Aqueous solutions of copolymers, consisting of N-isopropylacrylamide (NIPA) and optically active N-acryloyl-L-alanine (NALA) (poly(NIPA-co-NALA)), exhibited phase-separation temperatures (cloud point, T-c), and they were soluble at the lower temperatures and phase-separated at the higher temperatures. The T-c, decreased with increasing NALA composition and increased with increasing pH of the solutions. The results of T, measurements in the presence of NaCl and a urea derivative and Fourier transform infrared measurements with a curve-fitting method indicated that an increase in the composition of NALA in the copolymers induced hydrogen bonding in and between the copolymer chains. The partition coefficient (K) and diffusion coefficient (D) of R- and S-[1-(dimethylamino)ethyl]ferrocene (DMAEFc) in poly(NIPA-co-NALA) gels in aqueous solutions were estimated by a membrane permeation method. Negligible difference was observed for K between R- and S-DMAEFc; however, D of R-DMAEFc became smaller than that of S-DMAEFc when the gels started to collapse.