Preparation of silica nanoparticle based polymer composites via mussel inspired chemistry and their enhanced adsorption capability towards methylene blue

Abstract

The highly efficient removal of environmental pollutants from aqueous solution using low cost adsorbents has recently attracted great research attention. Among them, polymer nanocomposites should be some of the most important candidates for adsorption applications because of their combination of the advantages of both nanomaterials and polymers. In this work, a bioinspired strategy has been developed for the fabrication of silica nanoparticle based polymer composites, which were used as low cost and highly efficient adsorbents for the removal of methylene blue. First, poly(SVS-co-ITA) copolymers were synthesized by free radical polymerization using 4-vinylbenzenesulfonate and itaconic anhydride as monomers. Then dopamine was linked with poly(SVS-co-ITA) through a rather facile ring-opening reaction. The final SiO₂@poly(SVS-co-ITA–DA) polymer nanocomposites were obtained by attaching poly(SVS-co-ITA–DA) onto silica nanoparticles taking advantage of dopamine adhesion. The structure, morphology and chemical compositions of SiO₂@poly(SVS-co-ITA–DA) polymer nanocomposites were characterized by a number of methods in detail. The effect of adsorption parameters, including contact time, concentration of methylene blue, temperature and pH, on adsorption capability have been investigated. The adsorption data was fitted by Langmuir and Freundlich adsorption models. The pseudo-first-order, pseudo-second-order and intra-particle diffusion models were used for kinetic analysis. We found that the adsorption capacity of SiO₂@poly(SVS-co-ITA–DA) nanocomposites is much greater than that of raw SiO₂ NPs. Taken together, we have developed a bioinspired strategy to prepare silica nanoparticle based polymer nanocomposites with improved performance for environmental applications.