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2017

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Investigation Of Asphaltene Aggregation Kinetics In The Presence Of Water-In-Oil Emulsion, Penpitcha Roengsamut Jan 2017

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 …

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Study On Energy Storage Ability Of Zno/Tio2 For Photocatalytic Degradation Of Isopropanol, Ratchawan Jarumanee Jan 2017

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 …

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Vegetable Oil Based Microemulsion Biofuels, U-Larak Peson Jan 2017

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 …

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Improvement Of Life Cycle Assessment Software And Its Applications, Yodsathorn Chavewanmas Jan 2017

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 …

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Metal-Salen Derivatives For Electro-Reduction Of Carbon Dioxide, Kantima Chitchak Jan 2017

Metal-Salen Derivatives For Electro-Reduction Of Carbon Dioxide, Kantima Chitchak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Copper(II) salen, salophen-based ligands, and their corresponding copper complexes were prepared and utilized for the electrocatalytic reduction of carbon dioxide. Controlled-potential electrolysis of copper(II) salen electrocatalyst with carbon dioxide in non-aqueous solution was investigated to obtain the optimized electrolysis condition including the applied potential and proton donor quantity. With the applied potential of –2.10 V, carbon monoxide (3.50-16.30%) was obtained as the only product in gas phase. Methane was additionally found with the addition of proton donor and its maximum percentage (0.39 ± 0.00%) were obtained from the electrolysis with 25.00 mM proton donor and 2.00 mM copper(II) salen. Moreover, …

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Synthesis Of Ni-Tin Incorporated Porous Silica Catalysts For Dry Reforming Of Methane, Maslin Chotirach Jan 2017

Synthesis Of Ni-Tin Incorporated Porous Silica Catalysts For Dry Reforming Of Methane, Maslin Chotirach

Chulalongkorn University Theses and Dissertations (Chula ETD)

A new titanium nitride (TiN) promoted nickel catalyst was synthesized and tested as an alternative catalyst in the dry reforming of methane (DRM). The series of this catalyst with various Ni and TiN contents was prepared in two steps, direct synthesis of SBA-15 in the presence of TiN, followed by the impregnation of Ni. The influence of TiN promoted Ni-based catalyst on dry reforming reaction was investigated at the temperature of 700ºC and atmospheric pressure for a duration of 4 h, using feed ratio of CH4/CO2 = 1. The promising catalysts, that gave highest CO2 and CH4 conversions as well …

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Electrochemical Properties Of Lnsr3-Xcaxfe3-Ybyo10 (Ln = La, Pr And Sm; X = 0-1.0; B = Co, Ni And Cu; Y = 0-1.5) For Intermediate Temperature Solid Oxide Fuel Cells, Nicharee Wongsawatgul Jan 2017

Electrochemical Properties Of Lnsr3-Xcaxfe3-Ybyo10 (Ln = La, Pr And Sm; X = 0-1.0; B = Co, Ni And Cu; Y = 0-1.5) For Intermediate Temperature Solid Oxide Fuel Cells, Nicharee Wongsawatgul

Chulalongkorn University Theses and Dissertations (Chula ETD)

To enhance the electrochemical performance of cathode material for intermediate temperature solid oxide fuel cell (IT-SOFC) the Ruddlesden-Popper (RP) phases of LnSr3-xCaxFe3-yByO10 (Ln = La, Pr and Sm; x = 0-1.0; B = Ni, Co, and Cu; y = 0-1.5) was investigated and prepared by citric nitrate combustion method. Firstly, various Ca concentrations were added to the LaSr3-xCaxFe3O10-δ structure and it was found that the materials contained low Ca concentration provided the lower area specific resistance (ASR) and better electrochemical cell performance due to the enhance in conductivity and reduction of TEC. Secondly, the effect of Pr and Sm replacement …

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Electrochemical Sensors For Human Papillomavirus Dna, C-Reactive Protein And Food Colorants Detections, Sakda Jampasa Jan 2017

Electrochemical Sensors For Human Papillomavirus Dna, C-Reactive Protein And Food Colorants Detections, Sakda Jampasa

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this dissertation, electrochemical sensors for determination of medical biomolecular markers and food colorants were developed. The research can be divided into two parts. In the first part, electrochemical sensors for determination of clinically important biomarkers were studied. There was two subprojects based on the target markers. The first subproject was the development of electrochemical sensor for the simultaneous detection of high-risk human papillomaviruses (HPV) DNA type 16 and 18 as biomarkers for cervical cancer. In this work, a highly specific pyrrolidinyl peptide nucleic acid was employed as DNA capture probe for both target DNAs. A second PNA probe labeled …

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Fecu/Sio2 Catalysts Prepared By Autocombustion Method For Fischer-Tropsch Synthesis, Suthasinee Pengnarapat Jan 2017

Fecu/Sio2 Catalysts Prepared By Autocombustion Method For Fischer-Tropsch Synthesis, Suthasinee Pengnarapat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study was to prepare iron-based catalysts supported on silica by autocombustion method for directly using for Fischer-Tropsch synthesis (FTS) without a reduction step. The effect of different citric acid (CA):iron nitrate (N) molar ratios (CA:N), acid types and SiO2 supports on the FTS performance of catalysts were investigated. The CA:N had an important influence on the formation of iron active phases (FexC) and FTS activity. Increasing the CA:N molar ratios up to 0.1 increased CO conversion of catalyst to 86.5%, which was then decreased markedly at higher CA:N molar ratios. An excess of CA resulted in …

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Microencapsulation Of Eugenol In Polyelectrolyte Complexes Of Chitosan And Alginate, Chamaiporn Supachettapun Jan 2017

Microencapsulation Of Eugenol In Polyelectrolyte Complexes Of Chitosan And Alginate, Chamaiporn Supachettapun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Eugenol is widely used in several applications such as food activity packaging to prolong shelf life of fruits and vegetables because of its antimicrobial activity. However, eugenol is easy to decompose, leading to reduce its activity. In this work, we prepared eugenol loaded alginate-chitosan microparticles in order to solve this problem and controlled release essential oil using ionic gelation technique. The effect of concentration of eugenol (0.1-0.5 g), calcium chloride (0.5 – 8 %W/V) and surfactant (2-10% W/V) was investigated. The results showed that the optimum condition was eugenol 0.1 g, calcium chloride 2% W/V and surfactant 4% W/V. The …

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Functional Surfactants In Lubricant For Microelectronic Industry, Chuenkamol Khongphow Jan 2017

Functional Surfactants In Lubricant For Microelectronic Industry, Chuenkamol Khongphow

Chulalongkorn University Theses and Dissertations (Chula ETD)

The functional surfactants, as the additional additives in the standard glycol-based lubricant were studied and optimized to reduce and protect the surface of the magnetic read/write head from deposited contaminants during the lapping processes. The scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) results identified that the black contamination was bismuth (Bi) particles, came out from lapping plate during the lapping process due to wear. Selected surfactants exhibited the results in reduce and prevent the deposition of contaminants by forming the micelle beyond their critical micelle concentration (CMC) values. We found that both polyethoxylate alcohol (PEAL) and quaternary amines …

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Synthesis Of Puerarin-Gold Nanoparticles For Transdermal Delivery, Kwanruen Chanpeng Jan 2017

Synthesis Of Puerarin-Gold Nanoparticles For Transdermal Delivery, Kwanruen Chanpeng

Chulalongkorn University Theses and Dissertations (Chula ETD)

Puerarin (Pur) is herbal medicine that its inflammatory response but low solubility to reduce activity. Thus, the aim of this study was to synthesize q188-kappa-carrageenan@Pur@gold nanoparticles (q188-κ-c@Pur@AuNPs) for enhancing solubility and transdermal delivery. The κ-c was synthesized by quaternization of κ-c with 25% (v/v) q188, and the q188-κ-c @AuNPs was prepared by reducing HAuCl4 into AuNPs by using 25% (v/v) q188-κ-c as reducing and stabilizing agents. The highest degree of quaternization (%DQ) at 21.12% was found q188 addition, which was calculated from 1H NMR. The solubility of the q188-κ-c derivatives was 43.7±0.01%, which higher than κ-c. The size of synthesized …

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Effect Of Corrosion Inhibitors In Lubricant For Electronic Industry, Natclitta Maipul Jan 2017

Effect Of Corrosion Inhibitors In Lubricant For Electronic Industry, Natclitta Maipul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The selected functional polymers and fatty esters of poly)1-butene pyrrolidone) (PP) and propylene glycol monostearate (PG) were investigated and applied to use as the corrosion inhibitors for protecting material removal during read/write head lapping processes in hard disk drive (HDD) production. Potentiodynamic polarization measurement was used to study their corrosion behaviors against antiferromagnetic materials (IrMn) which are the most sensitive materials in the head structure. Corrosion rate of PP- and PG-modified lubricants were 0.086 and 0.084 Å/min, respectively, while standard lubricant was 0.111 Å/min. Moreover, the leaching out of metallic atoms was investigated by using inductively couple plasma mass spectroscopy …

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Mixed Metal Oxide Catalysts Derived From Natural Sources For Production Of Fatty Acid Methyl Esters, Wayu Jindapon Jan 2017

Mixed Metal Oxide Catalysts Derived From Natural Sources For Production Of Fatty Acid Methyl Esters, Wayu Jindapon

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objectives of this research are to study active sites of Ca-based catalysts derived from calcite (CaCO3) and dolomite (CaMg(CO3)2), and to clarify catalytic effect of MgO in the calcined dolomite as catalyst in transesterification of palm oil with methanol. Firstly, the effects of calcination temperature on evolution of MgO in dolomite and its catalytic activity were studied. The MgO containing in the calcined dolomite was not active, while the main active site was CaO. However, Ca and Mg mixed oxides obtained from calcined dolomite had higher activity than that prepared by physical mixing in which calcite and magnesite (MgCO3) …

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Hydrodeoxygenation Of Oleic Acid On Unsupported Co-Mo And Ni-Mo Sulfide Catalysts, Paphawee Sanggam Jan 2017

Hydrodeoxygenation Of Oleic Acid On Unsupported Co-Mo And Ni-Mo Sulfide Catalysts, Paphawee Sanggam

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, hydrodeoxygenation (HDO) of oleic acid (model compound of palm oil) over unsupported Co-Mo and Ni-Mo sulfide catalysts was carried out in Parr reactor to produce bio-hydrogenated diesel (BHD). The effects of reaction parameters: temperature, hydrogen pressure and the mole ratio of catalysts (Ni/(Ni+Mo) or Co/(Co+Mo)) on the conversion and product yields (mainly n-C17 and n-C18 hydrocarbons) were investigated to find the optimal conditions. The results showed that high pressure favored a HDO pathway, while high temperature strongly affected to decarboxylation and decarbonylation pathways. At optimal condition as temperature of 280oC, reaction times of 6 h and hydrogen …

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Preparation Of Porous Carbon From Popped Rice Via Impregnated Water Coupled With Freeze-Drying Process, Purichaya Nisawa-Anutaraphan Jan 2017

Preparation Of Porous Carbon From Popped Rice Via Impregnated Water Coupled With Freeze-Drying Process, Purichaya Nisawa-Anutaraphan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Activated carbon is an interesting material due to its high surface area derived from the highly porous structure. This material is suitable for using as a good adsorbent in various applications such as wastewater treatment, gas absorption and medicine. Production of activated carbon typically consists of two steps which are carbonization and activation. Agricultural wastes are used as carbon sources. This research focuses on the production of activated carbon from popped rice due to its appropriate chemical and structural characteristics, including highly starch content and connected-pore structure. Therefore, it should potentially be applied to produce activated carbon if the surface …

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Photooxidation Of Organosulfur Compounds Catalyzed By Iodo-Bodipy Derivatives Under Visible Light Irradiation, Piyamaporn Tangkasemsamran Jan 2017

Photooxidation Of Organosulfur Compounds Catalyzed By Iodo-Bodipy Derivatives Under Visible Light Irradiation, Piyamaporn Tangkasemsamran

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, iodo-BODIPY derivatives, I-GB, 3I-GB, I-RB, were synthesized and used as photocatalysts for oxidation of organosulfurs such as thiols and thioethers into the corresponding disulfides and sulfoxides, respectively, as well as compared with benchmark photocatalyst, rose bengal. All BODIPY derivatives were successfully synthesized in good yields (36-80%) via condensation reaction between 4-iodobenzaldehyde and corresponding pyrroles, followed by oxidation with DDQ and complexation with BF3.OEt2. Among all synthesized BODIPYs, 3I-GB and 3I-RB showed relatively low quantum yield (0.053-0.054) with high singlet oxygen generation efficiency under green LED suggesting that both of them could serve as good photocatalysts for sulfur …

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Development Of Hydrogen Embrittlement Resisted Pd-Cu Alloy Membrane, Ratchaneekorn Chukiatthai Jan 2017

Development Of Hydrogen Embrittlement Resisted Pd-Cu Alloy Membrane, Ratchaneekorn Chukiatthai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The development of PdCu alloy membranes that can be used in hydrogen separation at low working temperature (<300°C) without hydrogen embrittlement problem is a very attractive topic for the petrochemical industry. Pd–Cu membranes have been prepared by electroless plating and electroplating method on stainless steel support. The compositions of the PdCu alloy membranes were related to both the metal deposition rates. The appropriate annealing temperature of Pd–Cu membranes was found at 500 °C in argon atmosphere for 24 hours to form a complete alloy material. After thermal annealing, the Cu atom was distributed in Pd alloy membrane. The surface morphology, compositions, and crystallinity of the PdCu alloy membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The best Pd contents in PdCu alloy membrane were about 84 and 75 %at. The hydrogen flux through the PdCu alloy membrane was measured at temperature 150 to 300 °C and differential pressure 0.5 to 2.5 bar for membrane stability. The hydrogen flux increased with increasing temperature and pressure. Adding Cu atoms in Pd can reduce strain in Pd lattice structure. Both PdCu alloy membrane can be operated at the lower temperature than a critical temperature of pure Pd membrane without hydrogen embrittlement.

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Effect Of Metallocene Elastomers And Screw Speed On Polypropylene Compounds: Morphological And Physical Properties, Supot Ponhan Jan 2017

Effect Of Metallocene Elastomers And Screw Speed On Polypropylene Compounds: Morphological And Physical Properties, Supot Ponhan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Polypropylene (PP) which is widely used in automotive industries can replace engineering plastics and metals due to its outstanding mechanical properties, moldability and reduced weight. Some automotive parts such as bumper require higher impact resistance, which is the limited property of PP. The aim of this work is to improve the impact properties with balancing the stiffness-impact properties and the physical properties by blending PP with metallocence elastomer (POE) using a twin screw extruder. The effects of PP and POE type and blending ratio on the PP/POE blends properties and morphology was studied. The results showed that the impact strength …

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Water/Dust Repellent Coatings For Wood Surface From 3-Aminopropyltriethoxy Silane-Quat 188, Tanate Tubtimtong Jan 2017

Water/Dust Repellent Coatings For Wood Surface From 3-Aminopropyltriethoxy Silane-Quat 188, Tanate Tubtimtong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Wetting and dust fouling on wood surface are big problems because of hydroxyl group and static charge on its surface. These problems could be minimized by surface modification which decreasing of hydroxyl groups and increasing of positive charges on wood surface. Many researches were reported about wetting issue but there were few studies directly involved to dust problem. In this research, 3-aminopropyltriethoxy silane (APTES) and 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (Q188) were used to modify hydroxyl groups on wood surface to enhance wetting and dust repellency behavior of wood. The APTES-treated woods (AW) were prepared by immersion solution method and then were …

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Molecular Dynamics Of Single-Wall Carbon Nanotube Wrapped With Polypropylene, Wanwisa Panman Jan 2017

Molecular Dynamics Of Single-Wall Carbon Nanotube Wrapped With Polypropylene, Wanwisa Panman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, the nanocomposite materials have been widely used in various applications due to their unique properties such as thermal and electrical properties. Polymer/carbon nanotube (CNT) nanocomposite is one the important nanocomposite materials that are manufactured for improving thermal conductivity and electrical properties of polymers. Unfortunately, polypropylene (PP)/CNT preparation is difficult because of CNT dispersion and aggregation. Accordingly, amylose (AMY) and chitosan (CS) are selected in the present study in order to demonstrate how AMY and CS could diminish such problems by non-covalent modification on outer surface of single-walled CNT using molecular dynamics (MD) simulations. The MD results reveal that AMY …

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Methane Adsorption By Carbon Molecular Sieve Derived From Polycarbonate And Polyaniline, Jakchai Thawornwatthanasirikul Jan 2017

Methane Adsorption By Carbon Molecular Sieve Derived From Polycarbonate And Polyaniline, Jakchai Thawornwatthanasirikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The adsorptions of methane by carbon molecular sieves (CMS) were investigated at 35°C and 45°C by volumetric apparatus with the pressure range from 0 to 800 psia. CMS was prepared from polymer precursors such as polycarbonate (PC) and polyaniline (PANI) by carbonization under nitrogen inert atmosphere and activation by CO2 at temperature 700, 800 and 900°C. The yield of CMS is decreased with increasing carbonization and activation temperature. The methane adsorption capacity at 35°C of CMS derived from PC is 2.82 mmol CH4/g. The methane adsorption of the samples from PC is higher than those obtained from PANI for the …

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Effect Of Oxygen-Containing Functional Groups On Methane Adsorption By Activated Carbon, Kittima Dheerapreampree Jan 2017

Effect Of Oxygen-Containing Functional Groups On Methane Adsorption By Activated Carbon, Kittima Dheerapreampree

Chulalongkorn University Theses and Dissertations (Chula ETD)

Natural gas has been applied as a fuel for vehicle because it is cheaper and cleaner burning than other fuels. In the vehicle, natural gas is ordinarily reserved by compressing and storing under high pressure at room temperature but this method has several limitations (e.g. low energy density, high weight of tank). Therefore, a porous material with high specific surface area (e.g. activated carbon) is suggested to eliminate the limitations of natural gas storage by compression, natural gas is adsorbed at relatively low pressure and room temperature. The adsorption capacity of activated carbons is related with their physical and chemical …

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The Incipient Layer Of Wax Deposit, Tunya Ketjuntiwa Jan 2017

The Incipient Layer Of Wax Deposit, Tunya Ketjuntiwa

Chulalongkorn University Theses and Dissertations (Chula ETD)

The formation of the incipient layer of wax deposit when waxy oil is exposed to a cold surface is studied. Using a cold-finger apparatus, the evolution of deposit thickness is monitored with a video camera, allowing one to resolve the deposit layer formation from inception up to long times where deposit thickness no longer times where deposit thickness no longer grows. Characterization of wax deposits show that incipient layer has identical composition to waxy oil, indicating that deposit is not formed by a diffusion process. Modelling shows deposit formation at the investigated conditions cannot be explained by a diffusion process.

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Material Flow Analysis (Mfa) Study For Sustainable Management Of Pvc Wastes In Thailand (Phase Iii), Wikanda Khomchu Jan 2017

Material Flow Analysis (Mfa) Study For Sustainable Management Of Pvc Wastes In Thailand (Phase Iii), Wikanda Khomchu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Polyvinyl chloride (PVC) products are used for domestic consumption more than 400,000 tons annually and tend to be increasing in Thailand. After discarded, these products will become wastes which are being accumulated and could cause several environmental problems if they are disposed by inappropriate method. In previous studies, our group investigated the material flow of PVC in Thailand to handle the PVC waste problems. Material Flow Analysis (MFA) model was developed to estimate the quantity and route of PVC wastes in Thailand. Furthermore, the primary data were collected from recycle shops and landfill sites were used to estimate the amount …

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Probiotic Properties And Anti-Helicobacter Pylori Activity Of Lactic Acid Bacteria From Plant And Fermented Food Products, Sujitra Techo Jan 2017

Probiotic Properties And Anti-Helicobacter Pylori Activity Of Lactic Acid Bacteria From Plant And Fermented Food Products, Sujitra Techo

Chulalongkorn University Theses and Dissertations (Chula ETD)

Two hundred and thirty-eight strains of lactic acid bacteria (LAB) isolated from several plant-materials and fermented food products collected in Thailand were screening for antibacterial activity. Fifty-three strains which exhibited antimicrobial activity against Helicobacter pylori clinical strains, were selected and identified based on the phenotypic, chemotaxonomic characteristics and 16S rRNA gene sequence analysis. They were identified as Lactobacillus (Lb.) plantarum subsp. plantarum (3 strains), Lb. pentosus (10 starins), Pediococcus (P.) pentosaceus (2 strains), Lb. paracasei subsp. tolerans (1 strain), Lb. fermentum (5 strains), Enterococcus (En.) faecium (2 strains), En. casseliflavus (1 strain), Lactococcus (Lc.) garvieae subsp. garvieae (1 strain), Lc. …

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Clinical Efficacy Of Biocellulose Wound Dressing Containing Silk Sericin And Polyhexamethylene Biguanide For Split-Thickness Skin Graft Donor Sites, Supamas Napavichayanun Jan 2017

Clinical Efficacy Of Biocellulose Wound Dressing Containing Silk Sericin And Polyhexamethylene Biguanide For Split-Thickness Skin Graft Donor Sites, Supamas Napavichayanun

Chulalongkorn University Theses and Dissertations (Chula ETD)

A biocellulose wound dressing composed of silk sericin as an accelerative wound healing component and polyhexamethylene biguanide (PHMB) as an antimicrobial agent which showed effective and safe wound treatment. A prospective, single-blinded, randomized controlled matched-pair study was designed to evaluate the safety and the clinical efficacy of the biocellulose wound dressing containing silk sericin and PHMB compared with Bactigras® in healthy volunteers (phase I clinical study) and in split-thickness skin graft (STSG) donor site wound treatment (phase II clinical study). There were 105 healthy volunteers in phase I clinical study. The results showed that the erythema and melanin levels of …

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Anti-Aging Activity Evaluation Of Grammatophyllum Speciosum Extract For Development Into An Anti-Wrinkle Serum, Verisa Chowjarean Jan 2017

Anti-Aging Activity Evaluation Of Grammatophyllum Speciosum Extract For Development Into An Anti-Wrinkle Serum, Verisa Chowjarean

Chulalongkorn University Theses and Dissertations (Chula ETD)

Grammatophyllum speciosum Blume (Orchidaceae) is a large-sized orchid in Southeast Asia. The aim of this study was to evaluate G. speciosum pseudobulb extract for anti-aging activities, both in vitro and in vivo. In vitro anti-aging activity was performed using non-cell and cell-based assays. In vitro study, G. speciosum pseudobulb extract exhibited a high content of gastrodin, which was used as an active analytical marker. The total content of the antioxidant polyphenols in G. speciosum ethanolic extract was 48.19 ± 0.39 mg epigallocatechin gallate (EGCG) equivalent / g extract. The anti-collagenase enzyme activity of the ethanolic extract of the pseudobulb of …

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Development Of Polyurethane Based Foam Dressing Impregnated With Silver Nanoparticles And Asiaticoside For Dermal Wound Treatment, Nantaporn Namviriyachote Jan 2017

Development Of Polyurethane Based Foam Dressing Impregnated With Silver Nanoparticles And Asiaticoside For Dermal Wound Treatment, Nantaporn Namviriyachote

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study was an innovation of polyurethane foam dressing containing silver nanoparticles and asiaticoside that aimed to treat dermal wounds. It consists of three essential properties; the natural polyols containing foam dressing could absorb exudate and maintain moisture in the wound bed, the silver could prevent and kill bacteria, the asiaticoside could accelerate wound healing. The foam dressing was produced and 2% of hydrophilic natural polyols of various types added. The characteristics were evaluated. Hydroxypropyl methylcellulose (HPMC), chitosan low MW (CLMW) and sodium alginate (Alg) were selected according to their high absorption capacity, low dehydration, good mechanical strength and low …

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Free Radical Scavengers From Dendrobium Palpebrae, Napat Kyokong Jan 2017

Free Radical Scavengers From Dendrobium Palpebrae, Napat Kyokong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Phytochemical study of Dendrobium palpebrae Lindl. (Orchidaceae) afforded ten pure compounds. One of them was characterized as a new phenanthrene-phenanthraquinone derivative named dendropalpebrone, and nine known compounds were identified as gigantol, lusianthridin, nobilone, 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene, 2,5-dihydroxy-4,9-dimethoxyphenanthrene, moscatilin, scoparone, 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl and dendroflorin. All of the isolated compounds were initially screened for their free radical scavenging activity via oxygen radical absorbance capacity assay, DPPH radical scavenging assay, deoxyribose degradation assay, and assay for intracellular antioxidant activity in H2O2-induced RAW 264.7 murine macrophage cells. Dendroflorin showed the most potent activity in all assays, especially in the deoxyribose degradation assay. It manifested an IC50 value …

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