(55b) Characterization of Cationic Poly(N-isopropylacrylamide- co-N- 3-aminopropyl(methacrylamide)-Co- Methacryloyoxybenzophenone) Thin Film Hydrogels
AIChE Annual Meeting
2016
2016 AIChE Annual Meeting
Liaison Functions
Undergraduate Research Forum I
Sunday, November 13, 2016 - 3:45pm to 4:00pm
solution temperature (LCST) undergoing a reversible coil-to- globule transition at 32-33°C. Above this
temperature, the polymer switches from being hydrophilic to hydrophobic, and coalesces out of
solution. It is well known that small amounts of salts copolymerized with PNIPAAm can raise or lower
the LCST of NIPAAm significantly. Moreover, copolymerization of NIPAAm with other monomers can
introduce reactivity to stimuli other than temperature, such as pH, ultraviolet (UV) light, magnetism,
electric current, etc. In the present work, the influence of a cationic co-monomer, N-3-
aminopropyl(methacrylamide) (3AMA), was investigated on the swelling properties of thin film
hydrogels of PNIPAAm copolymerized with methacryloyoxybenzophenone. The copolymers showed
reactivity to both pH and temperature depending on the percentage of the 3AMA. The cloud point
properties of the bulk solutions were measured and compared to the swelling response of the
corresponding hydrogel film. The films were prepared by spin coating the copolymer and then
irradiation with UV light was used to induce cross-linking of the benzophenone groups. The swelling
behavior of the thin hydrogel films was characterized with both ellipsometry and FTIR.