Preparation of Silica‐Coated Polystyrene Hybrid Spherical Colloids

Abstract

Summary: A novel preparation method for stable PS/SiO2 core‐shell hybrid colloid was proposed. In this process, a positively charged PS colloid was first synthesized via surfactant‐free emulsion polymerization of styrene by using a cationic initiator, and the hydrolysis and condensation of tetraethoxysilane (TEOS) was then carried out in acidic aqueous ethanol medium in the presence of PS colloids. Silica layer was deposited onto the surface of PS particle via electrostatic interaction between positively charged PS colloids and negatively charged silica. No surface treatment and centrifugation/redispersion cycle process were needed. TEM, SEM, and zeta potential measurements indicated that silica layer was successfully coated onto the surfaces of PS colloids.

Synthesis of polystyrene/silica composite particles by soap-free emulsion polymerization using positively charged colloidal silica

“…In addition, the TGA curves shift to the right in the decomposition region when the silica content exceeds 10 wt%, because of the strong interaction between polystyrene and silica. Therefore, the composite particles are reinforced in terms of thermal stability by the adsorption of silica when the silica content is high [10]. …”

“…Silicacontaining hybrid polymer particles could embody various colors and have excellent physical reinforcement and thermal resistance by means of silica. Therefore they have been applied to thermal insulation, bioactive supports, paints, drug delivery, and composite materials [8][9][10]. These polymer/silica composite particles are generally produced by incorporation of colloidal silica at the beginning of heterogeneous polymerizations [11][12][13][14][15][16] such as emulsion, dispersion, and suspension polymerization.…”

“…On the other hand, utilizing the negative surface charge of silica particles, a positive surface charge is endowed to the polymer particles to maximize an electrostatic attraction between silica nanoparticles and polymer particles. A cationic initiator, azobisisobutyramidine dihydrochloride (AIBA), has been successfully used for the capsulation of negatively charged silica particles by dispersion [13,19] or emulsion polymerization [10]. When a neutral initiator, 2,2 -azobisisobutyronitrile (AIBN), is used instead, only a small amount of silica (negatively charged), ca.…”

A direct preparation of silica shell on polystyrene microspheres prepared by dispersion polymerization with polyvinylpyrrolidone

“…Utilizing the negative surface charge of silica particles, initiators which give positive charges to the polymer surface increase the incorporation of silica particles. 18,19 The use of oppositely charged initiator to silica enhances the adsorption efficiency up to 40 wt %. 20 Using basic comonomers such as 4-vinylpyridine 21 and 1-vinylimidazole, 22,23 the formation of hybrid particles is facilitated by an acid-base interaction.…”

Monodisperse micrometer-ranged poly(methyl methacrylate) hybrid particles coated with a uniform silica layer

“…[1][2][3][4] A sol-gel process has been commonly employed in the preparation of the hybrid composites since it can be carried out simply and rapidly at low temperatures and mild conditions. 5,6 By applying the sol-gel process, various preparation methods such as layer-by-layer deposition, 7 surface modification 8 by functional groups, and a spray drying method, 9 have been reported along with different morphologies such as core-shell, 10 hollow, 11 and raspberry. 12 In a recent study, hybrids coated with silica on the polymer surface via surface modification have been reported.…”