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Reversible Calcium(II)‐Ion Binding through an Apparent p K a Shift of Thermosensitive Block‐Copolymer Micelles
Author(s) -
Custers Johannes P. A.,
van Nispen Sjoerd F. G. M.,
Can Aydin,
de La Rosa Victor R.,
Maji Samarendra,
Schubert Ulrich S.,
Keurentjes Jos T. F.,
Hoogenboom Richard
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201505351
Subject(s) - copolymer , chemistry , micelle , aqueous solution , divalent , carboxylic acid , desorption , acrylate , polymer chemistry , ion exchange , adsorption , ion , calcium , inorganic chemistry , organic chemistry , polymer
There is an increasing need for smart materials capable of removing multivalent ions from aqueous streams without the inconvenience of brine regeneration as in ion‐exchange processes. Herein, we present a thermoresponsive micellar system consisting of polystyrene–poly(methoxy diethyleneglycol acrylate) block copolymer surfactants modified with carboxylic acid end groups (PS‐PMDEGA‐COOH) that can be used to switch between the adsorption and desorption of divalent calcium(II) cations by a mild temperature trigger, thus providing a new type of thermoregenerable ion‐adsorbing materials. The switch of calcium(II)‐binding capacity is demonstrated to result from a shift in the p K a value of the carboxylic acid groups by the collapse and redissolution of the PMDEGA block and the associated change in local polarity.