Temperature controlled release from polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene block copolymer hydrogel

We report temperature controlled release from thermo-responsive polystyrene-block-poly(N-isopropyl acrylamide)-block-polystyrene triblock copolymer hydrogel. The hydrogel swelling and release of water soluble methyl orange are studied as a function of temperature for bulk and for two nano-confinements: cylindrical electrospun nanofibres and spherical aerosol nanoparticles. The time for 80% release from bulk hydrogel is found to be dependent on temperature. At room temperature the 80% release takes in 3 h whereas at 40 °C the same release takes 60 h. The swelling was found to be dependent on temperature and polymer composition.