High swelling ability of polystyrene-based polyelectrolyte gels at low temperature

Molecular design of polymer gels that exhibit high swelling degrees at low temperature was demonstrated with the aid of repulsive interaction among the polymer chains in the ionic polymer gels and the utility of organic solvents with relative low melting points. A small amount of tetraalkylammonium tetraphenylborate as ionic groups was incorporated into cross-linked polystyrene to yield novel ionic polymer gels. The swelling degrees at room temperature (23 °C) were about 100 times as much as their dried weights in various organic solvents. Moreover, they swelled and absorbed some organic solvents such as THF and dichloromethane at low temperature (−80 °C), and the swelling degrees were similar to those at room temperature.