Nano-silica hybrid SDB carriers with high strength and hydrophobicity: synthesis, characterization and their application as sorbents of Ni2+

Abstract

In Liquid Phase Catalytic Exchange (LPCE), the strength and hydrophobicity of styrene-divinylbenzene copolymer (SDB) carrier are key limitation factors for practical applications. In this paper, a surface-modified nano-SiO2 (KH570-SiO2) was used to improve the strength and hydrophobicity of SDB. Then, copolymerization of KH570SiO2 with St, DVB to produce KH570-SiO2/SDB, Divinyl benzene (DVB), styrene (St) glycidyl methacrylate (GMA) to produce KH570-SiO2/GMA/SDB. The two kinds of new carriers were characterized by scanning electron microscope, static water contact angle, N2 adsorption–desorption, transform infrared spectrometry and thermogravimetric analysis. Compared with SDB, both KH570-SiO2/SDB and KH570SiO2/GMA/SDB show better performances, such as a higher hydrophobicity(147° and 145°, respective), a higher strength(107.11 N and 115.37 N, respectively), a better thermal stability(373.8 and 435.67 ℃, respectively), and a larger specific surface area(487.253 and 463.673 m2/g, respective). The Nickel ion was uesd as the model ion of Platinum ion. And then the Ni2+ adsorption performances of KH570-SiO2/SDB and KH570-SiO2/GMA/SDB were studied. Experiments show that KH570-SiO2/GMA/SDB has a much higher adsorption rate and a bigger adsorption amount. Refinement indicates that the adsorption behaviors of SDB, KH570-SiO2/SDB and KH570-SiO2/GMA/SDB with Ni2+ are according to pseudo-first-order kinetic. The adsorption of SDB and KH570-SiO2/GMA/SDB obeyed Freundlich isotherm, while the adsorption of KH570-SiO2/SDB obeyed Langmuir isotherm.