Thermo-Responsive Transport Behavior Through Porous Membranes with Linear-Grafted Poly(N-isopropylacrylamide) Gates

摘要

Both thermo-responsive flat membranes and core-shell microcapsule membranes, with a porous membrane substrate and grafted poly(N-isopropylacrylamide) (PNIPAM) gates, were successfully prepared using a plasma-graft pore-filling polymerization method. PNIPAM was proven to be homogeneously grafted onto the porous membrane substrates not only in the direction of the membrane thickness but also in the direction of the membrane surface. Regardless of the molecular size of solute, temperature has an opposite effect on the diffusional permeability coefficients of solutes across the PNIPAM-grafted membranes with low and high graft yields. Phenomenological models for predicting the diffusional permeability of solute across the PNIPAM-grafted membranes at temperatures both above and below the LCST were developed in this study. The predicted diffusional coefficients of solutes across both the PNIPAM-grafted flat membranes and the PNIPAM-grafted microcapsule membranes were proven to fit in with the experimental values.