Coated polystyrene particles as templates for ordered macroporous silica structures with controlled wall thickness

Abstract

Polystyrene (PS) colloidal particles have been used as templates to produce ordered macroporous silica structures. The silica films were deposited from ethanol solution containing acidic water and tetraethyl orthosilicate. The silica-coated PS spheres were characterized using transmission electron microscopy, and the film thickness determined by scanning electron microscopy and calculated from the relative weight of silica remaining after calcination. We found that the thickness of the silica film increased rapidly with time and reached a maximum that varied from 40 to 15 nm at pH 1.5 and 3, respectively. The data could be fitted to a simple first-order equation and the reaction rate and maximum thickness were related to the hydrolysis and condensation rate, respectively. Ordered macroporous structures were formed by centrifuging silica-coated PS spheres. Calcination of the close-packed spheres yielded a continuous silica matrix consisting of a threedimensional well-ordered network of monodisperse pores.

Mesopore-free silica shell with nanometer-scale thickness-controllable on cationic polystyrene core

“…Further, they used silica nanoparticles (as the silica source), which affected the inhomogeneous shell thickness, the surface roughness, and the existence of porous structures in the final product. Other methods based on the same strategy are reported by Chen et al [24] and Hotta et al [25]. Particles about 300 nm in size were effectively produced; unfortunately, the process was conducted in the very low pH condition (pH < 4), which can be a problem for practical applications.…”

Processing Routes to Macroporous Ceramics: A Review

“…87,92,110 The long periods required for complete pyrolysis of the organic component and the extensive amount of gaseous by-products generated during this process are the main disadvantages of using organic materials as sacrificial phase. Figure 6 shows a typical heat treatment employed for removing the organic material.…”

Agglomeration-free core-shell polystyrene/silica particles preparation using an electrospray method and additive-free cationic polystyrene core

“…Another process was reported by Hotta et. al [6]. However, they employed acid condition (pHo4) to control the component charge, which caused difficulty in handling process.…”