| Research Abstract |
An accurate and rapid method for the evaluation of soil removal has been developed. It may be used to analyze the thermodynamics which oily soil substances are removed from a fiber substrate into an aqueous detergent solution.
A liquid chromatography method with fiber power, textile yarn, or woven fabric as stationary phase has been devised for studying the mechanism by which oily soils are removed from a fiber substrate with surfactant. We measured the retention volume of oily soil substrate on polyester or cellulose substrate stationary phase as a function of the aqueous surfactant micelle concentration in the mobile phase.
The oily substrate elution volumes and capacity factors were affected by micelle concentrations in the mobile phase. The partition coefficients of the oily substances between the fiber substrate and micelles (PィイD2smィエD2, between the fiber substrate and water (PィイD2swィエD2), and between micelles and water (PィイD2mwィエD2) were determined with the chromatographic treatment involving micellar mobile phases. The PィイD2smィエD2 and PィイD2swィエD2 values for the oily substances were larger for the polyester system than for the cellulose system. The changes in free energy (-Δμ) of oily substances between the micelles and fiber substrate equaled 2.9 〜 3.3 kcal / mol for polyester, and 4.3 〜 4.5 kcal / mol for cellulose, respectively, suggesting that oily substances are much more difficult to remove from polyester than from cellulose.
These results are similar to those observed by other investigators using other methods. This chromatography technique may be useful for investigating the dynamic equilibrium between removal and redeposition of oily substances a fabric substrate in detergent solution.
|
