Journal Article 1302-78-9 2D channels 7782-42-5 9002-89-5 Bentonite Electrolytes Graphite Polyvinyl Alcohol Protons anion transport bottom-up synthesis covalent organic framework covalent organic framework membranes de novo design graphene composite graphene oxide humidity dependence ion membranes nacre structures nanochannels, proton conduction phase-transfer polymerization proton conduction side-chain engineering solid electrolyte membranes