Synthesis of non-agglomerated nanoparticles by an electrospray assisted chemical vapor deposition (ES-CVD) method

Abstract

Non-agglomerated spherical silicon, titanium and zirconium oxide nanoparticles were prepared using anelectrospray assisted chemical vapor deposition (ES-CVD) process. Metal alkoxides in conjunction with anelectrospray method were used to introduce charged precursors into a CVD reactor. The ions are producedduring evaporation o fthe charged droplets, and they probably act as seed nuclei (i.e., ion-induced nucleation)and/or, they are attached to the produced particles. The experimental results were compared with those obtainedusing a conventional evaporation CVD method. The particles generated using the conventional evaporationmethod were agglomerated to a considerable extent irregardless o fthe type o fparticle. Whereas, at the sameconditions, high concentrations o fnon-agglomerated nanoparticles having diameters in the range o f10 –40 nmwere obtained using the ES-CVD method. This appears to be due to the charging e:ects o fthe generatedparticles, that is, the electrostatic dispersion o funipolarly charged particles. The size o fthe non-agglomeratedparticles in the ES-CVD method was reduced as the results o fthe decease in the concentration o fprecursorsintroduced by electrospray.