Synthesis and characterization of highly durable and reusable superabsorbent core-shell particles

Superabsorbent core-shell particles were synthesized via a two-step process. A silica core was prepared by co-condensation of tetraethyl orthosilicate and vinyl triethoxysilane. The vinyl-functionalized silica particles were then polymerized with acrylamide monomer via free-radical polymerization to yield silica-polyacrylamide (PAM) hybrid particles. The crosslinking density and porosity of PAM on the hybrid particles were controlled by adjusting the concentration of the crosslinker, n,n '-methylenebisacrylamide (MBA). The structure of core-shell particles was confirmed by scanning and transmission electron microscopy techniques. The hybrid particles with 3.0%MBA could absorb water up to 70 g/g. These hybrid particles also removed 80% of methylene blue from solution within 24 h and this efficacy was maintained for seven cycles. The weight remaining of the hybrid particles after nine cycles was higher than that of pure PAM after three cycles indicating the high durability and reusability of the core-shell particles. POLYM. ENG. SCI., 2019. (c) 2019 Society of Plastics Engineers