Topological Control of Polystyrene-Silica Core-Shell Microspheres

Publication date: Available online 5 October 2018Source: Colloids and Surfaces A: Physicochemical and Engineering AspectsAuthor(s): Zane A. Grady, Alexandria Z. Arthur, Christopher J. WohlAbstractControllable surface morphology is requisite across a gamut of processes, industries, and applications. The surface morphology of silica-coated polystyrene microspheres was controllably modified to enable generation of both smooth and bumpy, or raspberry-like, surfaces. Although smooth and raspberry-like silica shells on polystyrene templates have been demonstrated extensively, the method described here used readily available materials to produce radical changes in surface morphology from a single polystyrene template coated in silica through a facile sol-gel reaction processes. Silica shells were deposited via a sol-gel process (using tetraethyl orthosilicate as the silica precursor) onto 1 to 2 μm diameter anionic polystyrene spheres, fabricated by emulsifier-free polymerization. By varying the concentration of silica precursor and ammonium hydroxide catalyst and altering the electrostatic surface interactions via addition of a cationic polymeric brush, an array of surface topologies was generated. Incremented addition of the ammonium hydroxide base catalyst and sol-gel precursors generated smooth silica shells, whereas identical one-pot reactions led to raspberry-like shells. This modification of sol-gel deposition on large polystyrene cores via means of reactant addition offers ...
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Category: Chemistry Source Type: research
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