Sol-gel silica, synonymous today with St�ber silica, has received increased interest because of its many applications. Particles prepared through a modified St�ber procedure were found to sediment in layers over time. Each layer had monodisperse particles capable of packing in 2D zig-zag and hexagonal arrays. In order to investigate the colloidal stability, the stratified silica was monitored over a longer period of time. Techniques such as dynamic light scattering, DLS, transmission electron microscopy, TEM, and asymmetric flow field flow fractionation (AF4) were used to evaluate the particle size. AF4 proved to be a reliable and high-resolution tool to fractionate the stratified colloid. Upon storage in the initial, slightly basic condition, particles changed their morphology, yielding novel mesoporous structures as a result of etching. This work was supported by the Grants DMR-1005707 from the National Science Foundation.

Preparation and characterization of stratified colloidal silica

246th National Meeting (2013)

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