Bisphenol A adsorption in aqueous medium by investigating organic and inorganic components of hybrid polymer (polyvinylpyridine/SiO2/APTMS)

Abstract

The synthesis, characterization, and evaluation of new hybrid polymers towards bisphenol A (BPA) adsorption in aqueous medium were described. Different parameters related to the synthesis, such as catalyst nature, solvent type and the influence of 4-vynilpyridine (4-VP), 3-aminopropyltrimethoxysilane (APTMS) and tetraorthosilicate (TEOS) were investigated. The synthesized materials were named as polyvinylpyridine/SiO2/APTMS, polyvinylpyridine/SiO2, and polyvinylpyridine and characterized by FT-IR, SEM, TGA, elemental analysis and nitrogen adsorption/desorption measurements, as well as by kinetics and isotherms assays. From textural data results and binding adsorption assays, it was observed that the presence of APTMS in the hybrid polymer (polyvinylpyridine/SiO2/APTMS) gives rise to a adsorbent with lower adsorption capacity towards BPA and lower porosity. On the other hand, the presence of TEOS in the hybrid polymer (polyvinylpyridine/SiO2) provided a substantial improvement on the surface area and satisfactory adsorption capacity towards BPA compared with polyvinylpyridine/SiO2/APTMS. The organic polymer polyvinylpyridine, in turn, presented a slight superior adsorption capacity towards BPA (295 mg g−1) and lower surface area (75.1 m2 g−1) compared with polyvinylpyridine/SiO2 (232 mg g−1 and 132.5 m2 g−1), but drawbacks of overpressure when packed into extraction columns, which limits its use in solid phase extraction (SPE) procedures. Therefore, polyvinylpyridine/SiO2 has demonstrated the best performance towards BPA adsorption in aqueous medium, thereby showing the symbiosis of organic and inorganic components for obtaining materials with complementary properties.