A bioinspired multifunctional heterogeneous membranecomposed of a block copolymer (PS-b-P4VP) membrane and a porous anodic alumina membrane is fabricated. The ionic rectification is so strong that the maximum ratio is ≈489, and the chemical actuation of the anion or cation gate from the “OFF” to the “ON” state promotes a 98.5% increase in the channel conductance. Advanced Materials, 2015 Bioinspired multifunctional heterogeneous membrane. a) Schematic of the biological multifunctional OmpF porin (left) with ionic selectivity, ionic gating, and ionic rectification properties driven by external pH stimuli, and the bioinspired heterogeneous membrane (right) composed of a block copolymer membrane and a PAA membrane exhibiting similar functions. b) Schematic of the heterogeneous membrane. c) Reversible pH-responsive behavior of the BCP nanochannels. d) Liquid-phase AFM images of the BCP membrane immersed in 10 × 10−3m KCl solutions with pH values varying between 3.0 and 11.0. e) The pI of alumina is ≈8–9, and its charge depends on the environmental pH. |