JEO: Journal Articles

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https://hdl.handle.net/20.500.14437/123

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Browsing JEO: Journal Articles by Subject "Chemistry"

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    A Comparative Study of Absorption Capacity of Activated Carbons Prepared from Rice Straw, Rice Husk Shell and Sugarcane Bagasse by a Chemical Activation Method with H3PO4
    (Chulalongkorn University Printing House, 2008)
    Laowachirasuwan, Katsiri
    ;
    University of the Thai Chamber of Commerce. Journal Editorial Office
    In this research the activated carbons were prepared from rice straw, rice husk shelland sugarcane bagasse using a chemical activation method by impregnation with H3PO4at identical optimum conditions: activation temperature of 600 oC, activation agent toraw material ratio of 1:1 and activation time of 60 minutes. The derived activated carbonswere then analyzed for the composition by proximate analyses and the adsorption capacityof iodine and methylene blue. In addition, Freundlich adsorption isotherms of theadsorption capacity of iodine and methylene blue were investigated. The results showedthat the activated carbon obtained from rice straw yielded the highest iodine adsorption(Iodine number), 998 mg/g. The activated carbon obtained from rice husk shell showedthe highest methylene blue adsorption, 305 mg/g. When compared to the two commercialactivated carbons, the activated carbon obtained from rice straw had an iodine adsorptioncapacity close to the second commercial activated carbon, but less than the first one.While the methylene blue adsorption capacity of the activated carbon obtained fromthose three experimental materials had lower levels compared to the two commercialactivated carbons. However, the activated carbons obtained from rice straw, rice husk shelland sugarcane bagasse still showed the good qualities to use as activated carbon becauseall iodine numbers are more than 600 mg/g and the moisture contents (%) are less than8%, the standards considered by the TISI.900-2547.
      18  193
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    Fullerenes and Fullerene Derivatives in Properties and Potential Applications
    (Chulalongkorn University Printing House, 2008)
    Laowachirasuwan, Katsiri
    ;
    University of the Thai Chamber of Commerce. Journal Editorial Office
    After the discovery of Fullerenes, the 60-atom clusters and large carbon-cage molecules,the attention of scientists and materials scientists has been attracted by the synthesesof new materials based on the family of Fullerene molecules. Many properties ofFullerenes are new and unusual. With a better understanding of their chemical andphysical properties, the fabrication of new materials for advanced applications hasemerged as a challenging possibility. As we know that Fullerenes are easily modified,using organic chemistry and special synthetic techniques, into other molecular structures,this makes them remarkably versatile. The versatility of Fullerenes gives them enormousapplications. This paper will review on Fullerenes and Fullerene derivatives properties,what is interesting about these çnewé carbon materials and how their unique propertiescan be utilized in potential applications. Applications of Fullerenes and Fullerenederivatives in areas such as semiconductors, superconductors, polymer-like materials,catalysts have been reviewed. In the medical field, the potential applications ofFullerenes and Fullerene derivatives include diagnostic or therapeutic agents, inhibitionof HIV-P, powerful biological antioxidants, antibacterial activity, and DNA photocleavage.
      19  72
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    The Effect of Acidcbase Concentration on UV Absorption of Titania Prepared via Sol-Gel Synthesis
    (Chulalongkorn University Printing House, 2014)
    Sathitdetkunchorn, Wilasinee
    ;
    University of the Thai Chamber of Commerce. Journal Editorial Office
    The present study aimed to investigate the effect of various acids and pH towards the UV absorption of titania powder prepared by a sol-gel method. Hydrochloric acid HCl sulfuric acid H2S04 and nitric acid HN03 with various pH of 2 3 4 5 and 6 respectively were used as starting materials. The results revealed that the UV absorption of titania powder depends on acids and pH. The results also suggested that the titania powder prepared by HCl with pH 6 has maximum UV absorption with A = 1.98929.
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