Scheme 4.
Volume changes ([%]) induced by different anions on the PMMA-derived polymer I; [NaX] = 0.10 M; left bars (always expansion): in pure water, pH 7.3; right bars (partially contraction), in presence of 0.02 M phosphate buffer, pH 7.0. Copyright Wiley-VCH Verlag GmbH & Co. [39a].