Reinforced Rhodamine B adsorption on the hyper-cross-linked resin co-modified by pyridine and carboxyl groups

Hyper-cross-linked resin has enormous potential in the removal of organic dyes from aqueous solutions due to its adjustable porous structure and designable chemical properties, whereas its poor adsorption capacity limits the application. In this study, the co-modified hyper-cross-linked resin (HCP-x) with tunable porosity was synthesized by adjusting the dosages of 4-vinylpyridine (4-VP) and 4-vinylbenzoic acid (4-VA) in the polymerization process. The results indicated that pores in the range of 4–12 nm show up in HCP-x resin with the addition of 4-VP and 4-VA. Particularly, the polymer containing 10% by weight of monomer (HCP-90) had the highest specific surface area, the largest micropore volume and a bigger mesoporous volume in the terpolymer. The adsorption experiment results demonstrated that HCP-90 showed 4 times increased Rhodamine B adsorption than the original resin. This study described a simple method to co-modify the hyper-cross-linked resin by introducing two functional monomers, and the modified material was potential for Rhodamine B adsorption.