Behavior of double stimuli-responsive copolymer of N-(3-(diethylamino) propyl)-N-methylacrylamide and N,N-diethylacrylamide in aqueous solutions

Double stimuli-responsive copolymer of N-(3-(diethylamino)propyl)-N-methylacrylamide and N,N-diethylacrylamide (molar mass M approximate to 32,000gmol(-1)) in buffer solutions was studied by the static and dynamic light scattering and turbidimetry. The experiments were performed within pH interval from 7 to 13 and in a wide concentration range. Two types of scattering species were observed in solutions of all concentrations and pH at room temperatures. They were macromolecular unimers and loose aggregates. The increase in concentration and pH led to decrease in phase separation temperatures and width of phase transition.