Sakdiphon Thiansem

Cost Effective Natural Adsorbent for Fluoride Removal

In this study, the uptake of fluoride by raw diatomite and diatomite activated by heat treatment was investigated. Influential parameters such as contact time, pH and adsorption isotherm were also studied. The results showed that the diatomite heated to 500 oC performed better than other heat treatment products and the equilibration time needed for fluoride removal by the adsorbents was reached at 60 min. Results revealed that the capacity of the adsorbents for removing fluoride is independent of the pH when the pH is higher than 4. The adsorption isotherm of the 500 oC treated diatomite showed its Langmuir behavior. The maximum adsorption capacity of raw diatomite and 500 oC calcinated diatomite are 2.253 and 4.162 mg/g, respectively. Based on the results it can be concluded that the diatomite appears to be an economical and environmentally friendly material for defluoridation of water.

Effect of sodium dodecylbenzene sulfonate on the dispersion stability of ceramic glaze suspension

Sodium dodecylbenzene sulfonate (SDBS) was used to render the stability of ceramic glaze dispersion which is composed of limestone, feldspar, quartz, kaolin and ferric oxide. The measured zeta potential showed negative values for the systems in deionized water and 0.001 M MgCl2 media at pH above 2, but a positive value was observed in 0.1M MgCl2 at pH higher than 6.7. Adsorption of SDBS in aqueous suspensions of ceramic glaze in deionized water and in 0.001 M MgCl2, within the concentration range studied, followed both the Langmuir and Freundlich isotherms, but the Freundlich isotherm was more favored. Adsorption of SDBS in 0.1M MgCl2 corresponded to the Freundlich isotherm. From dispersion stability investigation, SDBS could render the suspension in deionized water and in 0.001 mM MgCl2 more than in 0.1 mM MgCl2.

The Effect of Alumina (Al2O3) on the Characteristics of Sintered Mullite-Cordierite Ceramics Synthesized with Kaolin from Naratiwas of Thailand

Mullite-cordierite ceramics was prepared by the three composition of talc, kaolin (kaolin from Naratiwas in Thailand) (NT) and alumina. The different amounts of alumina (5, 10, 15 and 20 wt%) were added to produce various mullite-cordierite alumina mixtures which are denoted as NA, NB, NC and ND, respectively. The mixtures were pressed into rectangular shapes by hydraulic press with the pressure of 150 kg/cm2 then sintered at temperature of 1300 °C and 1350 °C for 2 hours. The morphology of the synthesized mullite-cordierite samples were characterized by x-ray diffraction spectroscopy (XRD), and physical-mechanical properties were investigated. Mullite-cordierite was successfully synthesized. The XRD result was represented phases of mullite and cordierite. The NA samples sintered at temperature of 1300 °C indicated the best physical-mechanical properties including bulk density (2.23 g/cm3), flexural strength (44.4 MPa) and thermal expansion coefficients (5.00x10-6). The other NA samples sintered at temperature of 1350 °C exhibited the bulk density, flexural strength and thermal expansion coefficients are 2.21 g/cm3, 47.8 MPa and 4.99 x10-6, respectively. The thermal expansion coefficient of the NT sintered samples have been plotted the length change relative to measuring temperature ranging of 30-1200 °C. The suitable condition of the synthesized mullite-cordierite ceramics is finally obtained the NA samples with 5 percent weight of alumina composition sintered at the temperature of 1350 °C.

Effect of Hydroxyapatite Bioceramic Bodies on Subcutaneous Soft Tissue Reaction of Laboratory Rats

Hydroxyapatite (HA) is widely used in bioceramic materials for bone grafting. HA scaffolds were synthesized using solid-state reaction method. Scaffolds were prepared by milling the elements of CaCO3 and NH4H2PO4 powders. The obtained powder was pressed with uniaxial pressing into a disc shape with the dimension of 4 mm in thickness and 16.5 mm in diameter under pressures 3 MPa and then sintering the samples at difference temperatures from 1100°C to 1300°C for 3 hours. This research aimed to produce phase HA scaffolds in order to find out the effects of sintering temperature on phase contents, density, porosity, hardness and bending strength, and to use optimized condition samples study with laboratory rats’ soft tissue to evaluate the soft tissue response to the samples. Thirty-two healthy in adults’ on non-gender-specific of Wistar rats were used in this study. Optimized, sintered samples were cut and lathed into a cylindrical shape. Sixty-four samples of optimized condition were implanted and left in subcutaneous tissue for 3, 7, 14, 21, 30, 45, 90 and 180 days. XRD, XRF, Archimedes technique, Vickers hardness and bending strength, as well as light microscopy, were used for analysis. The results of optimized condition have shown the bodies of sintered sample at 1300 °C for 3 hours had the highest content of 91.02 % HA phase, and the remaining phases of 4.51 % b-TCP and 4.47 % CaO, its bulk density and strength increased with increasing temperature, the highest bulk density of 2.006 ± 0.033 g/cm3, hardness of 30.02 ± 3.23 HV, bending strength of 9.07 ± 1.15 MPa. Sample reactions to soft tissues at 180 days were mild inflammatory cells, an absence of cellular infiltration, a presence of calcification, and absence of displacement of ceramic components into surrounding host tissue. Our results concluded that the samples were nontoxic to subcutaneous tissue and biocompatibility

Absorbable suture made from rice starch

The main objective of this work is to make an absorbable monofilament suture from Thai rice starch. The improvement of the mechanical properties of Thai rice starch polymer films were achieved by addition of small amount of gelatin, carboxymethylcellulose (CMC) and carbon nanopowders. The carbon nanopowders were produced from coconut shell in our laboratory room by milling method. The incorporation of carbon nanopowders with a high aspect ratio and/or an extremely large surface area into Thai rice starch polymer films improves their mechanical performances significantly. Additionally, the black color from carbon nanopowder is easily visualized in tissue during surgery. The manufacturing processes are very simple by blending of the raw materials in hot water and then dry heating in electric oven. The final product was characterized of microstructures and mechanical properties. The resulting Thai rice starch-carbon nanocomposites possess several advantages for manufacture of sutures: 1. high water resistance that can be uses in the human body. 2. high mechanical strength that appropriate to manufacture of sutures. 3. biocompatibility and bioabsorbable. 4. low cost. 5. Eco-friendly green nanocomposites. However, the method of size designation of sutures fibers and needle attachment are the problem which restricts our suture in really applications. The investigation of knowledge and simple technology of manufacture of suture and needle attachment will be performed.

Fabrication and Characterization of Novel Bone Void Filler Made from Hydroxyapatite-Rice Starch Composite

The aim of this study is fabricated bone void filler (BVF) made from hydroxyapatite (HA)-rice starch (RS) composite. We provided HA derived from cockle shells and RS derived from Thai rice starch. BVF was prepared by adding the pore former method to mimic the pore structure of bones. The samples were heated at 1250°C for 3 hours. Then, the composites were prepared by dipping and coating surface of the samples with RS gel. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed that bovine bone and BVF are made of HA phase. Film of RS gel coated on surface of samples indicated that BVF without toxicity and would increased the proliferation of bone cells. Moreover, it was found that BVF after coated RS gel had water absorption value higher than before coated as 25% that exhibited a good capacity of regeneration bone.

Utilization of leonardite and coal bottom ash for production of ceramic floor tiles

The aim of this research was to exploit leonardite and coal bottom ash (CBA), which are waste products from coal power plants, for investigating their potential as raw materials in the production of ceramic floor tiles. The developments of ceramic body were mixed with traditional raw materials. Different proportions of ceramic materials were studied in order to explore the proper composition with a variety of wastes containing leonardite and coal bottom ash from 20% up to 80%. Unglazed tiles were produced by shaping through dry pressing and single firing. The physical, chemical, and mechanical properties of the samples were investigated. The total waste (CBA and leonardite) contained in the production was close to 42.8%, and it presented properties that are adequate for it to be classified in groups within the ISO 13006 standard, and yielded the highest flexural strength which enabled the obtained ceramic floor tile bodies to satisfy the requirement to be classified in group BIIa. The chemical resistances of the products were classified in the category UA group which passed the minimum requirement for classification as chemical attack, set by standard EN 14411.

Analytical Study of Ancient Pottery from the Archaeological Site of Ban Bo Suak from Nan Province, Thailand

Ban Bo Suak pottery sherds were analyzed by using X-Ray Fluorescence, X-Ray Diffraction and Scanning Electron Microscope. The samples JQA.SH1, FQB.SH3, PQC.SH5 and NQD.SH7, showed that phase structure were quartz, tridymite and mullite phase. It was confirmed that sherds were fired at high temperature more than 1000 °C. As a result, they made the body and glaze compacted and turned into stoneware at high temperature. SEM images of surface showed the middle layers between glaze and body for JQA.SH1 and FQB.SH3. The decoration techniques were glazed and slip layer between bodies and glaze.

Preparation and Characterization of Clays from Different Areas in Ban Bo Suak, Nan Province, Thailand

The scientific process was used to explain characterization and physical properties of the clay sample close to the ancient Nan kiln site. These samples were obtained from JQA, FQB, PQC and NQD. X-ray diffraction (XRD) and X-ray fluorescence (XRF) technique were used to determine the chemical composition and phase transformation before and after fired at 800-1250 °C. XRF result was confirmed that all clay samples mainly contained SiO2 (>80 wt. %) XRD pattern indicated that quartz was the majority of phase in the all of them. High amount of Fe2O3 (>1.6 wt. %) was related to the red-brown tone color. The clay sample could be fired up to 1280 °C without wrapping behavior; it was found that FQB clay had the highest firing resistance due to the maximum quartz content.

Synthesis of Hydroxyapatite Powder from Mollusc Shell

Synthesis hydroxyapatite (HA) powders from mollusc shell with the solid solution reaction method. The process is a new method which makes the amount of HA powder in large quantities. The advantage of the solid state method which involves molar ratio of calcium and phosphorus through a thermal treatment and reaction time, caused by the diffusion of ions in the solid particles. HA is the only apatite present in the reaction products, apart from minute fractions of certain other calcium compounds. The final product is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fourier transform infrared (FTIR)