Surface properties of diluted solutions of n-heptane, n-octanol and n-octanoic acid in nitromethane

The surface tensions a of solutions of n-heptane, n-octanol and n-octanoic acid (caprylic acid) in nitromethane were measured in the temperature range between 278 and 308 K using Wilhelmy plate method. Untypical parabolic sig ma = f(T) dependences were observed for all the three systems under investi gation. The surface entropies and compositions were calculated. The results were interpreted in terms of formation of specific monolayer structures fo rmed by solute molecules adsorbed at the interface and similarities between interfacial properties of the systems under investigation and the aqueous ones. (C) 2001 Elsevier Science B.V. All rights reserved.