抄録
Under high hydrostatic pressures up to 1500 bar, the diffusion coefficients, D, were measured at 80°C for p-aminoazobenzene (pAAB) in cellulose diacetate swollen with water and benzene. From the pressure dependence of D, the activation volume, ΔV_??_, for the diffusion was found to be 20.9cm3/mol for the water and 39.5cm3/mol for the benzene swollen system. The degree of swelling, S, of the polymer was more than twice as large in benzene (S=19.8%) as in water (S=7.5%). The observed ΔV_??_ values as combined with those of S were not in accordance with the expectation that ΔV_??_ decrease with increasing degree of swelling which supplies the larger free volume. It was proposed that the solvation of pAAB by benzene gives the reason for the unexpectedly larger ΔV_??_ value observed.
