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Detailed Program
Paper Number : SY-P02
Time Frame : 12:00~13:30
Presentation Date : Thursday, 27, November
Session Name : Synthesis, Raw Materials & Advanced powder processing
Session Chair 1# : -
Session Chair 2# : -
Continuous Production of Monodisperse Silica Particles Using Tubular Reactor
Prof. Young-sang Cho
Korea Polytechnic University
The synthesis of monodisperse particles have been considered as important research topic in the field of colloid science and technology. Specifically, metal oxide particles with narrow size distribution have been studied for various applications such as building block materials of self-assembly, cosmetics, and chemical mechanical planarization. Usually, the synthesis of monodisperse particles has been carried out using laboratory-scale batch-type reactor to study the factors affecting the particle size and distribution. However, batch type reactors have drawback in that it is difficult to establish the scale-up conditions for the large-scale production of the particle suspension. Thus, it is essential to study the continuous production of monodisperse colloids using proper reaction system such as tubular reactor. In this study, monodisperse silica nanospheres were synthesized by tubular reactor for the continuous production of the particles. For sol-gel reaction, silica precursor such as TEOS (tetraethylorthosilicate) and ammonia/water mixture were separately fed to the T-mixer which connects two input flows of the reactants into one outlet tube composed of Teflon. The mixing of the reactants was performed using static mixer for the complete hydrolysis and condensation reaction of TEOS. For the size control of the particles, retention time of the reactants was adjusted by changing the length of the tubular reactor or feeding rate of the liquid materials. The reactant composition was also changed to study the effect of the particle size and distribution of the silica nanospheres. Fig. 1 contains the average size of the silica nanospheres as a function of production time. The size of the particle suspension was measured by light scattering method using ZETA PLUS apparatus and retention time was adjusted from 68 to 162 minutes for the tubular reactor with 7.5 m in length. As displayed in the graph in Fig. 1, the particle size fluctuates as a function of production time when the retention time was 68 minutes, which may not be enough for the completion of the reaction. Relatively uniform size of the particles was observed when the retention time becomes longer.
Acknowledgements : This research was financially supported by a grant by Ministry of Land, Infrastructure and Transport (MOLIT) of Korea government and Korea Agency for Infrastructure Technology Advancement (KAIA, 14CTAP-C078865).