Adsorption and desorption of detergent components onto an electrode-separated piezoelectric quartz crystal coated with and without collagen

Abstract

Sodium oleate, which is the main component of commercial solid soaps, was adsorbed on a quartz plate coated with and without collagen by means of electrode-separated piezoelectric quartz crystal measurements. Sodium dodecylbenzenesulfonate (DBS), which is the main component of commercial liquid detergents, was also adsorbed on collagen, but was not on the quartz plate. The frequency shifts caused by the adsorption of sodium oleate or DBS remained even if water was flowed. It was supposed that the soap components adhered onto glasses, dishes and human skin would remain as if they were rinsed with water and hot water. The sodium oleate and DBS were adsorbed in a weak acid solution and at high temperature, and desorbed in 0.01% of sodium carbonate or 0.05% of a sodium hydrogencarbonate solution.