Relationship of Structure to Properties in Surfactants. 9. Syntheses and Properties of 1,2- and 1,3-Alkanediols

Article abstract of DOI:10.1021/j100442a021

A number of 1,2- and 1,3-alkanediols containing 10-15 carbon atoms in the alkyl group have been synthesized, purified, and characterized.Surface tension measurements on aqueous solutions of these compounds at 25 deg C have been used to calculate surface excess concentration, area/molecule at the aqueous solution/air interface, critical micelle concentration, efficiency and effectiveness of surface tension reduction, and standard free energy of adsorption and of micellization.The compounds appear to be adsorbed at the aqueous solution/air interface in an almost close-packed arrangement with both hydroxyl groups lying in the interface and with the alkyl chain oriented perpendicular to it.The data indicate that, in its surface properties in aqueous solution, a 1,3-alkanediol is very similar to a 1,2-alkanediol with one less carbon atom.The standard free energy of adsorption of the HOCH2CHOH- or HOCH2CH2CHOH- group at the aqueous solution/air interface is 4.3-5.2 kJ mol^-1, whereas the standard free energy of micellization of these groups in aqueous solution is 10.3-10.9 kJ mol^-1.