Preparation Of Monodispersed Colloidal Silica Particals And Fabrication Of Silica Colloid Crystal

In recent years, colloidal crystal technology has attracted an increasing interest due to its various applications in the fields such as ceramics, optoeletronic devices and photonic band-gap crystals and so on. Molecular sieves with hierarchical porous structure can be prepared by using the colloidal crystal template technology. This kind of materials is quite beneficial for large-molecule separations and substance transfers. To control the colloidal particle size and its monodispersity is the key in developing two- or three-dimensional self-assembled structures where individual colloidal particle plays the role of building blocks - artificial atoms. Therefore, relatively simple and reproducible approaches for the synthesis of colloidal particles with controllable size are of great fundamental and technological interest. So far, only silica and some polymer colloids can be routinely prepared with the narrow size distribution required for forming monolithic high-quality colloidal crystals. In the past decades, some nucleation mechanism of monodisperse silica colloidal particles formation were put forward. Unfortunately, to this day, none of the available nucleation mechanisms is able to explain all the experimental facts. In this contribution, based on the plenty of the present literatures and combining with the feature of our laboratory, we mainly carried out the following work and got some useful experimental results:I Controling different reaction experimental condition (the concentration of tetraethylorthosilicate, water, ammonia and the temperature), highly monodispersed silica colloidal particles with diameter range from 30nm to 800nm were synthesized freely. When the concentration of ammonia and tetraethylorthosilicate was increased, the particle sizes increased; When the reaction temperature was increased, the particle sizes decreased; when the amount of water was increasd, the particle sizes increased first, after a maximum value, then the particle sizes decreased. The formation mechanisms of the resultant silica particles under different reaction conditions were...