Physical gels are interesting candidates for a multitude of applications, because physical gels are self-healing and responsive.
Recently, we have succeeded in preparing a physical gel based on electrostatic interactions only. These gels can be prepared by mixing a triblock copolymer with charged end-blocks and a neutral middle-block, with an oppositely charged homopolymer. At low concentrations flowerlike micelles are formed, which can become interconnected at higher concentrations, see figure. Because electrostatic interactions are the driving force for association, these gels are multi-responsive, i.e. the properties of these gels can be tuned by concentration, temperature, charge composition, ionic strength, pH, block lengths, type of (poly)electrolyte pair, type of counter ions and solvent conditions.