Removal of a solid organic soil from a hard surface by glucose-derived surfactants: effect of surfactant chain length, headgroup polymerisation and anomeric configuration

The ability of sugar-derived surfactants to remove a solid organic soil from a hard surface has been investigated using a quartz crystal microbalance (QCM) technique. A matrix of anomerically pure alkyl glucosides and alkyl maltosides, as well as two polydisperse commercial alkylpolyglucoside (APG) surfactant mixtures, were investigated to study the way in which surfactant structure influences hard soil detergency behaviour. As expected, the removal of the hard soil, tristearin, from the gold surface was poor at surfactant concentrations below the critical micelle concentration (CMC) but rose dramatically at higher concentrations. At high concentrations above the CMC, the amount of hard soil ultimately removed was not dependent on the surfactant structure. In contrast, the kinetics of soil removal was dependent on the headgroup degree of polymerisation (DP), alkyl chain length, and anomeric configuration for the matrix of surfactants studied. Alkyl maltoside surfactants removed the hard soil faster than the corresponding alkyl glucoside; an alkyl chain length of ten carbon atoms provided faster soil removal than the octyl or dodecyl counterpart; and at short chain lengths, the α-anomers remove tristearin faster than the corresponding β-anomer.