Organo silica nanosheets with gemini surfactants for rapid adsorption of ibuprofen from aqueous solutions

Gemini surfactants with different alkyl chain lengths, [C16H33-N+ (CH3)(2)-CH2](2)center dot 2Br(-) (G(16-2-16)), [C12H25-N+ (CH3)(2)-CH2](2)center dot 2Br(-) (G(12-2-12)), and [C8H17-N+ (CH3)(2)-CH2](2)center dot 2Br(-) (G(8-2-8)), were applied to modify Silica nanosheets (SiNSs). FT-IR, XRD, TG, SEM, TEM, BET and Zeta potentials were carried out to study the surface and structure of the resultant organo silica nanosheets (organo-SiNSs). The loading amounts of G(16-2-16), G(12-2-12), and G(8-2-8) were 0.23, 0.14, and 0.09 mmol for 1g SiNSs, respectively, suggesting the increased length of the alkyl chain promoted the modification process. Organo-SiNSs exhibited rapid adsorption property (within 5 min) and high adsorption capacity (64.19 mg g(-1)) toward ibuprofen (IBP) at such a low surfactant concentration (0.42 mmol for 1 g SiNSs), and can be regenerated at least for 3 cycles. Furthermore, the longer the alkyl chain, the more IBP removed, the adsorption capacities of three organo-SiNSs decreased in the order G(16-2-16)-SiNSs (64.19 mg g(-1))> G(12-2-12)-SiNSs (40.14 mg g(-1))> G(8-2-8)-SiNSs (4.84 mg g(-1)). Moreover, electrostatic interaction as well as the partition effect plays an important role in the adsorption. Based on the fast adsorption and cost-effective feature, organo-SiNSs were further proved to be outstanding adsorbents for specific organics removal. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.