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Your search keyword '"Tanthapanichakoon, Wiwut"' showing total 59 results
Start Over Author "Tanthapanichakoon, Wiwut" Publisher elsevier bv
59 results on '"Tanthapanichakoon, Wiwut"'

4. Preparation of zinc coated PMMA using solid precursor by gliding arc discharge

Author

Ua-Amnueyc, Warit, Ua-Amnueychai, Warit, Kodama, Satoshi, TANTHAPANICHAKOON, WI, Tanthapanichakoon, Wiwut, and SEKIGUCHI, HIDETOSHI

Subjects
chemistry.chemical_classification, Materials science, General Chemical Engineering, chemistry.chemical_element, General Chemistry, Polymer, Zinc, engineering.material, Poly(methyl methacrylate), Industrial and Manufacturing Engineering, Electric arc, Coating, chemistry, visual_art, Electrode, engineering, visual_art.visual_art_medium, Environmental Chemistry, Particle, Composite material, Layer (electronics)
Abstract

A novel gliding arc discharge method using zinc particle as a solid precursor was used to coat poly methyl methacrylate (PMMA) particles to provide an adjustable electrical conductivity. An AC voltage of 4.5 kV was applied to the electrodes and 2 L min −1 of argon gas was injected to generate the gliding arc discharge. By using a combination of spouted bed condition and gliding arc discharge, a rapid coating performance was achieved. After 5 min of coating process, PMMA particles were observed to be covered by a fine zinc layer. The amount of coating increased at the beginning of the process and became relatively constant after 20 min. The amount of zinc coating was found to be approximately 10 mg/1 g of PMMA particle at a coating time of 10 min and 0.10 zinc/PMMA mass ratio in the bed. The percentage of zinc surface coverage was calculated to be 60% with a thickness of 140 nm. The coated samples exhibited electrical conductivity, approximately 3.7 × 10 −1 S m −1 at zinc/PMMA mass ratio of 0.15 with a thickness of 195 nm and a surface coverage of 75%. The amount of zinc coating showed a proportional relationship with both coating duration and zinc/PMMA mass ratio in the bed. The increase in the amount of zinc coating resulted in an increase of coating thickness, which further resulted in an increasing electrical conductivity of the coated polymer. The proposed method shows a promising potential for particle coating process.

Published
2015
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5. Development of encapsulation technique for curcumin loaded O/W emulsion using chitosan based cryotropic gelation

Author

Sowasod, Nataporn, Nakagawa, Kyuya, TANTHAPANICHAKOON, WI, Tanthapanichakoon, Wiwut, and Charinpanitkul, Tawatchai

Subjects
chemistry.chemical_classification, Materials science, Chromatography, Aqueous solution, Bioengineering, Polymer, Controlled release, Biomaterials, Chitosan, Colloid, chemistry.chemical_compound, chemistry, Chemical engineering, Mechanics of Materials, Emulsion, medicine, Curcumin, Swelling, medicine.symptom
Abstract

Cryogel based encapsulation of curcumin, an herbal extract, was successfully carried out with a ternary system of colloidal chitosan, κ-carrageenan, and carboxymethylcellulose sodium salt. The effects of chitosan concentration, κ-carrageenan/CMC ratio of the polymer suspension and molecular weight of chitosan on the sol–gel formation were investigated. The effects of cooling rate during freeze-drying and oil phase composition on the encapsulation yield and the release behavior of curcumin from the hydrogel were determined. And so were the effects of pH of the phosphate-buffered media and oil phase composition on the swelling of the specimens. The microstructure of the resulting specimens revealed core-shell nanoparticles (i.e. oil droplet for core and cryogel membrane for shell) entrapped in the cryogel matrix. The encapsulation yield for two types of suspensions was in a range of 83.9 to 99.6% when a high-MW chitosan was used. Controlled release of the encapsulated curcumin in an aqueous system could be maintained for 4 days, and the releasable amount of curcumin was in a range of 41.1 to 59.9%. The encapsulation yield as well as the released pattern and releasable amount of curcumin were significantly influenced by the cooling protocol used during freezing. Irrespective of the introduced oil phase composition, controlled release of curcumin was achievable when the cooling rate was sufficiently high at − 2.0 °C/min and, interestingly, either a burst release or a first order release could simply be achieved by changing the freezing condition.

Published
2012
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6. Adsorption and Ozonation Kinetic Model for Phenolic Wastewater Treatment

Author

Swasdisevi Thanit, Tongprem Pornsiri, Charinpanitkul Tawatchai, Tanthapanichakoon Wiwut, and Wongsarivej Pratarn

Subjects
Environmental Engineering, Aqueous solution, Ozone, Chromatography, General Chemical Engineering, Langmuir adsorption model, General Chemistry, Biochemistry, symbols.namesake, chemistry.chemical_compound, Adsorption, Wastewater, chemistry, Fluidized bed, symbols, medicine, Phenol, Activated carbon, medicine.drug, Nuclear chemistry
Abstract

A three phase fluidized bed reactor was used to investigate the combined effect of adsorption and oxidation for phenolic wastewater treatment. Aqueous solutions containing 10 mg·L −1 of phenol and ozone were continuously fed co-currently as upward flow into the reactor at constant flow rate of 2 and 1 L·min −1 , respectively. The phenolic treatment results in seven cases were compared: (a) O 3 only, (b) fresh granular activated carbon (GAC), (c) 1st reused GAC, (d) 2nd reused GAC, (e) fresh GAC enhanced with O 3 , (f) 1st reused GAC enhanced with O 3 , and (g) 2nd reused GAC enhanced with O 3 . The phenolic wastewater was re-circulated through the reactor and its concentration was measured with respect to time. The experimental results revealed that the phenolic degradation using GAC enhanced with O 3 provided the best result. The effect of adsorption by activated carbon was stronger than the effect of oxidation by ozone. Fresh GAC could adsorb phenol better than reused GAC. All cases of adsorption on GAC followed the Langmuir isotherm and displayed pseudo second order adsorption kinetics. Finally, a differential equation for the fluidized bed reactor model was used to describe the phenol concentration with respect to time for GAC enhanced with O 3 . The calculated results agree reasonably well with the experimental results.

Published
2011
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7. Effect of zinc precursor on thermal and light emission properties of ZnO nanoparticles embedded in polyimide films

Author

Somwangthanaroj, A., Suwanchatchai, K., Ando, S., TANTHAPANICHAKOON, WI, and Tanthapanichakoon, Wiwut

Subjects
Nanocomposite, Materials science, Thermal decomposition, Inorganic chemistry, chemistry.chemical_element, Nanoparticle, Zinc, Condensed Matter Physics, Crystallinity, chemistry, General Materials Science, Light emission, Thin film, Polyimide, Nuclear chemistry
Abstract

The novel nanocomposites consisting of fluorinated polyimide (PI) films and zinc oxide (ZnO) nanoparticles, from which green light emission was observed, have successfully been prepared. The embedded ZnO nanoparticles in PI films were prepared by adding two separate zinc compounds in poly(amic acid) (PAA) solution followed by thermal curing to convert PAA to PI. The added zinc hexafluoroacetylacetonate dihydrate (Zn(hfac)) and zinc nitrate hexahydrate (Zn(NO3)2), were converted by thermal decomposition to semicrystalline ZnO nanoparticles, which was confirmed by XRD technique. The green light emission of the nanocomposite films irradiated by UV light was caused by the intrinsic defects in ZnO crystallites. The PI films embedded with ZnO from Zn(NO3)2 emitted much higher fluorescent intensity than their counterparts from Zn(hfac). In addition, the Zn(hfac)/PI film was thermally more stable than the Zn(NO3)2/PI one. From TEM images, the size of ZnO nanoparticles in PI films derived from 28 mol% Zn(hfac) was much larger than those from 59 mol% Zn(NO3)2.

Published
2009
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8. Effect of pH of fine silica suspension and central rod diameter on the cut size of an electrical hydrocyclone with and without underflow

Author

Hideto Yoshida, Wongsarivej Pratarn, Tanthapanichakoon Wiwut, and Fukui Kunihiro

Subjects
Hydrocyclone, Arithmetic underflow, Silica suspension, Chemistry, Correlation analysis, Zeta potential, Slurry, Mineralogy, Filtration and Separation, Composite material, Suspension (vehicle), Analytical Chemistry, Volumetric flow rate
Abstract

A 20 mm-diameter electrical hydrocyclone was developed and tested. The presence of the underflow results in a smaller d50 than the absence of the underflow. Additionally, the higher the feed flow rate, the smaller d50. Effect of central rod diameter and initial pH of suspension on the separation cut size was examined with and without underflows. The d50 decreases with the increase of central rod diameter and initial pH values in both with and without the underflow. The zeta potential of particles increases proportionally with the initial pH of suspension. The electrical potential exhibits a stronger effect when the suspension has a higher pH. The d50 becomes smallest under largest central rod diameter, highest pH and longest slurry collecting box condition operates with the positive electrical potential at side wall in the presence of the underflow. Based on the experimental data, general semi-empirical correlations were proposed and the effect of each parameter on d50 was examined.

Published
2008
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