Thermoreversible crystallization of charged colloids due to adsorption/desorption of ionic surfactants.

•Colloidal dispersions crystallized thermoreversibly via ionic surfactant adsorption.•The colloids crystallized on cooling and melted upon heating.•The mechanism was studied by using polystyrene particles in ethylene glycol/water.•The crystallization was caused by a decrease in the ionic strength of the medium.•The present findings will be useful for fine control of colloidal crystallization.