Monvisade, Pathavuth
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Monvisade, Pathavuth
Alternative Name
Monvisade, P.
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Email
pathavuth.mo@kmitl.ac.th
16 results
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Item type:Publication, Preparation of hydroxyapatite/poly(methyl methacrylate) and calcium silicate/poly(methyl methacrylate) interpenetrating hybrid composites(2007-10-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hydrothermal growth of ZnO nanostructures from nano-ZnO seeded in P(MMA-co-BA) matrix(2011-11-01); ; Nookaew, JitiNano-ZnO synthesized by hydrothermal reaction were embedded in poly(methyl methacrylate-co-butyl acrylate) matrix (P(MMA-co-BA)) to produce the nano-ZnO/P(MMA-co-BA) nanocomposites via in-situ polymerization at 85 °C. The nano-ZnO/P(MMA-co-BA) nanocomposites were hydrothermal treated in the mixture solution of Zn(NO <inf>3</inf>) <inf>2</inf>•6H <inf>2</inf>O and NH <inf>4</inf>OH at 90 °C under various pH (i.e.7, 8, 9 and 10) and treatment time (i.e. 4, 6, 8, 10, 12 and 24 hrs). The nano-ZnO could act as seeding particles for hydrothermal growth of ZnO nanostructures on the surfaces of nanocomposites. The higher pH of basic solutions used in the hydrothermal treatment, the higher amount of Zn(OH) <inf>4</inf> <sup>2-</sup> nuclei would be created, leading to a modification of the ZnO morphology from nano-nuclei to nanorods, nanorods bushes (flower-like nanostructure) and nanofibers with nanospine. The increase of hydrothermal treatment time resulted in the increases of amount and length of multidirectional grown ZnO nanorods. Data of the contact angle measurement exhibited the increase of hydrophobicity of the nano-ZnO/P(MMA-co-BA) nanocomposites after hydrothermal growth of ZnO nanostructures. The nanocomposites treated at pH∈=∈10 for 24 hrs shows the highest hydrophobicity with the contact angle of 121. In addition, the thermal stability of the nano-ZnO/P(MMA-co-BA) could be improved by the formation of hydrothermal grown ZnO nanostructure on the nanocomposite surface. © 2011 Springer Science+Business Media B.V. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation and characterization of hydroxyapatite/poly(ethylene adipate) hybrid composites(2008-06-01); Hydroxyapatite/poly(ethylene adipate) (HAp/PEA) composites were prepared by in situ ring-opening polymerization of cyclic oligo(ethylene adipate) (C-OEA) within the porous HAp templates. HAp was firstly prepared by a co-precipitation method using calcium hydroxide and phosphoric acid and then shaped as a rectangular porous template. PEA precursor was synthesized by bulk polymerization of dimethyl adipate and ethylene glycol in the presence of tetraisopropyl orthotitanate. C-OEA was obtained by cyclo-depolymerization of the PEA precursor under high dilution condition using dibutyl tinoxide as a catalyst. The HAp/PEA composites were prepared by immersing the porous HAp templates in the mixture solution of C-OEA and dibutyl tinoxide catalyst overnight and ring-opening polymerizing at 180, 200 and 220°C for 24 h. The ring-opening polymerized PEA formed as a thin film coating on the surface of porous HAp template. The HAp/PEA composites contained PEA in the range of 20-26 wt%. The weight-average molecular weights of ring-opening polymerized PEA were in the range of 3800-4450 g/mol. Compressive strength of the HAp/PEA composite was significantly increased from 25 MPa in the porous HAp template to 140 MPa in the composite. © 2008 VSP. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Poly(ethylene terephthalate)/hydroxyapatite biomaterials: Preparation, characterization, and in vitro bioactivity(2009-02-01); Poly(ethylene terephthalate)/hydroxyapatite (PET/HAp) composites were prepared by mixing HAp powder with a mixture solution of cyclic oligo(ethylene terephthalate) (C-OET) and dibutyl tinoxide catalyst in dichrolomethane, and then shaping the precomposites in cylindrical pellets. The C-OET in the precomposites was ring-opening polymerized (ROP) to PET under vacuum at 250°C for 24 h. The PET/HAp composites were formulated with HAp to PET ratios of 60:40 (H6P4) and 50:50 (H5P5). The ROP-PET in the composites was present as a thin-layer coating on the HAp grains and evenly distributed throughout the samples. Compressive strength of the PET/HAp composites was significantly increased from 8 MPa of the H10P0 to 17 and 29 MPa for H6P4 and H5P5, respectively. In vitro bioactivity of the PET/HAp composites was studied by soaking in simulated body fluid (SBF) at 36.5°C for 7-28 days. After prolonged soaking, the HAp nanocrystals precipitated from the SBF solution and formed as a layer of globular aggregates, coated on the composite surfaces. The H6P4 composite showed faster formation rate of nano-HAp than the H5P5 composite, indicating that the bioactivity of PET/HAp composites depended on the amount of HAp. © 2008 Wiley Periodicals, Inc. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced Photocatalytic and Biological Properties of Cellulose Cotton Fabric Coated with Carboxyethyl Chitosan/Zinc Oxide Bio-nanocomposite(2025-09-01); This study developed a CECS/ZnO-functionalized cotton fiber sheets as a single-use filter layer for face masks, with enhanced antibacterial and photocatalytic properties. Cotton fiber sheets were modified with zinc oxide nanoparticles (ZnO NPs) using a dip-coating method, with and without carboxyethyl chitosan (CECS) as a binder and stabilizing agent. The fiber sheets were treated with 0.1, 0.3, and 0.5 M Zn(NO<inf>3</inf>)<inf>2</inf> solutions, followed by hydrothermal synthesis in NH<inf>4</inf>OH (Zn:NH<inf>4</inf>OH = 1:2) at 100 °C for 1 h. The study successfully demonstrated ZnO NPs formation on cotton sheets, producing ZnO-immobilized cotton sheets (Cf/Zn). Higher Zn<sup>2</sup>⁺ concentrations promoted greater nucleation of ZnO nanoparticles. However, they also caused particle agglomeration, which reduced the surface area and weakened ZnO adhesion to the cotton fibers. This presents a significant challenge in achieving a uniform nanoparticle distribution. However, the introduction of carboxyethyl chitosan (CECS) (Cf/CECS/Zn) as a binder and stabilizer represents a novel approach that showed a superior ZnO adhesion, better particle distribution, and higher Zn content than untreated Cf/Zn. Among the samples, Cf/CECS/Zn0.1 exhibited the highest Zn content (154 ppm), the highest antibacterial zone diameter (29.39 mm), and the most effective photocatalytic activity (65.66%). While both Cf/Zn and Cf/CECS/Zn demonstrated antibacterial activity against S. aureus, Cf/CECS/Zn0.1 showed superior performance, with low cytotoxicity confirmed by Vero cell viability tests. The treated fibers also displayed enhanced hydrophobic and photocatalytic properties. These results demonstrate the potential of CECS-modified ZnO-immobilized cotton sheets for advanced healthcare filtration applications, offering enhanced antibacterial, photocatalytic, and non-toxic properties. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mechanical properties and bioactivity of calcium silicate/poly(ethylene terephthalateco-caprolactone) composites(2013-12-01); Calcium silicate/poly(ethylene terephthalate-co-caprolactone) (CS/PET-co-PCL) composites were prepared via ring opening polymerisation (ROP) technique. The CS/PET-co-PCL composites were prepared by mixing 60 wt-% of CS, 40 wt-% of cyclics and dibutyl tinoxide catalyst (3 mol.-% with respect to cyclics). The cyclics consisted of the mixture of cyclic oligo(ethylene terephthalate) (COET) and e-caprolactone (CPL) with varying molar ratio of C-OET/CPL, i.e. 7 : 3, 8 : 2 and 9 : 1. The precomposites were then ring opening polymerised at 200°C for 24 h. The ROP-PET-co-PCL in the composites was present as a continuous phase impregnated with the CS particles. The 1HNMR spectra of ROP-PET-co-PCL extracted from the CS/PET-co-PCL composites showed heterolinkage signals between PET and PCL at d 4·4 and d 4·6 ppm, indicating successful copolymerisation. When the PCL content increased, the ROP-PET-co-PCL changed in the copolymer structure from block to random structure. The presence of CS powders in the CS/PETco- PCL composites resulted in high stiffness of the composites and inhibited heat dissipation during the dynamic mechanical analysis performed between 250 and 200°C. The compressive strengths of all the composites were in the range of 16-21 MPa. The higher the PET content, the stronger the CS/PET-co-PCL composites obtained. Composites containing 9 : 1 of C-OET/CPL polymerised at 200°C possessed the highest compressive strengths of 21·3 MPa, falling in the range of cartilage bone, i.e. 14-59 MPa. Bioactivities of the CS/PET-co-PCL composites were studied by soaking in simulated body fluid for 7 days. All CS/PET-co-PCL composites could induce the formation of hydroxyapatite nanocrystals on the composite surfaces, indicating the bioactivity of the CS/PET-co-PCL composites. © W. S. Maney & Son Ltd. 2013. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, In situ ring-opening polymerization of hydroxyapatite/poly(ethylene adipate)-co-(ethylene terephthalate) biomimetic composites(2013-02-01); Hydroxyapatite/poly(ethylene adipate)-co-poly(ethylene terephthalate) biomaterials (HAp/PEA-co-PET) have been prepared by ring opening polymerization (ROP) of cyclic oligo(ethylene adipate)-co-oligo(ethylene terephthalate) (C-OEA-co-C-OET) in the porous hydroxyapatite (HAp) scaffolds at 250 °C for 24 h under vacuum. The content of ROP-PEA-co-PET in the HAp/PEA-co-PET composite was about 20 wt% with the values of number average molecular weight (Mn) and weight average molecular weight (MW) of 3380 and 7160 g/mol, respectively. Compressive strength and modulus of the HAp/PEA-co-PET composites were about 29 and 246 MPa, respectively. These mechanical properties were higher than those of the porous HAp templates and natural cancellous bone. In vitro bioactivity of the HAp/PEA-co-PET composites was studied by soaking in simulated body fluid (SBF) under the flowing system at the rate of 130 mL/day for 7, 14, 21 and 28 days. The formation of hydroxyapatite nanocrystals was observed on the composite surfaces through the consumption of calcium and phosphorus from the SBF solution, indicating the bioactivity of these HAp/PEA-co-PET composites. These results indicated the competency of HAp/PEA-co-PET composites for biomedical applications. © Indian Academy of Sciences. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Poly(methyl methacrylate-co-butyl acrylate)/organophosphate-modified montmorillonite composites(2011-11-03); ; Poly(methyl methacrylate-co-butyl acrylate)/tetrabutylphosphonium modified montmorillonite (P(MMA-co-BA)/P-MMT) composite films were prepared by simple solution casting technique. P(MMA-co-BA) was synthesized through solution polymerization in the presence of benzoyl peroxide (BPO) as an initiator. After modification via cation exchange reaction by tetrabutylphosphonium bromide, the organoclay was dispersed in toluene and added into P(MMA-co-BA) solution. The well-dispersed mixture was cast by doctor blade technique to obtain the composite films. The P-MMT content in the composites was varied (i.e., 1, 2, 3 and 6 wt%) in order to study its effects on thermal stability, mechanical properties and UV shielding ability. The structure of P-MMT in the composites was investigated by XRD technique. The composites containing 1 and 2 wt% of P-MMT showed the d<inf>001</inf> peak slightly shifted to lower 2θ, indicating mainly intercalated structure occurred with some agglomerations of particles. The intercalated structure of P(MMA-co-BA)/P-MMT 2% composites was observed by TEM technique. The TGA results showed that degradation of the composites occurred at higher temperatures compared to that of their virgin polymer and the degradation point increased with P-MMT content. Tensile strength and Young's modulus of composites were higher than those of their original copolymer. By addition of 1-3 wt% of P-MMT, it could be seen that the higher the P-MMT loading, the higher would be the tensile strength and Young's modulus. The P(MMA-co-BA)/P-MMT composite films showed their screening ability in UV region, especially in the UV-B range, which is rather higher than that in the visible region. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation and characterization of hydroxyapatite/poly(ethylene glutarate) biomaterials(2007-05-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Water-soluble chitosan intercalated montmorillonite nanocomposites for removal of basic blue 66 and basic yellow 1 from aqueous solution(2013-04-05); ; Water-soluble chitosan intercalated montmorillonite (wCTS/MMT) nanocomposites were modified and characterized by using Fourier transform infrared, thermogravimetric analysis, and X-ray diffractometer techniques. Two types of wCTS, namely, low molecular-weight chitosan (L-wCTS) and hydroxyethylacryl chitosan (H-wCTS) were synthesized and applied. The batch adsorption experiments on these nanocomposites were conducted by using basic dyes, that is, Basic Blue 66 and Basic Yellow 1 (BY1). The adsorption capacities of sodium montmorillonite (Na-MMT), chitosan, L-wCTS/MMT, and H-wCTS/MMT were measured and compared. The results showed that the adsorption capacities of wCTS/MMT nanocomposites were higher than those values of Na-MMT and chitosan. The adsorption kinetics of wCTS/MMT nanocomposites for BY1 were studied. It was described that the adsorption processes were better fitted by pseudo-second-order equation. The Langmuir and the Freundlich models were used to fit the adsorption isotherm. It was indicated that the adsorption isotherms followed the Langmuir model. The values of the maximum adsorption capacity of L-wCTS/MMT and H-wCTS/MMT adsorbents were at 188.7 and 294.1 mg/g, respectively. © 2012 Wiley Periodicals, Inc.