Chemistry Commons^™

Synthesis Of Cross-Conjugated Dibenzochrysene-Based Photosensitizers For Dye-Sensitized Solar Cells, Bailey Nicole Flamm

Honors Theses

Dye-sensitized solar cells (DSCs) represent a promising alternative method of energy generation. Absorbance of light across the visible spectrum and into the near-infrared (NIR) region is crucial to increasing the power conversion efficiencies (PCEs) of DSC devices. Dye absorbance can be red-shifted by either increasing the conjugation path of the photosensitizer or by increasing the strength of electron donors and acceptors found in molecules. By using a polycyclic aromatic Ï€-bridge in a dye, lower energy wavelengths of light can be absorbed. Dibenzochrysene is a six-ring polycyclic aromatic hydrocarbon (PAH) with substitutable positions that allow for a double-donor, double-acceptor (DD-Ï€-AA) structure, …

Polymer Grafted Nanoparticles For Designed Interfaces In Polymer Nanocomposites, Mohammad Mohammadkhani

Theses and Dissertations

This dissertation presents the design, synthesis, and characterization of polymer nanocomposite interfaces and the property enhancement from this interface design. Through the use of reversible addition fragmentation chain transfer (RAFT) polymerization for the grafting of polymer chains to silica nanoparticles, the surface of silica nanoparticles can be manipulated to tune the properties of nanocomposites by controlling the interface between the particles and the polymer matrix.

In the first part of this work, compatibility of 15 nm silica nanoparticles grafted with different alkyl methacrylates with linear low density polyethylene was investigated. SI-RAFT polymerization of hexyl, lauryl, and stearyl methacrylate on silica …

Disinfection By-Products: Formation In Pool Water And The Role Of Iodinated Medical Imaging Compounds As A Potential Precursor In The Formation Of Iodo-Dbps, Christina Marie Joseph

Theses and Dissertations

Disinfection by-products (DBPs) are the unintended consequence of using chemical disinfectants to kill pathogens in water. 1-11 They are formed from the reaction between disinfectants and natural organic matter (NOM), anthropogenic contaminants, and bromide/iodide present in the raw source water. DBPs are cause for concern because studies have found them to be toxic.11-16 This research focuses on identifying and studying the formation of DBPs. Specifically, the presence of DBPs in chlorinated pool water and tap water from Barcelona, Spain was studied to better understand which DBPs are formed in the pool as compared to those that enter the pool from …

Structural And Functional Studies Of Proteins From The Agricultural Pests Tetranychus Urticae And Aspergillus Fumigatus, Caleb Schlachter

Theses and Dissertations

Agricultural pests are a worldwide problem and cause billions of dollars in crop loss. In the United States alone, an estimated $40 billion USD is lost per year due to insecticide resistance [1]. Studied here are proteins (potentially new pesticide targets) from the agricultural pests Tetranychus urticae and Aspergillus fumigatus. T. urticae, or twospotted spidermite, is a polyphagous pest, and three proteins from this pest, a cyanase, a glutathione S-transferase and an intradiol ring-cleavage dioxygenase are described [2]. Cyanase is involved in the conversion of bicarbonate and cyanate, a toxic self-defense metabolite produced by plants, into ammonia and carbon dioxide. …

Metal-Organic Frameworks: A Versatile Platform For Light Harvesting And Energy Transfer, Derek E. Williams

Theses and Dissertations

The global energy demand is undoubtedly rising at an alarming rate, and as a result, humanity faces the problem of finding alternative energy supplies. Approximately 80 percent of the world’s energy currently comes from fossil fuels, and only a small fraction, 10 percent, from renewable energy sources. The study of energy transfer (ET) processes is a rapidly developing area of interest due to the necessity for more efficient photovoltaic devices, which are crucial to meet the growing energy demand. A promising approach to further advance organic photovoltaics is to precisely arrange many lightharvesting chromophores (e.g., porphyrin derivatives), attainable through a …

Mild Hydrofunctionalizations Of Olefins Using More Cost-Effective Metal Catalysts, Alexander James Villani-Gale

Dissertations

The focus of this dissertation is the study of alkene hydroaylation reactions. In the first chapter, a review of the relevant literature concerning zinc- and iron-catalyzed hydroarylation of unsaturated bonds is presented. In chapter two, the development of a zinc-catalyzed hydroarylation of alkenes is presented, which is quickly followed by a detailed investigation into the probable mechanism. Chapter three discusses the development of an iron/silver-catalyzed arene prenylation reaction, followed by the development of an iron/zinc-catalyzed arene prenylation reaction. The final section of chapter three discusses the adaptation of the iron/zinc-catalyzed arene prenylation into an undergraduate organic teaching laboratory.

Detection Of Unknown Emerging Contaminants In Natural Water Using Tandem Mass Spectrometry, Qian Wang

Dissertations

Recently, a great deal of concern has been given to the quality of drinking water. Lake Michigan is the drinking water source of Chicago area. It is very important that the quality of drinking water meets the standard setup by the EPA. However, there is a group of chemicals that are not being monitored regularly or are unknown to researchers and are the so-called emerging contaminants.

So the objective of this study is to using tandem-mass spectrometry to detect and identify emerging contaminants. Water samples were obtained along a few locations along the Chicago River and Lake Michigan. By using …

Psammaplins Selectively Target Triple-Negative Metastatic Breast Tumor Cells That Are Genetically Programmed To Colonize Specific Organs, Thuy Phuong Le

Honors Theses

Five bromotyrosine-derived marine sponge metabolites, four psammaplins (1 — 4) and the psammaplin dimer, bisaprasin (5) were isolated from a lipid extract sample of the marine sponge Dendrilla lacunosa. Â Psammaplins act as histone deacetylase (HDAC) inhibitors that alter cellular gene expression. Â The D. lacunosa psammaplins activated the oxygen regulated transcription factor HIF-1 (hypoxia-inducible factor-1) in T47D human breast tumor cells and displayed cell line specific effects against aggressive organotropic metastatic cell lines that were derived from triple-negative MDA-MB-231 human breast tumor cells.

The Potential Of Atmospheric Air Cold Plasma For Control Of Bacterial Contaminants Relevant To Cereal Grain Production, Agata Los, Dana Ziuzina, Daniela Boehm, Patrick J. Cullen, Paula Bourke

Articles

The aim of this work was to investigate the efficacy of dielectric barrier discharge atmospheric cold plasma (DBD ACP) against bacteria associated with grains quality and safety. ACP inactivation efficacy was tested against biofilms formed by different strains of E. coli, Bacillus and Lactobacillus in grain model media and against B. atrophaeus endospores either in grain media or attached on abiotic surfaces. Effects were dependent on bacterial strain, media composition and mode of ACP exposure. ACP treatment for 5min reduced E. coli spp., B. subtilis and Lactobacillus spp. biofilms by >3 log10, whereas insignificant reductions were achieved for B. atrophaeus. …

Impact Of Atmospheric Pressure Nonequilibrium Plasma Discharge On Polymer Surface Metrology, Laurence Scally, James Lalor, Patrick J. Cullen, Vladimir Milosavljevic

Articles

Due to the attraction of plasma technologies as a clean and efficient means of surface modification, significant research has gone into the physical and chemical aspects of polymer functionalization. In this study, it was shown that the use of an atmospheric plasma jet can efficiently modify the surface of polyethylene terephthalate samples and change their hydrophobic properties to more hydrophilic characteristics. The dependence on the changes with respect to time, distance, and atomic oxygen (O I) intensity were considered as factors. It was found that with closer proximity to the plasma source (without causing thermal degradation) and with increasing levels …

Evaluation Of Chemical Immersion Treatments To Reduce Microbial Populations In Fresh Beef, Ahmed Kassem, Joseph Meade, James Gibbons, Kevina Mcgill, Ciara Walsh, James Lyng, Paul Whyte

Articles

The aim of the current study was to assess the ability of a number of chemicals (acetic Acid (AA), citric acid (CA) lactic acid (LA), sodium decanoate (SD) and trisodium phosphate (TSP)) to reduce microbial populations (total viable count, Campylobacter jejuni, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes) on raw beef using an immersion system. The following concentrations of each chemical were used: 3 & 5% for AA, CA, LA, SD and 10 & 12% for TSP. Possible synergistic effects of using combinations of two chemicals sequentially (LA +CA and LA +AA) were also investigated. L*, a* and b* values …

Mechanistic Studies Of Nucleic Acid Chaperone Activities Of Retroviral Nucleocapsid Protein, Lichao Sun

Theses and Dissertations

In this dissertation, I have used single molecule Fluorescence Resonance Energy Transfer (sm-FRET), as a nanoscale spectroscopic ruler to gain quantitative, molecular-level understanding about the kinetics and mechanism of NC-chaperoned TAR sequence rearrangements. Firstly, I have resolved the complex kinetics and underlying reaction pathways of TAR sequence annealing in the presence of HIV-1 NC over a broad NC concentration by performing the time-resolved sm-FRET measurements in a unique aggregation-free environment. I have further gained the insights that the NC-induced secondary structural changed of TAR hairpins modulate the annealing pathways and consequently affect the overall kinetics of the TAR sequence annealing. …

Assessing Aberrant Glycosylation With Synthetic Lectins To Detect And Stage Prostate Cancer, Anna Veldkamp

Theses and Dissertations

Aberrant glycosylation takes place during the onset of cancer and throughout the progression of the disease allowing certain glycans to serve as biomarkers1. Boronic acid functionalized synthetic lectins (SLs) have been shown to bind selectively and crossreactively to certain glycoproteins through covalent yet reversible interactions between the boronic acids and 1,2- or 1,3-diols found on saccharides2. This project focuses on 1) data acquisition optimization of an existing SL array; 2) the identification, isolation, and characterization of new SLs that interact with proteins and glycoproteins targeting the prostate and prostate cancer; and 3) the utilization of new SLs in cross-reactive sensor …

Characterization Of The Suf Fe-S Pathway In Escherichia Coli, Naimah Bolaji

Theses and Dissertations

Iron is an essential transition metal required by almost all organisms for use as a cofactor in many metabolic processes such as respiration and photosynthesis. Iron can be combined with elemental sulfur to form an iron-sulfur (Fe-S) cluster. In bacterial pathogens, Fe-S cluster cofactors carry out critical functions and the Fe-S cluster biogenesis pathway is essential for their survival. In E. coli, the Suf pathway assembles Fe-S clusters under conditions of iron starvation and oxidative stress. While some mechanistic details of the Fe-S cluster biogenesis have been well-characterized, the process of in vivo iron donation remains unclear. Iron storage proteins …

Investigation Of Iron(Ii) Autoxidation Rate And Iron Mediated Geochemical Production Of Reactive Oxygen Species At Oxic-Anoxic Interfaces, Dewamunnage Muditha Chathurangani Dias

Theses and Dissertations

Biogeochemical cycles in ecosystems regulate the flow of energy between reduced species (typically carbon compounds) and a variety of oxidants via both biotic and abiotic reactions. A key class of chemical compounds that can link these cycles through abiotic pathways are Reactive Oxygen Species (ROS). The production of ROS via photochemical pathways is well known. More recently, the non-photochemical production of ROS via the one electron oxidation of ferrous iron (Fe(II)) by dioxygen (O2) has been detected in a range of environments. The oxidation of Fe(II) initiates a pathway that generates an array of ROS as Fe is cycled between …

Chemical Sensing In Harsh Environments By Multivariate Optical Computing, Christopher Michael Jones

Theses and Dissertations

Multivariate optical computing (MOC) is a compressive sensing technique for which an analyte concentration is detected in an interfering mixture by direct detector output. The detector measures the dot product of a linear regression vector with a sample spectrum, as an analog optical computation. The computation is accomplished with the multivariate optical element (MOE), to which the optical regression vector is encoded as a transmission pattern. As a spectrum of light emanates from a sample and passes through the MOE, the dot product naturally occurs when light strikes the detector. The MOC platform allows a simple, robust, and direct measurement …

Sustainable Polymeric Materials Derived From Plant Oils: From Synthesis To Applications, Xinzhou Zhang

Theses and Dissertations

In this thesis, monomers and polymers derived from high oleic soybean oil are investigated. The properties of these monomers and polymeric materials are characterized and discussed. Chapter 1 describes an overall background of bio-based resources, monomers, polymers, and their potential impact on society. The overall objective of my research is described. Chapter 2 outlines a new large-scale preparation of a soybean based monomer and the use of this monomer in thermoplastic elastomers. The synthetic procedures and characterizations of the monomers and polymers are discussed. In Chapter 3, potential applications of soybean oil monomers in both supramolecular polymers and poly(phosphoester)s are …

Targeting Aberrant Glycosylation In Colon And Prostate Cancer With An Improved Synthetic Lectin Array, Tanya Hundal

Theses and Dissertations

Cancers of the colon and prostate, though treatable, necessitate early detection to improve patient outcomes. Current diagnostics, (visual methods or biopsies) besides being invasive, are subjective towards interpretation, thus decreasing accuracy. Alternatively, blood-based tests involving measuring of specific biomarkers (like CEA and PSA for colon and prostate cancers, respectively) are associated with high false-positive rates and are more useful for monitoring post-treatment patient health, thus driving efforts to identify better screening and diagnostic techniques.

Abnormal glycosylation of integral membrane and secreted glycoproteins is known to take place at the onset of many diseases, including cancer, and presents as the over, …

พอลิแล็กทิกแอซิด/พอลิไวนิลแอลกอฮอล์/แกรฟีนนาโนคอมพอสิต, จาฬุพักต์ รัตนคช

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อพัฒนาวิธีการเตรียมพอลิแล็กทิกแอซิด/พอลิไวนิลแอลกอฮอล์/แกรฟีนนาโนคอมพอสิต รวมถึงศึกษาอิทธิพลของการเติมอนุภาคแกรฟีนต่อสัณฐานวิทยา สมบัติเชิงกล สมบัติทางความร้อน และสมบัติการนำไฟฟ้าของวัสดุนาโนคอมพอสิตที่เตรียมได้ โดยเริ่มด้วยการสังเคราะห์แกรฟีนจากแกรไฟต์ด้วยวิธีของฮัมเมอร์ และใช้กรดแอลแอสคอร์บิกเป็นตัวรีดิวซ์ พิสูจน์เอกลักษณ์ของอนุภาคแกรฟีนที่เตรียมได้ด้วยเทคนิคอินฟราเรดสเปกโทรสโกปีและเทคนิคเอกซเรย์ดิฟแฟรกชัน จากนั้นเตรียมของผสมระหว่างพอลิไวนิลแอลกอฮอล์กับแกรฟีนที่ปริมาณต่าง ๆ ด้วยวิธีแช่เยือกแข็ง แล้วนำไปผสมกับพอลิแล็กทิกแอซิดด้วยเครื่องอัดรีดสกรูคู่และขึ้นรูปเป็นชิ้นงานด้วยกระบวนการอัดแบบ ศึกษาสัณฐานวิทยาเพื่อวิเคราะห์อันตรกิริยาของผสมระหว่างพอลิไวนิลแอลกอฮอล์กับแกรฟีนด้วยกล้องจุลทรรศน์แบบคอนโฟคอล และวิเคราะห์ภาคตัดขวางของชิ้นงานคอมพอสิตด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด ผลการทดสอบสมบัติเชิงกล สมบัติทางความร้อน และสมบัติการนำไฟฟ้าของวัสดุนาโนคอมพอสิตที่เตรียมได้ พบว่าปริมาณผลึกลดลงเมื่อปริมาณแกรฟีนเพิ่มขึ้น แต่ไม่ส่งผลต่ออุณหภูมิกลาสทรานสิชัน อุณหภูมิหลอมเหลวผลึก และอุณหภูมิการเกิดผลึก อีกทั้งการเติมแกรฟีนที่มีการใช้พอลิไวนิลแอลกอฮอล์เป็นตัวพาลงในพอลิเมอร์เมทริกซ์ ทำให้ความทนแรงดึง และความยืดสูงสุด ณ จุดขาด มีแนวโน้มลดลงด้วย อย่างไรก็ดีการเติมแกรฟีนในปริมาณน้อย ๆ สามารถช่วยเพิ่มความทนแรงดึงได้เมื่อเปรียบเทียบกับงานวิจัยก่อนหน้าที่ไม่มีการเติมตัวพาหรือตัวช่วยเพิ่มการกระจายตัว นอกจากนี้พบว่าปริมาณแกรฟีนที่เพิ่มขึ้น ทำให้ค่าการนำไฟฟ้าของคอมพอสิตเมื่อเทียบกับพอลิแล็กทิกแอซิดบริสุทธิ์เพิ่มขึ้น คอมพอสิตที่พัฒนาขึ้นสามารถนำไปประยุกต์ในงานที่ต้องการสมบัติการต้านทานไฟฟ้าสถิตย์ได้

3d Printing Of Graphene/Thermoplastic Elastomer Composites, Warrayut Kanabenja

Chulalongkorn University Theses and Dissertations (Chula ETD)

Graphene based thermoplastic polyurethane composites filaments was prepared by melt blending process prior to fabricate with 3D printing technique. The effects of different graphene loading (0.05 wt% - 0.20 wt%) in TPU matrix on the properties of composites were studied. Initially, graphite was successfully oxidized to graphite oxide following Hummer’s method and the reduction of graphene oxide to graphene by L-ascorbic acid was also achieved as being confirmed by the FTIR and XRD results. TPU and TPU/graphene nanocomposites were investigated for their thermal, mechanical, physical and electrical properties. Thermal stability of TPU/graphene composites was improved against neat TPU. The first …

Catalytic Hydrogenation Of Carbon Dioxide For Hydrocarbon Synthesis, Nuttakorn Boreriboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Catalytic hydrogenation can turn CO2 into hydrocarbon fuel. The development of the catalysts for CO2 hydrogenation has become important since the catalysts are critical for selective production of more higher hydrocarbons for practical application. In this work, the titania supported monometallic and bimetallic Fe-M (M = Co and Cu) catalysts were synthesized and tested for CO2 hydrogenation at 573 K and 1.1 MPa. Among the monometallic catalysts (Fe, Co and Cu/TiO2), only Fe/TiO2 catalyst exhibited some selectivity to higher hydrocarbons, while Co/TiO2 and Cu/TiO2 catalysts were highly selective only to CH4 and CO, respectively. The addition of a small amount …

Hydrogen Rich Gas Production From Pyrolysis-Gasification Of Biomass With Combined Catalyst And Sorbent, Teerayut Bunma

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, the hydrogen production during biomass steam pyrolysis-gasification with a combined catalysts and sorbent (catalyst/sorbents) was studied in a drop tube two-stages fixed bed reactor. The catalyst/sorbents were prepared by an excess-solution impregnation method. A nickel oxide (NiO)/magnesium oxide (MgO)/calcium oxide(CaO) catalyst/sorbents containing 10 wt. % NiO, 5 wt. % MgO and 5 wt. % CaO on gamma alumina (γ-Al2O3) showed the best activity in sorption enhanced hydrogen production (SEHP) for the pyrolysis-gasification of sugarcane leaves. Besides, the highest H2 concentration and the lowest CO2 concentration were attained using the Mg5Ni10Ca5 catalyst/sorbents. Because Mg5Ni10Ca5 catalyst/sorbents provided the dominant …

Synthesis Of Bi- And Trifunctional Mesoporous Silica-Based Catalyst And Application In One-Pot Cascade Reactions, Apichat Klayanon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work reports the synthesis and full characterization of bifunctional mesoporous silica supported acid (-SO3H)-base (-NH2) catalysts and trifunctional mesoporous silica supported acid-base-metal catalysts as well as their applications. A series of bifunctional catalysts were synthesized with different site separations, acid loadings, base loadings and types of aminosilane, namely N2SA2, SA0.5N0.5, SA0.5N2, SA1N2, SA2N2, SA0.5N4, SA0.5NN4 and SA0.5NNN4, via a co-condensation and post-synthetic grafting methods and were characterized by XRD, FT-IR, N2 adsorption-desorption, SEM, TEM, TGA and XPS techniques. The well-ordered hexagonal mesoporous structure was preserved throughout the synthesis where the synthesized materials exhibited small kidney-bean-shaped rod and highly ordered …

Nanomaterial Sensors For Selective Detection Of Biothiol Compounds, Chiraporn Chaicham

Chulalongkorn University Theses and Dissertations (Chula ETD)

Novel nanomaterial sensors have been designed two different strategies of sensing approach. The first sensing system, the aggregation nanomicelles (TSC and TSD) were synthesized for GSH sensing based on disulfide-cleavaged trigger in the micelle. The result showed a large quenching fluorescent intensity around 587 nm and 528 nm corresponding to TSC and TSD, respectively, upon the addition of GSH in 2.5% DMSO/PBS at pH 6. Additionally, the benefit of TSD is utility for the distance-based fluorescence detection of 3D paper analytical device (3D-µPAD) for the detection of GSH. Apart from GQDs sensors base, we demonstrated the utility and board applicability …

Photocatalytic Conversion Of Glycerol To Dihydroxyacetone, Trin Jedsukontorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work was carried out to convert glycerol to value-added compounds in liquid phase over TiO₂-based photocatalyst. The investigated parameters were catalyst dosage (1-3 g/L), H₂O₂ concentration (0.3-1.5 mol/L), UV light intensity (1.1-4.7 mW/cm²), reaction time (4-8 h) and electron acceptor types (O₂ and H₂O₂). It was found that TiO₂ in anatase phase can achieved the glycerol conversion of around 71.42% at catalyst dosage of 3 g/L, H₂O₂ concentration of 1.5 mol/L, UV light intensity 4.7 mW/cm² and reaction time 8 h. The addition of monometallic (bismuth, platinum, palladium, and gold) and bimetallic (gold-bismuth, gold-platinum, and gold-palladium) on TiO₂ can …

Synthesis And Optical Properties Of Pyrrolidinyl Peptide Nucleic Acid Carrying Fluorescence Nucleobases, Duangrat Nim-Anussornkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Pyrrolidinyl peptide nucleic acid bearing D-prolyl-2-aminocyclopentanecarboxylic acid backbone (acpcPNA) is a nucleic acid mimic that shows superior binding affinity, stability and specificity to complementary DNA than the original PNA. This research focuses on the development of hybridization responsive fluorescence acpcPNA probes bearing fluorescent nucleobases that exhibit fluorescence increase upon hybridization to a specific nucleobase in the DNA target. The acpcPNA carrying the fluorescent nucleobases were synthesized via two different approaches, namely 1) pre-synthesized fluorescence PNA monomer as a building block that was subsequently incorporated into the PNA by solid phase synthesis and 2) post-synthetic modification of acpcPNA carrying a reactive …

Application Of Headspace-Gas Chromatography-Mass Spectrometry For Characterization Of Volatile Compounds In Chicken Eggs, Hanan Jehma

Chulalongkorn University Theses and Dissertations (Chula ETD)

Volatile compounds in chicken eggs under the cold chain system and non-cold chain system were characterized by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with chemometrics. According to a central composite design, the following optimum HS-SPME extraction conditions were obtained: extraction temperature of 65 oC, extraction time of 45 min and the amount of NaCl of 0.4 g. In comparison of their mass spectrum and linear retention index from HS-SPME-GC-MS analysis, major volatile compounds found in egg samples included toluene, hexanal, nonanal and other minor volatile compounds were heptanal, octanal, decanal, benzaldehyde, 1-octen-3-ol and 2-ethyl-1-hexanol, with the types and amounts …

Synthesis Of Cationic Cdse/Zns Quantum Dots And Applications In Dna Detection, Jamornpan Yangcharoenyuenyong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Semiconductor nanoparticles or quantum dots (QDs), especially CdSe/ZnS QDs, are of great interest in bioapplications due to their unique size-dependent optical properties and photo-stability. One of the plausible applications of QDs is DNA detection using QDs as a novel fluorescence tool for sensing of DNA using the electrostatic interaction between negative charge of DNA and positive charge on QDs surface. In this work, CdSe/ZnS QDs were synthesized using a hot-solution decomposition process resulting in hydrophobic CdSe/ZnS QDs. To obtain water-soluble and cationic QDs, the surface of QDs were modified with poly(ethylene)imine (PEI) via micelle formation. Because of hydrophilicity of PEI …

Enantiomeric Separation Of Alcohols By Gas Chromatography And Qspr Study To Predict Enantiomeric Separation, Kittiyakorn Toboonpha

Chulalongkorn University Theses and Dissertations (Chula ETD)

Enantiomeric separation of 55 alcohols (13 aliphatic alcohols and 42 alcohols of aromatic structure) was studied by gas chromatography using octakis(2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-γ-CD (or GSiAc) as a chiral stationary phase. For separation under temperature program, 44 alcohols could be enantioseparated. The only aliphatic alcohol that could be completely separated into their enantiomers was 2-hexanol. Twenty-five alcohols, based on 1-phenylethanol, were selected to study under isothermal conditions. For halogen-substituted 1-phenylethanols, temperature strongly affected enantioselectivities of para-substituted alcohols. However, temperature affected enantioselectivities of methyl- or trifluoromethyl-substituted alcohols at ortho-position more than other positions. For para-substituted alcohols, enantioseparations could be improved with the substituent in …

Selective Esterification Of Glycerol With Oleic Acid Using Tungstophosphoric Acid Supported On Functionalized Mesoporous Silica, Kullatida Ratchadapiban

Chulalongkorn University Theses and Dissertations (Chula ETD)

A series of protonated amine-functionalized SBA-15 materials was successfully prepared. Each sample of mesoporous SBA-15 was first functionalized with each of the three types of amino-organosilanes: APTES (N), AAPTMS (NN), and DETTMS (NNN). Each of the resulting materials was then protonated with Keggin-type tungstophosphoric acid (HPW) at two different concentrations: 20 wt.% (H20) and 40 wt.% (H40). The six types of materials obtained were labelled as S-N1-H20, S-N1-H40, S-NN1-H20, S-NN1-H40, S-NNN1-H20, and S-NNN1-H40. The materials were fully characterized by XRD, N2 adsorption-desorption, FT-IR, SEM/EDX, TEM, and elemental analysis. The characterization results show that the synthesized materials exhibited highly ordered hexagonal …