Monvisade, Pathavuth
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Monvisade, Pathavuth
Alternative Name
Monvisade, P.
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pathavuth.mo@kmitl.ac.th
15 results
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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, In vitro drug release profiles of pH-sensitive hydroxyethylacryl chitosan/sodium alginate hydrogels using paracetamol as a soluble model drug(2017-06-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study on Crosslinked Structure and Thermal Properties of Polymer Networks Based on Tung Oil and PVA with Different Catalytic Systems(2017-04-01); Yamaguchi, MasayukiThis work focuses on the effect of different catalytic systems on network structures and thermal properties of the polymer networks from poly(vinyl alcohol) (PVA) and Tung oil. The polymer networks based on Tung oil and PVA using potassium persulfate (KPS) as a thermal catalyst or KPS and sodium thiosulfate as a redox catalyst were performed at 60 °C and 80 °C. FTIR results confirmed that Tung oil could be crosslinked by both catalysts. Moreover, at 60 °C, it can be seen that the crosslinking reaction with the redox catalyst could occur better than with the thermal catalyst. To prove the crosslinking reaction of PVA in the polymer networks, water resistance of the polymer networks was also investigated. It was found that the PVA was successfully crosslinked by thermal catalyst but was not by redox catalyst. Besides, from this result, it could be suggested that, in the redox system, structure of the polymer networks was mainly formed by Tung oil. From DMA results, T<inf>g</inf> of PVA with the thermal catalyst is higher than that with the redox catalyst because of the network formation of PVA in thermal catalytic system. While the T<inf>g</inf> of Tung oil in the polymer networks with the redox catalyst is higher than that with the thermal catalyst. This is reasonable because the crosslinking reaction of Tung oil with the redox catalyst could easily occur better than with the thermal catalyst. Altogether, crosslink structure of Tung oil exhibited major influence on properties of PVA/Tung oil polymer network. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The effect of glycerol/water and sorbitol/water on the plasticization of hydroxyethylacryl chitosan/sodium alginate films(2015-11-04); Yamaguchi, MasayukiThis research aimed to investigate on the effects of glycerol/water and sorbitol/water on the plasticization of hydroxyethylacryl chitosan (HC)/sodium alginate (SA) films. The HC/SA films were prepared with different amount of glycerol or sorbitol as a plasticizer (25, 40 and 50% w/w) and kept at different relative humidity (0% RH and 50% RH) in order to restrict the content of water within the films. The results from differential scanning calorimetry (DSC) showed the miscibility of polymer and plasticizers (glycerol and sorbitol) for all blend compositions. A remarkable reduction of glass transition temperature (T<inf>g</inf>) could be obtained by adding glycerol over 40% w/w. For sorbitol plasticized films, although the addition of sorbitol could reduce T<inf>g</inf>, it was still higher than room temperature. It was claimed that glycerol could gain more effective plasticizing than sorbitol in the HC/SA films. In the cooperation with water as co-plasticizer (glycerol/water or sorbitol/water), the T<inf>g</inf> values of all films were dramatically decreased to -50 °C for glycerol/water plasticized films and down to 0 °C for sorbitol/water plasticized films. The reasonable flexible films could be obtained by the use of either glycerol/water or sorbitol/water as couple plasticizers. - 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, Development of hydroxyethylacryl chitosan/alginate hydrogel films for biomedical application(2014-12-01); Yamaguchi, MasayukiNovel hydrogel films composed of hydroxyethylacryl chitosan (HC) and sodium alginate (SA) were prepared for biomedical application by using calcium chloride (CaCl<inf>2</inf>) as a nontoxic ionic crosslinker to form a semi-interpenetrating polymer network (semi-IPN). HC was successfully prepared by following a Michael addition reaction of chitosan (CS) and hydroxyethylacrylate completely dissolved in distilled water at 70 °C. The distribution pattern of Ca<sup>2+</sup> ions were well-dispersed within the hydrogel films examined by scanning electron microscope-energy dispersive spectrometry (SEM-EDS), implying uniformity of crosslinking. The swelling behavior of the hydrogel films in distilled water, simulated gastric fluid (SGF, pH = 1.2) and phosphate buffer solution (PBS, pH = 7.4) were investigated. The equilibrium swelling degree of the hydrogel films in distilled water increased with a decreas of either the SA content or the concentration of CaCl<inf>2</inf>. The hydrogel films showed pH-dependent behavior in that the shapes of the hydrogel films were stable in SGF while they degraded in PBS. The tensile strength and elongation of the hydrogel films reached 12.1 MPa and 162%, respectively, which presented reasonable mechanical properties during use and enough flexibility to follow skin movement. Cell viability of the hydrogels was measured using a methylthiazol tetrazolium (MTT) assay. The results indicated that the hydrogel films are not cytotoxic. - 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, 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dual pH/thermal-dependent coloring polymeric dye through Mannich reaction of chitosan: Synthesis and characterization(2019-11-01)