Poly(N-isopropylacrylamide) Latices Prepared with Sodium Dodecyl Sulfate

Stable aqueous colloidal dispersions of cross-linked poly(N-isopropylacrylamide), polyNIPAM, were prepared by aqueous dispersion copolymerization of NIPAM with methylenebisacrylamide, BA, in the presence of sodium dodecyl sulfate, SDS. Below 32°C the particles were highly swollen with water and had average diameters in the range 400-800 nm. Above 32°C the average diameters decreased by a factor of 2. Swelling showed the expected trends with …