STUDIES ON TEXTILE DETERGENCY AT LOW-TEMPERATURE

Detergent efficiency of nonionic surfactant solutions with and without electrolyte as a function of temperature has been determined. In these experiments hexadecane was chosen as a model oily soil and polyester/cotton fabrics as solid substrate. It was found that the evolution of detergent efficiency with temperature in systems containing electrolyte followed the same trends as those of systems without electrolyte: As the temperature increases detergent efficiency also increases and an optimum is reached, then a pronounced decrease is observed. However there is a shift in the temperature at which the optimum is obtained toward lower temperatures as electrolyte concentration increases. This shift has been attributed to the effect of salting-out electrolytes on the HLB-temperature of ternary water/nonionic surfactant/oil systems.