Low-pressure Spray Pyrolysis
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Low-pressure spray pyrolysis (LPSP) has been developed by generating micrometer-sized droplets under low-pressure environment. Unlike the conventional spray pyrolysis (CSP), a variety of nanoparticles, ranging from metals, metal oxides, to composite materials can be directly formed in the LPSP process, which was considered to follow a one-droplet-to-multiple-particles (ODMP) principle. The low-pressure is the direct driving force for the formation of nanoparticles. Inside the LPSP process, the micrometer-sized droplets are assumed to undergo rapid solvent evaporation upon entering the low-pressure environment that induces a fast nucleation rate to form primary nanocrystals. The aggregation of these nanocrystals is limited due to very short residence time under low-pressure conditions. In addition, the gas evolution due to thermal reactions and pressures inside the droplets/dried particles caused by high drying rates, are considered to be the main reasons for the fragmentation of primary nanocrystals into final nanoparticles.
KeywordsAgglomeration Brownian motion Evaporative cooling Fragmentation Nucleation
- 1.K. Okuyama, I. W. Lenggoro: Preparation of nanoparticles via spray route, Chem. Eng. Sci. 58 (3–6), 537–547 (2003).Google Scholar
- 3.W.-N. Wang, I. W. Lenggoro, K. Okuyama: Nanoparticle Preparation by Spray Route. In Encyclopedia of Nanoscience and Nanotechnology, 2nd ed.; Nalwa, H. S., Ed. American Scientific Publishers: Stevenson Ranch (in press).Google Scholar
- 4.T. T. Kodas, M. Hampdent-Smith: Aerosol Processing of Materials. Wiley-VCH: New York (1999).Google Scholar
- 10.W.-N. Wang: Synthesis of Nanoparticles via Spray Route under Low Pressure Conditions. Doctoral Dissertation, Hiroshima University, Higashi Hiroshima (2006).Google Scholar