The transition behavior of swelling and deswelling of water-soluble poly(N-isopropylacrylamide) was calculated by a decorated UNIQUAC model with blob concept. The deswelling behavior of hydrogels at high temperatures was also reported with shrinking volumes during the transition. Polymer chains were scaled within a directly interacting size as blobs, which are composed of a segmentalized polymer chain and solvent molecules and counted blobs of hypothetical components or segments. The interaction parameters of bulks, UNIQUAC interaction parameters,
were approximated with temperature-independent site interaction energies following the blob renormalization transformation. The swelling gel transition volume at each given temperature was calculated with the decorated UNIQUAC model. The blob rescaling model successfully described the first order transition of swelling-deswelling behaviors.
Bae YH, Okano T, Kim SW, J. Polym. Sci. B: Polym. Phys., 28, 923, 1990
Ban YB, Kim YC, Kim JD, Fluid Phase Equilib., 53, 331, 1989
Bondi A, "Physical Properties of Molecular Crystals, Liquid and Glasses," Sheel Development Co., 1968
Chun SW, "Thermoresponsive Characteristics of Complex Membrane of Poly (N-Isopropyl Acrylarnide) Hydrogel Embedded in Polymer Matrix," Ph.D. Dissertation, KAIST, 1995
Chun SW, Kim JD, J. Control. Release, 38, 39, 1996
Dong LC, Hoffman AS, J. Control. Release, 15, 141, 1991
Flory PJ, "Principles of Polymer Chemistry," Cornell University Press, Ithaca, NY, 1953
Gehrke S, Cussler EL, Chem. Eng. Sci., 44, 559, 1989