Bathing detersive systems

Although it is impossible to Hst all the practical detersive systems that might be encountered, a large proportion fall in a small number of classes. This classification disregards surfactant stmcture and type of substrate (fibrous or hard surface) and is restricted to a consideration of the soil present on the substrate, the mechanical action employed, the bath ratio, and the detergent used. Some of the more commonly encountered detersive systems are classified on this basis in Table 1. 

Adsorption of bath components is a necessary and possibly the most important and fundamental detergency effect. Adsorption (qv) is the mechanism whereby the interfacial free energy values between the bath and the soHd components (sofld soil and substrate) of the system are lowered, thereby increasing the tendency of the bath to separate the soHd components from one another. Furthermore, the soHd components acquire electrical charges that tend to keep them separated, or acquire a layer of strongly solvated radicals that have the same effect. If it were possible to foUow the adsorption effects in a detersive system, in all their complex ramifications and interactions, the molecular picture of soil removal would be greatly clarified. 

In a detersive system containing a dilute surfactant solution and a substrate bearing a soHd polar sod, the first effect is adsorption of surfactant at the sod—bath interface. This adsorption is equivalent to the formation of a thin layer of relatively concentrated surfactant solution at the interface, which is continuously renewable and can penetrate the sod phase. Osmotic flow of water and the extmsion of myelin forms foHows the penetration, with ultimate formation of an equdibrium phase. This equdibrium phase may be microemulsion rather than Hquid crystalline, but in any event it is fluid and flushable... 

Inter facial Parameters in the Detersive System. Three phases are present in the detergency system in this study a PEG (fiber), a hydrocarbon (soil), and an aqueous surfactant (bath) phase. These three phases meet to form three binary interfaces, whose interfacial energetic properties vary as a function of LAS homolog molecular weight. 

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