Study on the morphology and temperature-sensitivity of poly(N-isopropylacrylamide-co-acrylic acid) microgel by atomic force microscope

A group of crosslinked poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AAc)) microgels with different amount of acrylic acid (AAc) were synthesized by surfactant-free emulsion polymerization. The morphology and environmental sensitivity were studied by atomic force microscope (AFM). It was founded that the microgel particles were monodispersed and the diameter of the dried microgel latex particles was about 800nm. Moreover, the volume of the microgel particles decreased as the environmental temperature increased from 15oC to 50oC, which revealed the temperature-sensitivity of P(NIPAM-co-AAc)) microgel.