Thermodynamic and kinetics of adsorption of basic dyes (methylene blue and basic blue 3) on wood charcoal activated at 800 °C, prepared from Bombax Cieba (M78D) was investigated. Equilibrium data was obtained using batch method at temperatures of 10 °C to 50 °C. It was found that adsorption increase with increase in temperature. The Langmuir isotherm model describe the equilibrium of adsorption. Thermodynamic parameters such as ΔS°, ΔH° and ΔG° were calculated. From the values of ΔH° and ΔG°, it was concluded that the adsorption process is endothermic and spontaneous in nature. To determine kinetics parameter Lagergren equation was applied, and it was found that the reaction proceed through first order kinetic mechanism.

The aim of this paper was to investigate the effects of cross-linked reaction on physicochemical properties of chitosan film by using genipin as cross-linker agent. Series of chitosan film samples with different amount concentration of genipin loaded (0-3 wt %) were prepared and characterized. The physicochemical properties of films were evaluated by Fourier Transform Infra-red (FTIR), UV-vis spectroscopy, Oxygen Transmission Rate (OTR), Scanning Electron Microscopy (SEM), water vapour and tensile test. The cross-linking reaction had affected on colour changing of chitosan film samples from light yellow to dark blue in line with the increasing of genipin concentration. Thus, UV-vis spectroscopy on the cross-linked samples showed the absorbance value at 600 nm wavelength due to genipin content. FTIR observation on cross-linked film samples showed no characteristic of –OCH3 peak from genipin at 1444 cm-1 which resulted by new covalent bonding occurred between chitosan and genipin. Cross-linking also had increased the oxygen barrier and reduced the water vapor rate through the film. Chitosan film sample with addition of 1 wt% genipin achieved the highest tensile stress average at 49.46 MPa compared to other samples while percent of elongation at break reduced with the increasing of genipin concentration loaded

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The purpose of this study was to prepare biphasic granules containing gypsum and carbonated apatite at low temperatures. The biphasic granules were prepared using dissolution-precipitation technique at three different temperatures 30°C, 40°C and 50°C. Characterization of the biphasic granules was determined by multiple analytical methods such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infra-red (FTIR), and CHN Analysis. The obtained granules were determined by XRD as biphasic granules containing bone apatite and gypsum. The cross-section of biphasic granules was observed by SEM. The formed bone apatite was identified as B-Type carbonated apatite using FTIR The carbonate content in biphasic granules fabricated at 30°C, 40°C and 50°C were recorded by CHN analysis as 5.0 wt%, 6.1 wt% and 6.25 wt%, respectively.

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