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Articles 2221 - 2250 of 2807
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Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna
Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigated the effect of water content in waste cooking oil (WCO) on the performance of a reactive distillation column for biodiesel production via ester-transesterification. A mixture of triolein and oleic acid was used as a WCO model compound. Amberlyst-15 was used to catalyze esterification while CaO was used for transesterification. From Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model taking into account water absorption for esterification of oleic acid (FFA), biodiesel yield was decreased with increasing of water content in WCO feedstocks. On the other hand, the initial rate of transesterification was increased with increase of amount of water in WCO feedstocks …
Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot
Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study aims to synthesize the production of biodiesel (oleic acid methyl ester) by esterification in the presence of sulfonated hydrothermal carbon based catalyst under microwave irradiation. The catalyst was prepared by hydrothermal carbonization, followed by sulfonation presenting sulfonic acid group as an active site. The catalyst characterization results confirmed good microwave-absorptivity of the catalyst which can be heated directly and accelerate the reaction immediately at the surface of the catalyst. Esterification of oleic acid (OA) with methanol experiments were optimized by using response surface methodology based on central composite design. Three variables: molar ratio of methanol to OA (2.5:1-7.5:1), …
Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol
Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol
Chulalongkorn University Theses and Dissertations (Chula ETD)
The aim of this thesis is to develop a catalyst for the cathode of a zinc-air battery and to investigate the effects of reduced graphene oxide decorated with silver nanoparticles on the cathode in the zinc-air battery. First, reduced graphene oxide (AgNPs/rGO) was synthesized using glucose reduction at 60 degrees Celsius. Next, the structure and morphology of AgNPs/rGO were checked using X-ray diffraction (XRD). Then, transmission electron microscopy (TEM) analyzes were carried out. The amount of silver (Ag) decorate in graphene oxide was confirmed by EDX. Next, the synthesized catalysts at 3 concentration, using a rotating disk electrode (RDE), led …
Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk
Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, most of chicken products are from a closed house system. Climate inside such chicken house can significantly affect chicken welfare and its productivity. Moreover, Thailand is in a tropical region where thermal stress is easily occurred. Suitable operating condition and chicken house design can help improve interior climate which can be evaluated by computational fluid dynamics (CFD) modeling technique. In this study, realizable k-ε model, energy conservation and species transport equations were applied to simulate the air velocity, temperature and relative humidity, respectively, inside the chicken house. The model was validated with measured air velocity, temperature and relative humidity …
Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad
Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research concentrates on the design and performance analysis of a solid oxide fuel cell (SOFC) and a molten carbonate fuel cell (MCFC) integrated system with using methane as fuel. Because SOFCs cannot completely use their fuel, there is remaining fuel leaving the system. In addition, the exhaust gas from an SOFC can be directly fed into an MCFC. The integrated fuel cell system shows an electrical efficiency of 55.22%, which is higher than a single fuel cell system. Fuel utilization of both fuel cells, SOFC temperature dramatically affect the performance of the integrated system. Four configurations were next proposed …
Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook
Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research studied the synthesis and application of black titanium dioxide in the photocatalytic degradation of methyl orange (MO). First, titanium dioxide was prepared via a sol-gel method. Then sodium borohydride was used as the reducing agent in order to synthesize black titanium dioxide. Thus, a 2x2x3 factorial experimental design was employed to assess the significance of the following three factors: (A) calcination temperature (400 and 500 °C); (B) calcination time (5 and 10 h); and (C) the molar ratio of NaBH4 to TiO2 used (0:1, 0.5:1, and 1:1). The removal of MO under UV and visible light were the …
Carbon Dioxide Capture On Nitrogen-Doped Carbon Nanoparticle Derived From Aromatic Compounds Via Solution Plasma And Nitridation, Phuwadej Pornaroontham
Carbon Dioxide Capture On Nitrogen-Doped Carbon Nanoparticle Derived From Aromatic Compounds Via Solution Plasma And Nitridation, Phuwadej Pornaroontham
Chulalongkorn University Theses and Dissertations (Chula ETD)
The carbon dioxide (CO2) adsorption on nanocarbon (C), oxygen-doped nanocarbon synthesized from benzene and a mixture of benzene and metal working fluid (MWF), respectively, via solution plasma process (SPP) have been revealed in this study. Firstly, they showed low CO2 adsorption capacity at 25 °C. However, their capacities were enhanced by nitridation under ammonia atmosphere at high temperature. The maximum CO2 adsorption capacity of 1.63 mmol g-1 was achieved on nitrogen-oxygen-codoped nanocarbon obtained from SPP discharging a mixture containing 15 vol% MWF nitrided at 800 °C (noC15(800)). The characterizations revealed that the micropososity and nitrogen functionality on the adsorbent are …
Computational Fluid Dynamics Of Fluid Transport And Deposition Of Particles Under Unsteady Flow In Human Fluid System, Ratchanon Piemjaiswang
Computational Fluid Dynamics Of Fluid Transport And Deposition Of Particles Under Unsteady Flow In Human Fluid System, Ratchanon Piemjaiswang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Computational fluid dynamics has been widely used to investigate flow phenomena in many different applications. This study focuses on the development of computational fluid dynamic model in biomedical applications, including the flow within human respiratory system and the flow within human circulating system. For the model of respiratory system, electrostatic charge model was coupled, and the effect of breathing frequency was investigated. The accomplishment of the study will gain better understanding of the hydrodynamics when applying the electrostatic field, and will use to identify the potential aerosol deposition location. The aerosol properties and morphologies were also considered their effect on …
Development Of Optical Sensor For Detection Of Chloride Ions And Electrochemical Sensor For Detection Of Clinical Indicators, Abdulhadee Yakoh
Development Of Optical Sensor For Detection Of Chloride Ions And Electrochemical Sensor For Detection Of Clinical Indicators, Abdulhadee Yakoh
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation concentrated on the development of nanomaterials-based miniaturized platforms for the detection of some important compounds/indicators from environmental, pharmaceutical, and clinical application. This dissertation can be classified into two main parts: (1) development of nanomaterials-based miniaturized platforms for optical sensing application, and (2) development of nanomaterials-based miniaturized platforms for electrochemical sensing applications. In the first part, two sub-sections were discussed. For the first sub-section, the paper-based colorimetric sensor for chloride ion determination using silver nanoprisms was developed. Using a smartphone as an optical readout, the color change from the oxidative etching of the silver nanoprisms to the silver nanospheres …
Development Of Sr₂Fetio[₆-Delta] Electrode For Solid Oxide Fuel Cell, Ausa Potong
Development Of Sr₂Fetio[₆-Delta] Electrode For Solid Oxide Fuel Cell, Ausa Potong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Sr₂FeTi₁-x(Nb,V)xO₆ (x=0.05-0.50) double perovskites have been synthesized by the substitution of Nb and V on Ti sites of Sr₂FeTiO₆ (SFT) and tested as electrode for intermediate temperature solid oxide fuel cell (IT-SOFC). The XRD analyses indicated Sr₂FeTi₀.₉₅Nb₀.₀₅O₆ and Sr₂FeTi₀.₉₅V₀.₀₅O₆ were pure and the impurities, Sr(FeNb) ₀.₅O₃ and Sr3(VO4) ₂, were found with the increasing of Nb and V contents in SFT. By small addition of Nb and V in SFT, the electrical conductivity and electrochemical property of SFT was improved. Among the various oxide examined, Sr₂FeTi₀.₉₅Nb₀.₀₅O₆ and Sr₂FeTi₀.₉₅V₀.₀₅O₆ showed the highest electrical conductivity of 2.44 and 3.93 S cm⁻¹, respectively, …
Carbon Sorbent Reinforced Hollow Fiber Membrane Microextraction For Determination Of Trace Polar Organic Compounds, Chanatda Worawit
Carbon Sorbent Reinforced Hollow Fiber Membrane Microextraction For Determination Of Trace Polar Organic Compounds, Chanatda Worawit
Chulalongkorn University Theses and Dissertations (Chula ETD)
This work presents a proof of concept that hollow fiber liquid phase microextraction reinforced with carbon nanomaterials would improve the extraction efficiency of small and relatively polar organic compounds. Several types of carbon sorbents such as graphite, graphene, carbon nanofiber were studied. In research I, the hollow fiber membrane reinforced with graphite was developed for liquid phase microextraction of trihalomethanes in water samples. Parameters affecting extraction efficiency including organic solvent as supported liquid membrane, amount of loaded graphite and extraction time were investigated and optimized. The working range of 0.2-120 µg L-1 was obtained in 10 min extraction with good …
Development Of Electrochemical And Colorimetric Methods Using Inorganic Nanomaterials For Detection Of Biological And Environmental Compounds, Chanika Pinyorospathum
Development Of Electrochemical And Colorimetric Methods Using Inorganic Nanomaterials For Detection Of Biological And Environmental Compounds, Chanika Pinyorospathum
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research comprised of 2 parts including (1) lab-on-paper coupled with electrochemical method for C-reactive protein and colorimetric detection for phosphate ions and (2) the development of chromatographic techniques and its applications. In each part, it can be classified in 2 works. The first work of lab-on-paper is the electrochemical sensor that was fabricated from phosphorylcholine assembled electrodeposited gold nanoparticles onto screen-printed carbon electrode for C-reactive protein detection. Current of ferrocyanide decrease linearly when increase C-reactive protein concentration from 5.0 – 5000 µg L⁻¹. The calculated detection limit equals 1.60 µg L⁻¹. The final part of lab-on-paper is the colorimetry …
Study Of Substitution Reaction On Ring A Of Estradiol, Chanoknun Boonyaratsewee
Study Of Substitution Reaction On Ring A Of Estradiol, Chanoknun Boonyaratsewee
Chulalongkorn University Theses and Dissertations (Chula ETD)
Estradiol-conjugated anticancer drugs are the effective strategy that could specifically combat breast cancer cells, while minimizing the toxicity of the drug toward normal cells. Estradiol has been previously conjugated with drugs mostly at rings B, C and D. Functionalizations at ring A of estradiol introduce new types of conjugated drugs that could improve both the selectivity and efficiency in binding with estrogen receptor (ER). Using 4-cresol as the model, the nitration at meta-position was achieved, although with unsatisfied result of only 6% overall yield of the product. The practical results derived from diazo coupling on ortho-position of 4-cresol, which led …
Molecularly Imprinted Polymer Modified Optical Fiber Sensor Based On Surface Plasmon Resonance Spectroscopy For Determination Of Atrazine, Chidchanok Tabtimhin
Molecularly Imprinted Polymer Modified Optical Fiber Sensor Based On Surface Plasmon Resonance Spectroscopy For Determination Of Atrazine, Chidchanok Tabtimhin
Chulalongkorn University Theses and Dissertations (Chula ETD)
A sensitive sensor device based on surface plasmon resonance (SPR) spectroscopy was developed on an optical fiber and made to be selective to atrazine by molecularly imprinted polymer. The SPR probe was fabricated by deposition of gold nanoparticles on the uncladed surface of an optical fiber by self-assembly method. The size and distribution of gold nanoparticle was optimized by varying the soaking time of the optical fiber. The surface was further modified for selective sensing of atrazine with the molecularly imprinted polymer (MIP). The MIP was synthesized via 2 methods, the first was thermal polymerization method, the MIP was then …
Enzymatic Reaction Based Biosensor For Specific Detection Of Organophosphate Pesticides, Chonticha Sahub
Enzymatic Reaction Based Biosensor For Specific Detection Of Organophosphate Pesticides, Chonticha Sahub
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to design and develop two-biosensor platforms based on graphene quantum dots (GQDs) via enzymatic reaction for determining organophosphate pesticides (OPs). A first platform consisting of GQDs and active enzyme, GQDs/Enz platform, is simply fabricated in aqueous solution. Ongoing development of GQDs/Enz platform for effective OPs sensing by hybrid hydrogel (GQDs/Enz/Gels) was of great interest to improve the sensitivity and enzyme stability under the benefit of easy to be used for sensing approach. The GQDs/Enz and GQDs/Enz/Gels were constructed and characterized by general methods such as FT-IR, SEM and TEM. Based on the concept, H2O2 generated in situ …
Adsorption Of Tetrachloroaluminate Ion On Graphene Quantum Dots, Fadjar Mulya
Adsorption Of Tetrachloroaluminate Ion On Graphene Quantum Dots, Fadjar Mulya
Chulalongkorn University Theses and Dissertations (Chula ETD)
The important thing in the mechanism of aluminium ion battery is the fast adsorption of tetrachloroaluminate [AlCl4]- on intercalation sites of bulk graphite which can increase the efficiency and lifetime of the battery. In this study, we modeled graphene quantum dots (GQDs) as cathode material. For the adsorption of [AlCl4]-, coronene (C24H12) and circumcoronene (C54H18) were used as the model of GQDs with three types of adsorption sites and standing positions. The charge of GQDs was modified to be 0 and +1 to address discharging and charging conditions. The distance between chlorine atom and carbon atom of GQDs was found …
Green Synthesis Of Guanidines Directly From Thiourea, Jakkrit Srisa
Green Synthesis Of Guanidines Directly From Thiourea, Jakkrit Srisa
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, one-pot synthesis of guanidines directly from isothiocyanates using DIB (diacetoxyiodobenzene) as a desulfurizing agent under a micellar condition in water was developed. The optimization study revealed that the use of 1wt%TPGS-750-M as a surfactant with NaOH as a base at room temperature can convert aromatic isothiocyanates and varieties of amines into the corresponding guanidines in good to excellent yields (69 - 95%). This green synthetic process in water can be applied to prepare guanidine at gram-scale quantity. The aqueous micellar medium was also reusable to give relatively the similar reaction yields for at least three cycles. The …
Application Of Capillary Electrophoresis For Determination Of Glycosaminoglycans In Biological And Cosmetic Samples, Kanokporn Chindaphan
Application Of Capillary Electrophoresis For Determination Of Glycosaminoglycans In Biological And Cosmetic Samples, Kanokporn Chindaphan
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research, on-line preconcentration and determination of glycosaminoglycans (GAGs), especially chondroitin sulfate (CS), dermatan sulfate (DS) and hyaluronic acid (HA) using capillary electrophoresis (CE) was developed. Large-volume sample stacking using an electroosmotic flow (EOF) pump (LVSEP) technique was employed for on-line preconcentration and improvement of the detection sensitivity in CE method. Central composite design (CCD) was used to simultaneously optimize all parameters for CE separation. The optimized CE conditions were background electrolyte consisting of 200 mM sodium dihydrogen phosphate, 200 mM buthylamine and 0.5% w/v polyethylene glycol at pH 4.0 and separation voltage of -16 kV. Limit of detections …
Electrochemical Detection Of Herbicides And Antioxidants Using Nanomaterial-Modified Electrode, Kanokwan Charoenkitamorn
Electrochemical Detection Of Herbicides And Antioxidants Using Nanomaterial-Modified Electrode, Kanokwan Charoenkitamorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation focused on the development of a novel nanomaterial-based electrochemical sensors for pharmaceutical and environmental applications. The research is divided into two parts. In the first part, a low-cost and disposable sensor for the simultaneous determination of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA) using manganese (IV) oxide-modified screen-printed graphene (MnO2/SPGE) electrode was developed. The incorporated MnO2 in the SPGE can greatly enhance the detection performance towards the oxidation of CoQ10 and ALA. The cyclic voltammetry (CV) and square-wave anodic stripping voltammetry (SWASV) were employed to investigate the electrochemical behavior of the developed sensor and also to perform the …
Dft And Dftb Investigations On Α–Mangostin Dye Adsorbed On Titanium Dioxide Electrode In Dsscs Application, Kanthira Kaewsud
Dft And Dftb Investigations On Α–Mangostin Dye Adsorbed On Titanium Dioxide Electrode In Dsscs Application, Kanthira Kaewsud
Chulalongkorn University Theses and Dissertations (Chula ETD)
Conformations of α–mangostin dye (1,3,6–Trihydroxy–7–methoxy–2,8–bis(3–methyl–2–buten–1–yl)–9H–xanthen–9–one) were studied and three conformers were found as three co-existing species in various media (in vacuo, acetonitrile and water). Geometries, electronic structures and UV–Vis spectra of all conformers in various media have been obtained using density functional theory (DFT) and time–dependent DFT (TD–DFT) methods. The conformers of α–mangostin dye were inspected as photosensitizers for application in dye sensitized solar cells (DSSCs) and their light–harvesting efficiencies (LHEs) within the range of 0.6757–0.7556 eV (in vacuo), 0.8286–0.8466 eV (in acetonitrile) and 0.8288–0.8465 eV (in water) were obtained. The open circuit voltage (VOC) of three conformers within the …
Speciation Of Arsenic Using Sulfur Containing Ligand And Cotton Wool By Icp-Oes, Kavee Triteeyaprasert
Speciation Of Arsenic Using Sulfur Containing Ligand And Cotton Wool By Icp-Oes, Kavee Triteeyaprasert
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aimed to develop a method for speciation of arsenic species including As(III) and As(V) in environmental samples. Cotton wool and sulfur containing ligands including ammonium pyrrolidinedithiocarbarmate (APDC), L–cysteine and diethyldithiocarbamic acid were used in a solid phase extraction and determination of arsenic by using inductively coupled plasma optical emission spectrometry. The separation parameters were studied including pH, ligand concentration, cotton amount, type of eluents and flow rate. It was found that at pH 2, 0.1% APDC concentration and 0.5 g of cotton, As(III) could form complex with APDC (As(III) – APDC) and was separated from As(V) by using …
Green Synthesis Of Gold Nanoparticles Using Wax Leaved Climber Cryptolepis Buchanani Latex And Biological Activities, Kittiphong Tongsuk
Green Synthesis Of Gold Nanoparticles Using Wax Leaved Climber Cryptolepis Buchanani Latex And Biological Activities, Kittiphong Tongsuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Gold nanoparticles (AuNPs) is the one of nanodrug carriers that have been popular in the current trend. To prepare AuNPs for biomedical applications, many techniques have been developed. However, both physical and chemical methods may cause energy consuming and toxic residues so green synthesis would be the most appropriate method for the preparation of AuNPs. The green synthesis of AuNPs could be provided by utilizing of fungi, bacteria and plant. In this work, we focused to use plant latex as reducing and stabilizing agents for the synthesis of AuNPs. The latex was collected from Cryptolepis buchanani, a folk medicinal plant …
Sequence Specific Nucleic Acid Sensing By Pyrrolidinyl Peptide Nucleic Acid And Nanomaterials, Kriangsak Faikhruea
Sequence Specific Nucleic Acid Sensing By Pyrrolidinyl Peptide Nucleic Acid And Nanomaterials, Kriangsak Faikhruea
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, fluorescence and colorimetric nucleic acid sensing platforms based on pyrrolidinyl peptide nucleic acid (acpcPNA) probe and nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), gold nanoparticles (AuNPs), and silver nanoparticles (AgNPs) were developed. The acpcPNA probe was modified by multiple lysine residues to provide positive charges which enhanced the adsorption of the probe to various types of nanomaterials. In fluorescence detection mode, this results in higher quenching efficiency, resulting in lower background signal. Recovery of the quenched fluorescence signal was achieved upon hybridization with the complementary DNA/RNA target due to the displacement of the probe from …
C-O Bond Formation On C-5 Of 2,4-Diaminopyrimidines, Natthakorn Uppatam
C-O Bond Formation On C-5 Of 2,4-Diaminopyrimidines, Natthakorn Uppatam
Chulalongkorn University Theses and Dissertations (Chula ETD)
This work aims to find a robust oxidation condition that can efficiently convert 2,4-diaminopyrimidines to its C5-hydroxylated derivative. Although Boyland-Sims oxidation of these substrates has been reported, this procedure suffers low yield and poor reproducibility. The conditions for Boyland-Sims oxidation of 2,4-diaminopyrimidines were thus re-optimized. The parameters that could affect the yields of the 5-hydroxy products were investigated using 2,4-diamino-6-ethylpyrimidine as a model compound. The reactions were performed at 0.10 mmol scale of the starting pyrimidine. The yields of the products were monitored by 1H NMR spectroscopy with reference to an internal standard. The reaction was reproduced at larger scale …
Synthesis Of Hydroxyapatite Nanoparticles For Polynucleotides Delivery In Dentistry, Natthaya Thepphanao
Synthesis Of Hydroxyapatite Nanoparticles For Polynucleotides Delivery In Dentistry, Natthaya Thepphanao
Chulalongkorn University Theses and Dissertations (Chula ETD)
Hydroxyapatite (HAp) nanoparticles-based miRNA delivery system has emerged as a promising therapeutic agent for bone regeneration application. In order to achieve high therapeutic performance, the development of HAp functions remains challenging. This study describes the influence of HAp characters on their biological activities with osteoblast cell by synthesized different sizes of rod-like HAp with 150-200 and 100 nm in size and the different shape of elongated particles with 100-150 nm in size. A comparison was carried out on cytotoxicity, cellular uptake, and miRNA binding capacities. The elongated and rod-like shapes of 100-150 nm illustrated the high cell viability, and interestingly, …
Glycosylation Of Thioglycosides With Bromodiethylsulfonium Bromopentachloroantimonate As Novel Activator, Ladawan Punrum
Glycosylation Of Thioglycosides With Bromodiethylsulfonium Bromopentachloroantimonate As Novel Activator, Ladawan Punrum
Chulalongkorn University Theses and Dissertations (Chula ETD)
Glycosylation is an important reaction in carbohydrate synthesis of complex molecules such as oligosaccharides, glycoproteins, and glycolipids. Thioglycosides are widely used as precursors in oligosaccharide synthesis due to their ease of preparation, high stability towards protecting group manipulations and variety of activation methods. Recently, bromodiethylsulfonium bromopentachloroantimonate (BDSB) was reported as a novel source of highly electrophilic bromine. It was used to efficiently initiate cation-π cyclizations of polyene at low temperature. Herein, we report a chemical glycosylation of thioglycosides activated by BDSB. Firstly, armed and disarmed glycosyl donors and glycosyl acceptors were synthesized by using modified previous method. Next, several reaction …
Metalloporphyrin-Sensitized Titania/Silica/Iron Oxide Nanocomposites And Their Photocatalytic Activities, Padtaraporn Chanhom
Metalloporphyrin-Sensitized Titania/Silica/Iron Oxide Nanocomposites And Their Photocatalytic Activities, Padtaraporn Chanhom
Chulalongkorn University Theses and Dissertations (Chula ETD)
New nanomaterials of the magnetic visible light active photocatalysts, tetra(4-carboxyphenyl)porphyrin (TCPP) with different metals [Mn(II), Fe(III), Cu(II), Zn(II) and metal-free] in the center adsorbed on titania-silica-iron oxide superparamagnetic composites (TSI) were synthesized successfully. The photocatalytic activities in methylene blue (MB) degradation were determined under incandescent lamp for 3 h. Their characteristics have been identified using UV-visible spectroscopy, X-ray diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The photodegradation results revealed that the metalloporphyrin sensitization helped TSI to absorb the light in visible region. Titania-silica-iron oxide nanomaterials with copper(II) tetra(4-carboxyphenyl)porphyrin (CuTCPP) can significantly …
Molecular Simulations Of Voltage-Gated Proton-Selective Channel, Panisak Boonamnaj
Molecular Simulations Of Voltage-Gated Proton-Selective Channel, Panisak Boonamnaj
Chulalongkorn University Theses and Dissertations (Chula ETD)
Voltage-gated proton-selective channels (Hv1) are a membrane protein that permeates proton across cell membranes. They play an important role in various physiological processes. Hv1 was found as a dimer in membranes. Molecular mechanisms underlying the proton conduction of Hv1 have been a subject of intense research but is still remained unclear. In this study, molecular dynamics (MD) simulations of Hv1 were carried out to gain better understanding of the structure-function relationship. The first part of this thesis involved with an investigation of the role of the C-terminal domain (CTD) in stabilizing the dimer structure of Hv1. MD data showed the …
Fluorescent Sensors From Salicylaldimine Derivatives For Metal Ions, Phoom Sangsuwan
Fluorescent Sensors From Salicylaldimine Derivatives For Metal Ions, Phoom Sangsuwan
Chulalongkorn University Theses and Dissertations (Chula ETD)
An in-situ forming and sensing was developed as a high-throughput screening of fluorescent chemosensors for metal ions. The 45 salicylaldimines, formed in-situ from the condensation between 5 salicylaldehydes and 9 amines, in 96 well-plates were photographed under black light along with the 5 salicylaldehydes in the absence and presence of 18 metal ions. The library of fluorescence response images of these 50 chemosensors were processed into RGB values. The PCA of theΔRGB, the differences between those of images with and without the metal ions, showed 9 sensors with normalized loading value over 70%. The sensor array constructed from these 9 …
Hybrid Materials From Covalent Organic Frameworks And Ionic Liquids, Ranida Maliyaem
Hybrid Materials From Covalent Organic Frameworks And Ionic Liquids, Ranida Maliyaem
Chulalongkorn University Theses and Dissertations (Chula ETD)
Covalent organic frameworks (COFs) are new type material, whereby their wide range of properties derived from the chemistry of frameworks and their regular porosity. Here in, we reported the successful syntheses of the novel hybrid materials between porous COF material and ionic liquids (ILs). The crystalline porous powder of boroxine‑based COF, so called COF‑5, is reproducible via a condensation reaction between hexahydroxyltriphenylene and phenyldiboronic acid under a mild condition using a conventional heating method. The as‑synthesized COF-5 was characterized with PXRD, FT-IR, TGA and BET techniques, showing that the material contained 1D regular channels caused by π-π stacking of the …