Thesis (D.Eng.)-- Chulalongkorn University, 2010

In this work, particulate composites of ZnO and carbon nanoparticles were synthesized by single-step gas phase reaction. Glycerol and ferrocene were used as carbon and iron sources for formation of the carbon nanoparticles, while Zn powder was employed as Zn source for the formation of ZnO. Isolated synthesis of carbon nanoparticles and ZnO particles was separately studied for investigating experimental parameters which affected the formation of each constituent of ZnO/CNT composite. The carbon nanoparticles, especially MWCNTs, were synthesized by chemical vapor deposition by manipulating N2 flow rate, synthesizing temperature and glycerol to ferrocene molar ratio. To understand the formation of the CNTs, synthesis of SWCNTs by laser ablation was also investigated by controlling laser intensity and synthesizing temperature. While, the ZnO nanoparticles were synthesized by oxidation of pure Zn by adjusting N2 flow rate, synthesizing temperature and O2 flow rate. The composites were then investigated under designated conditions with respect to data of previous investigation. The study of thermodynamics exhibited unavoidable oxidation of C and Fe over wide ranges of the synthesizing temperature. The synthesizing temperature was found to be a major parameter for the synthesis of the ZnO/CNT composites. Based on the experimental results, the ZnO/MWCNT composites could be synthesized under the condition of the N2 flow rate, O2 flow rate and synthesizing temperature of 500 mL/min, 100 mL/min and 800 ºC, respectively.