Polymer Science Commons^™

Assisted Methane Hydrate Formation With The Addition Of Promoters, Chutikan Jaikwang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Natural gas hydrates play an important role in the largest reservoir of hydrocarbons on earth. The gas hydrates have received increasing attention in an excellent way of new technology for gas in large quantity storage and transportation. However, the main challenge to use methane hy¬drates has faced many challenges such as the slow formation rate, low growth rate during hydrate formation, and low conversion ratio of gas to solid hydrates leading to poor storage capacity. In this work, methane hydrate formation and dissociation in the presence of different Cyclopentane (CP), Tetra-n-butyl phosphonium bromide (TBPB) and Tetra-n-butyl ammonium bromide (TBAB) concentrations …

Microbial Conversion Of Cellulose To Sugars By Bacterial Enzyme, Kessara Seneesrisakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work studied the conversion of lignocellulosic materials to sugars, the intermediates for bioethanol production, by a bacterial enzyme. Due to the complex structure of lignocellulose, a cellulase enzyme cannot effectively access and hydrolyse cellulose fibers. Various pretreatment processes of lignocellulose have been studied to enhance enzymatic hydrolysis to date. In this work, corncob was firstly studied for microbial pretreatment using three microorganisms including two bacterial strains of Bacillus subtilis A 002 and Cellulomonas sp. TISTR 784 and a fungal strain of Phanerochaete sordida SK7. The results showed that the microbial pretreatment with P. sordida SK7 was the most effective …

Effects Of Bead Size And Concentration Of Unstable Asphaltenes Obtained From Different Centrifugation Techniques On Asphaltene Deposition In Packed Bed Apparatus, Kimchhay Lao

Chulalongkorn University Theses and Dissertations (Chula ETD)

Asphaltenes are the heaviest and most polar fraction of petroleum crude oil. They are the collection of components that can be soluble in aromatics solvents such as benzene or toluene, but insoluble in normal alkanes, n-pentane, n-hexane, or n- heptane. Asphaltenes are a class of molecules consisted of grouped aromatic rings with alkane chains. Changing pressure, temperature, composition, and shear rate during transportation can cause precipitation and deposition, resulting in reduced reservoir productivity due to restricted flow lines, fouling and blockages in the pore spaces of the reservoir. The goal of this investigation is to assess validity of two aspects …

Adsorptive Bubble Separation For Oil Removal, Paweena Kanokkarn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This present work emphasized on the current knowledge regarding (i) feasibility of multi-stage forth flotation operation for oil removal, and (ii) comprehension of dynamic surface tensions of surfactant solutions in relation to foam characteristics. A multi-stage forth flotation efficiency depends on the enhancement of interfacial adsorption and the number of bubble caps and tray. The operational parameters including foam height, air flow rate and feed flow rate were controlled to obtain the optimum process performance. Under the optimum conditions—a number of trays of 4, a foam height of 60 cm, an air flow rate of 40 L/min, a feed flow …

Investigation Of Asphaltene Aggregation Kinetics In The Presence Of Water-In-Oil Emulsion, Penpitcha Roengsamut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Asphaltene is a component of the petroleum liquid defined operationally. It represents the most refractory (or the heaviest fraction). It is well-known that changes in temperature, pressure, or composition can destabilize asphaltenes and cause aggregation and deposition in porous formations, production lines, and processing facilities (Sheu and Mullins 1995). This leads to the study of the behavior of asphaltene aggregation and parameters that could affect the rate of aggregation which, in this case, is water-in-oil emulsion. In addition, the asphaltene aggregation model derived by Haji-Akbari (2013) is applied as a framework in this study which explains the correlation between the …

Study On Energy Storage Ability Of Zno/Tio2 For Photocatalytic Degradation Of Isopropanol, Ratchawan Jarumanee

Chulalongkorn University Theses and Dissertations (Chula ETD)

The photocatalytic degradation of isopropanol under UV irradiation was studied by using p-n junction of ZnO/TiO2 photocatalysts prepared by sol-gel technique. Their energy storage ability was tested with their photocatalytic activity where there was no UV illumination. That was investigated by illumination the system with UV light for 2 h and off for 2 h until 8 h. The composition and surface structure of the catalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area analysis, and particle size analysis. The change in the isopropanol concentration was observed by using gas chromatography. The result showed that the …

Vegetable Oil Based Microemulsion Biofuels, U-Larak Peson

Chulalongkorn University Theses and Dissertations (Chula ETD)

The growth of energy demand increases dramatically which has resulted in an increase of exhaust emissions to air quality deterioration. Therefore, there are driving forces in the development of renewable energy production technologies. Vegetable oils based reverse micelle microemulsions have been increased in attention for biofuel production. This work aims to formulate microemulsion biofuel containing palm oil/diesel blend as nonpolar phase, and ethanol/butanol, as a polar phase. The nonionic alcohol ethoxylate surfactant with the different numbers of EO groups, EOn (n=1, 3, 5, and 9) were selected as a stabilizing agent. A pseudo-ternary phase diagram was conducted to determine an …

Improvement Of Life Cycle Assessment Software And Its Applications, Yodsathorn Chavewanmas

Chulalongkorn University Theses and Dissertations (Chula ETD)

LCSoft is Life Cycle Assessment (LCA) software which developed for perform LCA together with process design. It is a stand-alone tool with ability to be integrated with other process design tools such as process simulation software (PROII/ASPEN), economic analysis tool (ECON), and sustainable process design tool (SustainPro). In addition, several optional interpretation features are available such as, sensitivity analysis, alternative comparison, and eco-efficiency evaluation. In this research, LCSoft had been improved in performance and application range. The development framework consisted of four tasks. The first task deals with improvement of LCI and LCIA calculation which new pathway for calculation and …

Catalytic Activity Study Of Nixsny Intermetallics, Anchernsiri Noomnual

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cinnamyl alcohol (COL), versatile chemical in fragrance, flavoring, and pharmaceutical industries, can be found in only small amounts in nature. Generally, COL can be synthesized via selective hydrogenation of cinnamaldehyde (CALD), natural oil, at aldehyde functional group under high pressure of hydrogen gas. In this work, NixSny intermetallics were used as catalysts in selective hydrogenation to obtain COL. These catalysts were synthesized via mechanical alloying, economic and environmental method, and characterized by X-ray diffraction (XRD). By using 43, 58, and 75% tin contents with nickel, Ni3Sn, Ni3Sn2, and Ni3Sn4 intermetallics were prepared, respectively. In addition, formic acid was used as …

Electrical Property-Investigation Of Porous Clay Heterostructures Derived From Naturally-Occurring Clay Minerals For Smart Packaging, Kornkamol Srithammaraj

Chulalongkorn University Theses and Dissertations (Chula ETD)

Porous Clay Heterostructure (PCH) is an interesting material to use as entrapping system such as ethylene scavenger, respected to its high surface area with uniform and specific pore size. PCHs have been prepared by the surfactant-directed assembly of mesostructured silica within the two-dimensional galleries of clays. Then, the PCH was synthesized within the galleries of Na-bentonite clay by the polymerization of tetraethoxysilane (TEOS) in the presence of surfactant micelles. In addition, mesoporous clay with organic-inorganic hybrid (HPCH) is modified via co-condensation reaction of TEOS with candidate conductive functional groups (thiol group) and metal loading (silver), designated as MPPCH and Ag-PCH, …

Study The Best Support For Hydrolysis Of Tiger Grass, Kurizara Sayamnikorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bioethanol, one of the outstanding biofuels, is not only a renewable bio-based resource, but also interesting to research for improving better properties of the enzyme needed in the hydrolysis process. The purpose of this work is to study how to reuse the enzyme used in the hydrolysis step for bioethanol production by immobilizing Trichoderma reesei (T.reesei) on various silica supports, namely, SBA-15, TUD-1, and MCM-48. The amount of the adsorbed enzymes was determined by UV-visible spectrophotometry. Among those studied supports, SBA-15 showed 100% enzymatic adsorption on the support owing to its larger pore diameter of 6.14 nm, which is large …

Development Of Pedot-Pss/Zeolite Composite As A Gas Sensor, Pojjawan Chanthaanont

Chulalongkorn University Theses and Dissertations (Chula ETD)

Composites with Poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid), PEDOT-PSS, as the matrix containing zeolites of various Si/Al ratios in the range of 23-280 were fabricated to investigate the effect of Si/Al ratios on electrical conductivity sensitivity responses towards the target gas. The electrical conductivity responses of PEDOT-PSS/Zeolite composites were altered due to the available adsorption sites for gas molecules. The addition of zeolites to the pristine PEDOT-PSS improves the electrical conductivity sensitivity of the composites by enhancing the interaction between PEDOT-PSS and target gas. Composites with PEDOT-PSS matrix containing faujasite zeolites type Y were fabricated to investigate the effects of …

Development Of Water-Based Adhesives For Oriented Polypropylene (Opp) Lamination, Sarocha Ruanpan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Eco-friendly laminating adhesive has been developed for flexible packaging industries due to urgent restriction of volatile organic compounds (VOCs) emissions from anthropogenic sources. The water-based polyurethane laminating adhesive was derived by a condensation polymerization of isophorone diisocyanate, polypropylene glycol and 2,2-bis(hydroxymethyl)propionic acid, while the water-based polyacrylate laminating adhesive was synthesized by an emulsion polymerization of 2-ethylhexyl acrylate, ethylene glycol methyl ether acrylate, styrene, 2-hydroxyethyl methacrylate and acrylic acid. The parameters influencing the adhesive's performance consisted of chemical composition, reinforcing fillers and manufacturing processes. Among those parameters, the fabrication of waterborne core-shell polyacrylate laminating adhesive through a two-stage seeded semi-batch emulsion …

Formulation And Characterization Of Poly(Β-Amino Ester) Networks For Controlled Delivery Of Antioxidants In Pharmaceutical Applications, Vinod Shivaji Patil

Theses and Dissertations--Chemical and Materials Engineering

Oxidative stress, which reflects an imbalance between oxidants and endogenous antioxidants, is known to be a cause as well as an effect of health conditions such as cancer, diabetes, Alzheimer’s disease, Parkinson’s disease and ischemia-reperfusion injury. Antioxidants have shown promising results in vitro in controlling oxidative stress. However, years of in vitro studies have failed to translate into effective clinical interventions for controlling oxidative stress in the disease conditions. This has been due to low bioavailability and lower stability of antioxidants. Poly(antioxidant β-amino esters) (PABAE) are a recently-developed class of biodegradable polymeric hydrogels that have shown promise in their ability …

Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick

Theses and Dissertations--Chemical and Materials Engineering

Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (^PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (^CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries. The …

A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, Yueming Wu

Murray State Theses and Dissertations

ABSTRACT

The polymerization process of, and gas absorption by, imidazolium-containing thiol:ene poly (ionic liquid)s (PILs), prepared from bisallylimidazolium bis(trifluoromethyl sulfonyl)imide [NTf₂^-] and pentaerythritoltetrakis(3 mercaptopropionate), was studied. The thiol:ene PILs examined were recently reported by groups at Murray State University. The advantage of thiol:ene PILs over other reported PILs is that thiol:ene polymers are made rapidly by UV exposure and exhibit high mechanical and thermal stability due to high cross-linking. The properties of interest for the thiol:ene PILs were studied using a quartz crystal microbalance (QCM). QCM techniques are based on the piezoelectric effect, where certain crystals (e.g., …

Engineering Icephobic Coatings: Surface Characterization Of Pt Cured Silicones, Sithara Shylaja Nair

Theses and Dissertations

Ice buildup on structures leads to problems that include reduced performance, structural damage and power outages. It is therefore important to limit the energy required for removal of ice from substrates to minimize buildup. Understanding the mechanism of ice adhesion and its dependence on variables like coating thickness, stiffness, surface free energy and morphology is critical for minimizing adhesion. Despite several developments in “icephobic” coatings, which are those that have low ice adhesion, it is important to understand adhesion on the fundamental level to make way for advanced coatings. To do so, a study has been carried out that explores …

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …

Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe

Dissertations

The body of this work describes a novel approach for the dispersion of multi-walled carbon nanotubes in a high T_g epoxy prepolymer matrix using a twin screw high-shear continuous reactor. The method demonstrated improves on previous dispersion methods in several ways. It offers increased efficiency through excellent heat transfer, while being solvent-less, scale-able, and tailorable to drive dispersion states to judiciously chosen dispersion states. Furthermore, it was shown that dispersion state and agglomerate morphology can be directed, in several ways, through processing conditions and also by controlling the matrix viscosity profile through cure. Broadband dielectric spectroscopy, optical hot-stage microscopy, …

Plasma Processes And Polymers Third Special Issue On Plasma And Cancer, Mounir Laroussi, Annemie Bogaerts, Nazir Barekzi

Electrical & Computer Engineering Faculty Publications

(First paragraph) This issue of Plasma Processes and Polymers is the third in a series on the applications of low temperature plasma (LTP) against cancer, or “plasma oncology.” The papers in this issue are inspired from the talks given at the third International Workshop on Plasma for Cancer Treatment (IWPCT) which took place on April 11–12, 2016 in Washington, DC, USA. IWPCT is an international workshop that was created in 2014 as a venue to share cutting edge plasma oncology research. The first IWPCT was held in Washington DC, under the co-chairmanship of Prof. Mounir Laroussi (Old Dominion University) and …