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Polymerization-induced microphase separation has been used to prepare solid cross-linked monoliths containing bicontinuous and nanostructured polymer domains. We use this process to fabricate a monolith containing either a negatively or positively charged polyelectrolyte domain inside of the neutral styrene/divinylbenzene-derived matrix. First, the materials are made with a neutral pre-ionic polymer containing masked charged groups. The monoliths are then functionalized to a charged state by treatment with trimethylamine; small-angle X-ray scattering shows no significant morphological change in the microphase-separated structure upon postpolymerization modification. By exchanging dyes with the counterions in the material, we corroborated the continuity of the charged domains. Using ion-exchange capacity measurements, we estimate the number of accessible charges within the material based on macro-chain transfer agent molar mass and loading.

Reversible addition/fragmentation chain-transfer polymerization is used to generate a calix[4]pyrrole methacrylate-derived copolymer. The material is found to undergo supramolecular cross-linking upon exposure to select dianionic species (e.g., pyrophosphate and terephthalate salts), altering the viscoelastic properties of the copolymer in solution and in the solid state. The copolymeric material is also used for selective differentiation of mono- and bis-anions under conditions of liquid/liquid extraction.