได้ถึง 6 วันภายหลังการเตรียมอุปกรณ์ กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ที่พัฒนาขึ้นนี้จึงสามารถประยุกต์เป็นอุปกรณ์ทางเลือกสำหรับติดตามผู้ป่วยโรคเบาหวานอย่างง่ายโดยไม่ต้องเตรียมตัวอย่าง

A Theoretical And Experimental Study Of Charge Transport In Organic Thermoelectric Materials And Charge Transfer States In Organic Photovoltaics, Ashkan Abtahi

Theses and Dissertations--Physics and Astronomy

Applications of organic electronics have increased significantly over the past two decades. Organic semiconductors (OSC) can be used in mechanically flexible devices with potentially lower cost of fabrication than their inorganic counterparts, yet in many cases organic semiconductor-based devices suffer from lower performance and stability. Investigating the doping mechanism, charge transport, and charge transfer in such materials will allow us to address the parameters that limit performance and potentially resolve them. In this dissertation, organic materials are used in three different device structures to investigate charge transport and charge transfer. Chemically doped π-conjugated polymers are promising materials to be used …

A Proposed Mechanism To Induce Multi-Layer Polydiacetylene-Coated Filter Color Response To Bacteria , Timothy Hanks

Chemistry Publications

The purpose of this study was to develop a multi-layer diacetylene (PDA)-coated filter and to verify the proposed color response mechanism of PDA-coated filters to bacteria. Unlike other reports which immobilize PDA lipo- somes on solid support or create monolayer Langmuir films, multi-layer PDA-coated filters were generated by directly evaporating organic solvents. Different from incorporating functional headgroups or inserting phospho- lipids into PDA, we reported that bacterial growth can trigger the color change of PDA sensors without any mod- ification or phospholipid insertion. The mechanism that pH change from bacteria metabolites lead to color change of PDA filter was proposed …

Hypervalent Iodine Compounds With Carboxylate And Tetrazolate Ligands, Avichal Vaish

Chemistry Theses and Dissertations

In modern organic chemistry, hypervalent (HV) iodine(III) compounds are frequently used as oxidizing agents but application of λ³-iodanes in polymer and material chemistry is still underexplored. This dissertation describes the preparation of dynamic and self-healing materials by employing ligand exchange reactions involving HV iodine(III) compounds of the type ArIL₂ (Ar = Aryl, L = ligand, e.g., carboxylate or (pseudo)halide). These compounds can undergo ligand exchange reactions in presence of nucleophiles (Nu^-) to form ArINu₂. Diacetoxyiodo benzene was successfully employed as a crosslinker to prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore, …

Polyarylenes: Synthesis And Characterization Towards Advanced Applications, Stephen Budy

Chemistry Theses and Dissertations

A series of semi-fluorinated and non-fluorinated Diels−Alder step-growth polyarylene polymers and co-polymers were synthesized via typical oil bath heating (days/weeks) and more rapid microwave-assisted polymerization (hours). The polymers were characterized by multi-nuclear (¹H, ¹³C, and ¹⁹F) NMR and ATR−FTIR spectroscopy, thermal analysis (TGA, DSC, and DMA), GPC, XRD, water contact analysis (WCA), and refractive index (RI) measurements. The NMR spectra indicated a mixture of para and meta conformations through the polymer backbone increasing to more para with greater fluorine content. Thermal gravimetric analysis revealed the fluorine-containing polyarylenes possessed the highest char yields at almost 80% at …

Greening Of Catalytic Processes Using First-Row Transition Metals For Atom Transfer Radical Addition And Transfer Hydrogenation, Gabrielle Pros

Electronic Theses and Dissertations

This work focused on “greening” catalytic processes, atom transfer radical addition (ATRA), which adds an alkyl halide across and alkene, and transfer hydrogenation/dehydrogenation, which reduces a carbonyl without needing direct H₂ gas. Part of “greening” of these processes is through using abundant first row metals, Cu and Ni for catalysis. One aim was to design new ligands which would be more active in these systems; the second was investigation of additives for catalyst regeneration to reduce the catalyst loading necessary for high yields.

The TPMA^* family was investigated in ATRA. Rate constants followed the expected trend, which increased …

Influencing Factors On The Velocity And Temperature Of Propagating Fronts In Acrylate Composites, Samuel Morris Bynum

LSU Doctoral Dissertations

Thermal frontal polymerization is a type of polymerization in which a localized reaction zone propagates through an unstirred system. It is incumbent upon the production and transport of heat produced as a result of the exothermic reaction associated with free-radical polymerization. First discovered in the 1970s, frontal polymerization has been since utilized to produce a variety of different materials, utilizing a variety of different chemistries. The temperature of the propagating front and the velocity at which it propagates can be influenced via chemical or physical means. We show that through careful selection of monomers and control of the concentration of …

Adsorption Of Polyisobutylene-Based Dispersants Onto Carbon Black, Travis Paul Holbrook

Dissertations

The formation of carbonaceous by-products (e.g. soot) during the operation of an internal combustion engine is unavoidable and the aggregation of this soot leads to deleterious effects including abrasive wear of the engine, increased oil viscosities, and sludge deposition. Dispersants, which are composed of a hydrophobic tail and a polar headgroup, are used as oil additives to aid in the suspension and stabilization of the soot particles. Polyisobutylene succinimide (PIBSI) is the most well-studied class of dispersants and is characterized by a linear architecture and polyamine headgroup that interacts with soot by acid-base and dipole-dipole interactions. As such, there remains …

The Antimicrobial Activity And Cellular Targets Of Plant Derived Aldehydes And Degradable Pro-Antimicrobial Networks In Pseudomonas Aeruginosa, Yetunde Adewunmi

Dissertations

Essential oils (EOs) are plant-derived products that have been long exploited for their antimicrobial activities in medicine, agriculture, and food preservation. EOs represent a promising alternative to conventional antibiotics due to the broad-range antimicrobial activity, low toxicity to human commensal bacteria, and the capacity to kill microorganisms without promoting resistance. Despite the progress in the understanding of the biological activity of EOs, many aspects of their mode of action remain inconclusive. The overarching aim of this work was to address these gaps by studying molecular interactions between antimicrobial plant aldehydes and the opportunistic human pathogen Pseudomonas aeruginosa. We initiated …

Towards Completely Automated Glycan Synthesis, Matteo Panza

Dissertations

Carbohydrates are ubiquitous both in nature as biologically active compounds and in medicine as pharmaceuticals. Although there has been continued interest in the synthesis of carbohydrates, chemical methods require specialized knowledge and hence remain cumbersome. The need for development of rapid, efficient and operationally simple procedures has come to the fore. This dissertation focuses on the development of a fully automated platform that will enable both experts and non-specialists to perform the synthesis of glycans. Existing automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) …

Modeling And Simulations Of Peptoids, Pu Du

LSU Doctoral Dissertations

Polypeptoids, or poly-N-substituted glycines, are a class of sequence defined polymers that are structural mimics of polypeptides. Polypeptoids currently have received a growing interest due to their improved thermal stability, larger chemical diversity, and easier synthetic pathways as compared to peptides. Their lack of backbone hydrogen bonding and stereochemistry coupled with their easily tunability make them an ideal prototypical model system to study the effect of secondary/non-covalent interactions on self-assembly in solution. In order to develop a molecular level understanding of the effect of secondary interactions on polypeptoid self-assembly, systematic studies were carried out using molecular dynamics simulations on several …

Hierarchical Conjugated Polymer Systems Prepared By Controlled Chain-Growth Polymerization, Chunwa Peter Kei

LSU Doctoral Dissertations

π-Conjugated polymer materials may have a significant economic impact on society by providing means for designing affordable, flexible, and portable organic electronic devices. Their successful commercialization will depend on major scientific advancements, which will challenge human society to seek out ever more detailed and fundamental processes to command. Controlled polymerization affords such a power; allowing for the design of meticulous and precisely defined systems granting detailed insight into structure-property relationships in the polymer materials and bettering understanding of novel physical phenomena.

This dissertation primarily focuses on development and preparation of well-defined hierarchically organized macromolecular systems. The novel chain-growth polymerization methodologies …

Structure-Property-Function Connections Underlying Performance Of Polybenzoxazole Membranes Derived From Bisapaf Polyimides, Maram A. Q. Al-Sayaghi, Jeremy Lewis, Chris Buelke, Ali Alshami

Chemical Engineering Faculty Publications

Highlights

• Stable rigid monomers result in polyimides with higher Mw, Tg, TR, and the more superior separation performance.
• Thermal rearrangement improved ideal gas separation by 1.5 to 2.0 orders of magnitude.
• Thermal rearrangement resulted in an enhanced thermal, mechanical and chemical properties of the produced membranes.

Polymeric membranes remain and will most likely continue to be the most practical cost-effect chemical constructs for gas separation processes, provided that novel polymers are developed to overcome current and persisting limitations facing exiting membranes. Here, we report a methodical and systematic study of the structure-property-function relations of standard polyimide membranes and their implications …

Stretchable Self-Healable Semiconducting Polymer Film For Active-Matrix Strain-Sensing Array, Jin Young Oh, Donghee Son, Toru Katsumata, Yeongjun Lee, Yeongin Kim, Jeffrey Lopez, Hung-Chin Wu, Jiheong Kang, Joonsuk Park, Xiaodan Gu, Jaewan Mun, Nathan Ging-Ji Wang, Yikai Yin, Wei Cai, Youngjun Yun, Jeffrey B.-H. Tok, Zhenan Bao

Faculty Publications

Skin-like sensory devidces shoud be stretchable and self-healable to meet the demands for future electronic skin applications. Despite recent notable advances in skin-inspired electronic materials, it remains challenging to confer these desired functionalities to an active semiconductor. Here, we report a strain-sensitive, stretchable, and autonomously self-healable semiconducting film achieved through blending of a polymer semiconductor and a self-healable elastomer, both of which are dynamically cross-linked by metal coordination. We observed that by controlling the percolation threshold of the polymer semiconductor, the blend film became strain sensitive, with a gauge factor of 5.75 x 10⁵ at 100% strain in a …

Formulation To Application: Thermomechanical Characterization Of Flexible Polyimides And The Improvement Of Their Properties Via Chain Interaction, Alejandro Rivera Nicholls

USF Tampa Graduate Theses and Dissertations

In this work, Polyimides were synthesized by incorporating an aromatic diamine monomer with a methylene linker, 4,4'-methylenebis(2,6-dimethylaniline) (MBDMA), to make a robust main chain along with aliphatic polyetherdiamine backbone linkers to reduce rigidity. The polymers were designed to exhibit thermal properties in between those of conventional aromatic polyimides and polymers with wholly aliphatic ether diamine links. Through dynamic mechanical analysis and differential scanning calorimetry, it is shown that control of the molar ratios of the aromatic MBDMA and the composition and size of the aliphatic polyetherdiamine can be used to tune the glass transition temperature. The materials were characterized and …

Decorative Articles Based On Polymeric Materials, Yaser M. Asal Mr., M. A. Radwan, Hany A. Elazab Dr, Bassant Hussein, Mohamed A. Sadek

Chemical Engineering

The aim of the research is to create decorative articles based on polymeric materials, study the effects of fillers and the type of moulds that it can cope with the exothermic reaction nature of resin to create a scientific background on the usage of the resins in daily life products. The polymeric materials that will be concentrated on are the unsaturated polyester resins and epoxy resins. The unsaturated polyester is of many types and chemical constituents, the used experimentally is a general-purpose type and the epoxy also have different types and the used is a commercially 3D floor coating type. …

Thermo-Oxidative Degradation Of Hdpe Geomembranes: Effect Of Phenolic Antioxidant And Hindered Amine Light Stabilizer Concentrations, Yasin Kocak

USF Tampa Graduate Theses and Dissertations

High density polyethylene (HDPE) geomembrane is most common geomembrane which is mainly used for civil engineering applications. However, HDPE geomembrane loses its properties under oxidative degradation progress. This study aims to assess geomembranes which have different percentage of phenolic antioxidant and hindered amine light stabilizer (HALS) with under the six months of the thermal-oxidative degradation. The interactions between phenolic antioxidant, HALS and carbon black can affect the mechanical, physical and chemical properties. To monitor these properties, Differential Scanning Calorimetry (DSC), Fourier-transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM/EDX), Melt Index tests, …

Organic Chemistry Ii Lab Manual, Caitlyn Bailey

Senior Honors Theses

This project aims to supply a full lab manual and grading key for Organic Chemistry II, a class often taken by sophomores in Liberty University’s science degree programs. Properly applied laboratory experiments create a beneficial learning environment for science students by using hands-on procedures to transform intangible lecture concepts into concrete demonstrations. Lab work also fosters the development of problem-solving and critical-thinking skills that students need in research and the workplace. Thus, having a comprehensive lab manual is critical to students’ success and understanding in this upper-level class. This project adds to the experiments of Organic Chemistry II lab through …