Electro-driven chemomechanical polymer gel as an intelligent soft material

Weakly crosslinked poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel was synthesized and the chemomechanical behaviors in the presence of N-alkylpyridinium chloride (CnPyCl n = 4, 12, 16) were studied. The principle of this behavior is based upon an electrokinetic molecular assembly reaction of surfactant molecules on the polymer gel caused by both electrostatic and hydrophobic interactions. Under an electric field PAMPS gel underwent significant and quick bending and the response could be controlled effectively by changing the alkyl chain length of the surfactant molecule, the salt concentration, and the current applied. The results allow us to consider that cooperative complex formation between PAMPS gel and CnPyCl is responsible for this effective chemomechanical behavior.