Synthesis of hybrid microspheres from zirconium butoxide and an ionic–non-ionic copolymer

Abstract

This work presents the synthesis and characterization of hybrid microspheres made of hydrated zirconium oxide and an organic copolymer. The synthesis was carried out in a two-stage procedure. First, the polymer microspheres were synthesized via the inverse emulsion polymerization of 4-vinyl benzyl trimethyl ammonium chloride (ClVBTA) and 2-hydroxy ethyl methacrylate (HEMA), and second, the copolymeric beads were impregnated with an inorganic precursor (Zr(ButO−)4) to form the hybrid through a sol-gel reaction. Several experimental variables were controlled in both stages of the synthesis, such as the formulation of the emulsion, concentration of the surfactant, molar ratio of the monomers, concentration of the inorganic precursor, and soak time. Well-defined microspheres with low polydispersity were obtained with a volume ratio of 0.2 and a low Span 80 surfactant concentration. While an increase in the ClVBTA/HEMA molar ratio enhanced the hydrophilicity of the particles, it did not necessarily increase the incorporation of oxide. Additionally, an increase in ClVBTA/HEMA decreased the resistance of the composite microspheres to the osmotic shock, resulting in rupturing of the beads. This polymer hybrid microspheres can be used in applications where surface processes are involved.