title: Bile-salt-induced aggregation of poly(N-isopropylacrylamide) and lowering of the lower critical solution temperature in aqueous solutions.
abstract: The effect of sodium cholate (NaC; concentration 1-16 mM), a biological surfactant, on the aggregation behavior of 1% (w/v, 2.2 × 10(-3) M) poly(N-isopropylacrylamide) (PNIPAM) aqueous solutions was studied as a function of temperature. From turbidity, dynamic light scattering, viscosity, and fluorescence measurements, it was observed that (i) there is NaC-induced nanoscale aggregation of PNIPAM in its sol state and (ii) the lower critical solution temperature corresponding to sol-gel transition shifts to a lower temperature by about 2 °C.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Madras 600036, India.
authors.forename: Anitha C
authors.initials: AC
authors.lastname: Kumar
authors.forename: Harikrishna
authors.initials: H
authors.lastname: Erothu
authors.forename: Himadri B
authors.initials: HB
authors.lastname: Bohidar
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Mishra