INTERACTION OF PHENOLIC POLLUTANTS WITH PNIPA HYDROGELS

摘要

Poly(N-isopropylacrylamide) (PNIPA) gels swollen in pure water exhibit a volume phase transition (VPT) at 34℃, above which the solvent is expelled. In contact with aqueous phenol solutions, these gels may display a VPT at 20℃ at aromatic acid concentrations, depending on the number of OH-substitutions. This observation makes PNIPA a promising actuator for phenols in water, and also offers opportunities for water treatment applications. Dynamic light scattering (DLS) data show that the product of the collective diffusion coefficient and the Rayleigh ratio of the thermodynamic fluctuations is independent of the aromatic composition below the critical concentration. It follows, as is also confirmed by small angle neutron scattering (SANS) experiments, that the phenols are not directly in contact with the network chain.