Calorimetric Studies on the Coil-Helix Transition of Poly (L-Lysine) in Water-Organic Solvent Mixtures
1982 年 9 巻 1 号 p. 2-7
詳細
1982 年 9 巻 1 号 p. 2-7
By combining the heat of dilution of solution of poly (L-lysine) in water-organic solvent mixtures with corresponding heat of mixing of water-organic solvent system, the integrated heats of the coil-helix transition of poly (L-lysine) were estimated to be about -6.8kJ in ethanol, -16.0kJ in isopropanol, and 10.5kJ per mole of constitutional repeating unit in N, N-dimethylformamide (DMF), respectively. The solvent composition at which the transition occurs was determined to be about 0.74 of volume fraction of ethanol, 0.74 of volume fraction of isopropanol, and 0.84 of volume fraction of DMF, respectively. Those results are in good agreement with those obtained by optical rotatory dispersion (ORD). In addition, the solvent composition at the transition point of poly (L-lysine) in water-N, N-dimethylacetamide (DMAc) solvent mixtures was also determined to be about 0.83 of volume fraction of DMAc by ORD.
