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Dissolution of Soap Scum by Surfactant Part I: Effects of Chelant and Type of Soap Scum
Author(s) -
Itsadat Sawwalak,
Scamehorn John F.,
Soontravanich Sukhwan,
Sabatini David A.,
Chavadej Sumaeth
Publication year - 2014
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/s11743-013-1544-3
Subject(s) - chemistry , solubility , pulmonary surfactant , chelation , magnesium , dissolution , stearate , inorganic chemistry , nuclear chemistry , organic chemistry , biochemistry
The equilibrium solubilities of two model soap scums [calcium stearate and magnesium stearate: Ca(C 18 ) 2 and Mg(C 18 ) 2 ] were measured in aqueous solutions containing three different types of surfactants: methyl ester sulfonate (MES) as an anionic; alcohol ethoxylate (EO9) as a nonionic; and dimethyldodecylamine oxide (DDAO) as an amphoteric with and without a chelating agent [disodium ethylenediaminetetraacetate (Na 2 EDTA)]. The solubility of calcium soap scum was generally higher than that of magnesium soap scum, the exception being some DDAO systems. The use of the DDAO surfactant with the Na 2 EDTA chelating agent at high pH gives the highest solubilities of both studied soap scums. The soap scum solubility is on the order of 2,000 times that in water at high pH. The DDAO is the most effective surfactant under all conditions. The MES is more effective than the EO9 at low pH with the opposite trend observed at high pH. The synergism from added chelant is generally greater at higher pH and is greatest for DDAO followed by EO9.