SURFACE TENSIONS AND RELATIVE ADSORPTIONS IN HYDROGEN-BONDED SYSTEMS

Liquid-air interfacial tensions of representative alkanol + alkane and alkanol + amine systems measured by the differential capillary rise t echnique at 298.15 K are reported. The binary systems studied are hexa ne + ethanol and + 1-propanol, heptane + ethanol and + 1-propanol, and n-butylamine + methanol, + ethanol, and + 1-butanol. The excess surfa ce tensions in the alkanol + alkane systems are negative, while in the alkanol + amine systems they are positive. The surface tensions thems elves for the alkanol + amine systems, when plotted against mole fract ion, exhibit a maximum. The two classes of systems exhibit characteris tic patterns in their relative adsorptions. The results are discussed in relation to the bulk properties of these hydrogen-bonded systems.