Premium
Dissolution Study of Salt of Long Chain Fatty Acids (Soap Scum) in Surfactant Solutions. Part I: Equilibrium Dissolution
Author(s) -
Soontravanich Sukhwan,
Lopez Heyde E.,
Scamehorn John F.,
Sabatini David A.,
Scheuing David R.
Publication year - 2010
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-010-1208-5
Subject(s) - chemistry , solubility , pulmonary surfactant , dissolution , stearate , salt (chemistry) , micelle , calcium , calcium stearate , inorganic chemistry , aqueous solution , organic chemistry , biochemistry , raw material
Dissolution of calcium salt of a long chain fatty acid or soap scum is a major challenge for hard surface cleaners since soap scum forms when soap is exposed to hard water and has very low water solubility. In this paper, the aqueous equilibrium solubility of calcium octadecanoate (or calcium stearate) was measured as a function of pH as well as chelating agent (ethylenediaminetetraacetate disodium salt) and surfactant concentrations. Anionic, nonionic, and amphoteric surfactants were studied. The highest soap scum solubility was observed at high pH with an amphoteric surfactant. Under this condition, the chelant effectively binds calcium, and the stearate anion forms mixed micelles well with the amphoteric surfactant, which is in zwitterionic form at high pH.