Premium
Studies on surface activity of linear alkylbenzene sulfonates II: Effect of water hardness
Author(s) -
Kumar Raj,
Bhat S. G. T.
Publication year - 1987
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02636393
Subject(s) - pulmonary surfactant , surface tension , linear alkylbenzene , adsorption , critical micelle concentration , aqueous solution , chemistry , logarithm , precipitation , chemical engineering , micelle , thermodynamics , materials science , inorganic chemistry , organic chemistry , mathematics , physics , mathematical analysis , biochemistry , meteorology , engineering
Adsorption behavior of a mixture of homologs and isomers of sodium linear alkylbenzene sulfonates from their aqueous solutions in hard water at the solution/air interface has been investigated. Increasing the concentration of surfactant in hard water results in the precipitation of the surfactant, which starts redissolving in the solution with further increases in surfactant concentration beyond a certain value characteristic of the surfactant, and finally results in a clear solution. Surface tension versus the logarithm of concentration curves shows an unusual behavior of multiple breaks. Attempts have been made to explain the results in terms of the equilibrium existing among the different forms of the surfactant, namely monomer, precipitate and the micelle.