Effects of Water Hardness on Textile Detergency Performance in Aqueous Cleaning Systems

摘要: The effects of water hardness on textile detergency in aqueous solutions were systematically investigated using four surfactants: sodium oleate (OLNa), linear dodecylbenzene sulfonate (LAS), dodecyl sulfate (AS), and polyoxyethylene (10) ether (AE). Water was adjusted according to the standard procedure described IEC 60734:2012. As expected, by adding salts surface tension OLNa solution increased. Surprisingly, addition lowers for LAS AS solutions. In case AE solution, salt did not affect tension. A decrease transmittance foamability after observed every anionic surfactant indicating that surfactants can combine with divalent ions form insoluble precipitates. Detergency experiments performed cotton plain-woven towel fabrics soiled a carbon black oleic acid mixture. One piece each untreated fabric stacked placed horizontally detergent or without salts. mechanical action soil removal, shaking 190 spm applied. Soil removal redeposition due washing evaluated from changes values Kubelka-Munk function both fabrics. With increasing hardness, decreased order decreasing detergency, as follows: > ≈ AE. results indicate precipitates, formed reaction salts, are strongly adsorbed because their hydrophobicity, but they have no power. field emission scanning electron microscopic observation X-ray photoelectron spectroscopic analysis showed Ca(LAS)2 precipitation clung fiber surfaces, remained surfaces washing. Significant properties absorbency.