Transport properties of liquid alcohols investigated by IQENS, NMR and DLS studies

Abstract

We present new results, obtained by integrated application of different techniques (IQENS, NMR, DLS and viscosity measurements), on three alcohols, (n=1, 7, 9), namely ethanol, octanol and decanol. The revealed temperature dependence of the transport coefficients allows us to frame these H-bonded systems in the moderately strong Angell kinetic classification. The translational diffusion coefficient scales with the chain length, so suggesting that the diffusing entities do not present coiling effects. Furthermore, a fast and a slow rotational diffusive process have been identified. The former, revealed by both IQENS and DLS techniques, has been connected with the fast rotational jumping of the group. The latter makes the evaluation of the static correlation factor possible, after a comparison of the neutron and the DLS data. Finally, the translational and reorientational dynamics of these H-bonded systems is discussed within the framework of the current theories.