Preparation of copolymer brush-type restricted access microspheres with adjustable adsorption selectivity to variety of dyes

Restricted access materials (RAMs) with adjustable selectivity was developed for the removal and detection of residual dyes for the solve problems of dye contamination. In this work, using homemade poly(4-vinylbenzyl chloride-co-divinylbenzene) (P-VBC/DVB) microspheres as substrate and successive two-step surface-initiated atom transfer radical polymerization (SI-ATRP) as synthesis method, the two types of monomers, sodium 4-vinylbenzene sulfonate (Nass) and styrene (St) were first grafted for constructing mixed interactions of adsorption sites, and then the hydrophilic glycidyl methacrylate (GMA) was polymerized, following by hydrolysis to construct diol groups on the external P-VBC/DVB as the restricted access sites. The developed P-VBC/DVB@poly(St-co-Nass)@poly(GMA) of adsorption properties was investigated by six dyes including methylene blue (MB), basic fuchsin (BF), acid fuchsin (AF), neutral red (NR), methyl orange (MO), and Congo red (CR), the adsorption capacities of those dyes and the removal rate for the binary mixed dye solution both rely on the ratio of St/Nass, confirming the adjustable adsorption selectivity. When P-VBC/DVB@poly(St-co-Nass)@poly(GMA) was packed as solid phase extraction adsorbent in couple with UV-vis spectrum, it was applied to the determination of MB and BF in the water, fish and shrimp, good linearity with satisfactory recoveries for MB and BF are obtained to show the favorable practicability.