Siriphannon, Punnama
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Preferred name
Siriphannon, Punnama
Alternative Name
Siriphannon, P.
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Email
punnama.si@kmitl.ac.th
34 results
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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, Facile Preparation of Montmorillonite/Crosslinked Chitosan Containing Potassium Nitrate Nanocomposites as Eco-Friendly Slow Release Fertilizers(2023-08-01); Montmorillonite/tripolyphosphate crosslinked chitosan containing potassium nitrate nanocomposites (MMT/CS-KNO3-TPP) were synthesized by facile incipient wetness impregnation method. The MMT was impregnated stepwise with a mixture of protonated chitosan and KNO<inf>3</inf>, followed by a TPP solution to ionically crosslink with chitosan, resulting in MMT/CS-KNO3-TPP nanocomposites. The initial quantity of KNO<inf>3</inf> to MMT was varied from 0 to 10, 20, and 30 wt%, and the TPP crosslinker was varied according to TPP:chitosan weight ratios of 0:5, 1:5, and 3:5. The resultant MMT/CS-KNO3-TPP nanocomposites composed of the K<sup>+</sup> and NO<inf>3</inf><sup>−</sup> ions embedded in crosslinked chitosan which intercalated in the MMT basal spacing and covered on MMT external surface. The structure of these nanocomposites could effectively slow the K<sup>+</sup> and NO<inf>3</inf><sup>−</sup> releases, with the 72- hours cumulative released values (%R) ranging from 20–34% for K<sup>+</sup> to 0.4–1.0% for NO<inf>3</inf><sup>−</sup>. The MMT/CS-KNO3-TPP nanocomposites with higher TPP concentration could extend the K<sup>+</sup> and NO<inf>3</inf><sup>−</sup> release times. Total K<sup>+</sup> release times were predicted to be in the range of 128–204 days. The presence of MMT/CS-KNO3-TPP nanocomposites in RD43 rice cultivation could promote the growth of RD43 seedlings and roots. Furthermore, the TPP crosslinked chitosan showed physical changes in distilled water, indicating its potential as a long-term nitrogen (N) and phosphorus (P) source for plant nutrients. - 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, Polyelectrolyte-Assisted Immobilization of Oil-Based Nanocapsules on Cotton Fabric(2016-01-01) - 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Soft solution growth of magnetite-maghemite nanocrystals in crosslinked chitosan templates and their superparamagnetic properties(2022-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Sphere-like and flake-like ZnO immobilized on pineapple leaf fibers as easy-to-recover photocatalyst for the degradation of congo red(2021-04-01); Smith, Siwaporn MeejooThis work reports immobilization of ZnO photocatalyst on very fine pineapple leaf fiber (PALFs) by a by polyelectrolyte coating method, for the removal of colored pollutants from water stream, allowing for simple recovery after use. It also emphasizes on the effect of defect structure containing in ZnO of hierarchical sphere-like and flake-like morphologies on the color removal performance. The photocatalytic activity of ZnO/PALFs for degradation of congo red (CR) dye was examined under static (dark) and UV/visible irradiation conditions, and effective color removal (>95 %) was achieved, as the results of adsorption and photo-oxidation processes. Results from photoluminescence and X-ray photoelectron spectroscopy suggested that the sphere-like ZnO, bearing zinc vacancies (VZn), zinc interstitials (Zni), singly ionized oxygen vacancies (Vo+), and oxygen vacancies (Vo), has superior photocatalytic activity up to 3.6 times compared to that of flake-like ZnO. With the recyclability up to 3 cycles (>84 % color removal efficiencies), the ZnO immobilized on PALFs have shown a great promise as an easy-to-recover photocatalyst for the removal of colored pollutants in wastewater treatment processes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Facile preparation of copper impregnated aluminum pillared montmorillonite: nanoclays for wastewater treatment(2016-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Chitosan intercalated montmorillonite: Preparation, characterization and cationic dye adsorption(2009-01-01); Chitosan intercalated montmorillonite (Chi-MMT) was prepared by dispersing sodium montmorillonite (Na<sup>+</sup>-MMT) into chitosan solution at 60 °C for 24 h. The Chi-MMT was characterized by XRD, XRF and FT-IR. The intercalation was accomplished via the ion-exchange of Na<sup>+</sup> ions with -NH<inf>3</inf><sup>+</sup> of chitosan, resulting in the expansion of d<inf>001</inf> from 1.42 nm of Na<sup>+</sup>-MMT to 2.21 nm of Chi-MMT. The chitosan content in the Chi-MMT measured by TGA was about 17 mass%. The adsorption capacity of Chi-MMT was investigated in comparison with the starting Na<sup>+</sup>-MMT and chitosan using three different cationic dyes, i.e. basic blue 9 (BB9), basic blue 66 (BB66) and basic yellow 1 (BY1). The Chi-MMT showed the highest adsorption capacity in the range of 46-49 mg/g when the initial dye concentration was 500 mg/L, being equivalent to 92-99 wt.% of dye removal. The adsorption capacities of Chi-MMT for all basic dyes increased with an increase of initial dye concentration. An increase of adsorption capability of Chi-MMT was attributed to the existence of intercalate-chitosan. It could enlarge the pore structure of Chi-MMT, facilitating the penetration of macromolecular dyes, and also electrostatically interact with the applied dyes. These results indicated the competency of Chi-MMT adsorbent for basic dye adsorption. © 2008 Elsevier B.V. All rights reserved. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Bioactive alginate/carrageenan/calcium silicate porous scaffolds for bone tissue engineering(2021-03-01); Porous bioactive alginate/carrageenan/calcium silicate scaffolds for bone tissue engineering were fabricated. The scaffolds were prepared by dispersing the synthesized calcium silicate in an aqueous solution of alginate and carrageenan at 90 °C. The scaffolds were shaped by freeze-drying and further crosslinked by 0.5, 1.0 and 1.5 M CaCl<inf>2</inf> for 60 and 120 min. The scaffolds crosslinked by 1.5 M CaCl<inf>2</inf> for 120 min achieved the highest in vitro dimension stability. The formation of hydroxyapatite crystals was observed on the scaffolds surface after soaking in simulated body fluid (SBF) at 37 °C for 7–28 days, indicating in vitro bioactivity of the scaffolds. The presence of calcium silicate could enhance not only the bioactivity, but also the mechanical properties of the scaffolds comparable to the cancellous bone. Moreover, the dimension and mechanical properties of the wet scaffolds could recover to the original after four cycles of mechanical testing at 50 % strain. The scaffolds were nontoxic to human living cells, in which the in vitro drug release behavior of the scaffold using diclofenac as a model drug was suitable for the treatment of acute inflammation after surgery. Therefore, these scaffolds were considered to be the candidate materials for bone replacement.