Studies of N-dodecyllactobionamide, maltose 6'-O-dodecanoate, and octyl-β-glucoside with surface tension, surface force, and wetting techniques

Three different types of sugar surfactants, octyl-beta -glucoside, maltose 6'-O-dodecanoate, and N-dodecyllactobionamide have been investigated to examine the effect of the structure of the sugar headgroup on the adsorption to liquid/vapor and solid/liquid interfaces using a number of techniques (surface tension, surface force apparatus, MASIF, and wetting). It was found that all the surfactants form monolayers when adsorbed to a hydrophobic interface at high concentrations. Increased headgroup flexibility leads to the. adsorption of higher amounts on both the liquid/vapor and solid/liquid interfaces, resulting in a higher van der Waals attraction between two such monolayers. Increased hydrogen bonding within layers of more flexible surfactants is suggested to explain this difference. The most flexible surfactant, N-dodecyllactobionamide, is the least efficient wetting agent with the highest gamma (SL). The behavior of the receding contact angles indicates the importance of intralayer hydrogen bonds between larger and more flexible sugar headgroups.