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Effects of additives on the cloud points of selected nonionic linear ethoxylated alcohol surfactants
journal contribution
posted on 2009-08-20, 00:00 authored by Jingliang LiJingliang Li, D S Bai, B H ChenEffects of various additives including inorganic salts, nonionic and ionic surfactants, water-soluble polymers and alcohols on the cloud points of three linear nonionic surfactants, Tergitol 15-S-7, Tergitol 15-S-9 and Neodol 25-7, were investigated. These surfactants are readily biodegradable and either linear primary or secondary ethoxylated alcohols. Cloud points of these surfactants were functions of their concentrations and concentrations of additives. The cloud points of nonionic surfactant mixtures lay in between the cloud points of individual component surfactants. Presence of two ionic surfactants, sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB), increased the cloud point of 1 wt% Tergitol 15-S-7 micellar solution dramatically when concentrations of ionic surfactants approaching their critical micelle concentration. Addition of water-soluble polymers decreased the cloud point, while addition of inorganic salts can either increase or decrease the cloud points. However, the effect of an alcohol additive on cloud point was dependent on its chain length or its water solubility. Interestingly, synergistic effects between sulfate or phosphate and pentanol on depression of cloud points of Tergitol 15-S-9 were discovered. A linear model predicting cloud points of Tergitol 15-S-X (X = 7, 9 and 12) surfactants and Neodol 25-X (X = 7, 9 and 12) surfactants were proposed with a correlation to logarithm of their ethylene oxide numbers.
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Journal
Colloids and surfaces A : physicochemical and engineeringVolume
346Issue
1-3Pagination
237 - 243Publisher
ElsevierLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
0927-7757eISSN
1873-4359Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2009, ElsevierUsage metrics
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