The relation of synergism in binary mixtures of surfactants to microenvironmental factors.
Item
-
Title
-
The relation of synergism in binary mixtures of surfactants to microenvironmental factors.
-
Identifier
-
AAI9009796
-
identifier
-
9009796
-
Creator
-
Utarapichart, Cheawchan.
-
Contributor
-
Adviser: Milton J. Rosen
-
Date
-
1989
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Chemistry, Physical
-
Abstract
-
The degree of interaction between two surfactants in mixed monolayer at the aqueous solution/air interface or mixed micelle in aqueous solution can be measured by calculating the molecular interaction parameter, {dollar}\beta\sp\sigma{dollar} and {dollar}\beta\sp{lcub}\rm M{rcub}{dollar}, respectively, from surface tension measurement, using nonideal solution theory.;Interaction between the two surfactants in polyoxyethylenated nonionic-anionic mixture decreases when the hydrophilic group in anionic is moved to a more central position. With increase in ionic strength of the solution, the values of {dollar}\beta\sp\sigma{dollar} and {dollar}\beta\sp{lcub}\rm M{rcub}{dollar} go through maxima. This may be due to the complex formation between Na{dollar}\sp+{dollar} and some ether oxygens of the polyoxyethylene chain. Temperature increase in the 25{dollar}\sp\circ{dollar}-40{dollar}\sp\circ{dollar}C range results in a decrease in the values of {dollar}\beta\sp\sigma{dollar} and {dollar}\beta\sp{lcub}\rm M{rcub}{dollar}. Interaction between polyoxyethylenated anionic and alkyl sulfate or alkyl sulfonate increases with increase in the number of oxyethylene units in the polyoxyethylenated anionic.;Effects of surfactant structure, ionic strength of the solution, and temperature on synergism in surface tension reduction efficiency and mixed micelle formation in polyoxyethylenated nonionic - anionic mixtures have been investigated. Synergism and negative synergism in surface tension reduction effectiveness were also investigated in polyoxyethylenated anionic - anionic and polyoxyethylenated nonionic - anionic mixtures, respectively.;Measurements of (Na{dollar}\sp+{dollar}) at 25{dollar}\sp\circ{dollar}C by use of a Na{dollar}\sp+{dollar} selective electrode indicate that noncyclic polyoxyethylenated (POE) nonionic surfactants, C{dollar}\sb{12}{dollar}H{dollar}\sb{lcub}25{rcub}{dollar}(OC{dollar}\sb2{dollar}H{dollar}\sb4{dollar}){dollar}\sb{lcub}\rm X{rcub}{dollar}OH (C{dollar}\sb{12}{dollar}(EO){dollar}\sb{lcub}\rm X{rcub}{dollar}), in the absence of ionic surfactants and at concentrations more than one order of magnitude above their critical micelle concentrations, complex Na{dollar}\sp+{dollar} weakly. In aqueous NaCl solutions of 0.004 M total ionic strength about 0.17 moles Na{dollar}\sp+{dollar} are complexed per mole of C{dollar}\sb{12}{dollar}(EO){dollar}\sb8{dollar}, 0.09 moles per mole of C{dollar}\sb{12}{dollar}(EO){dollar}\sb4{dollar}. In the presence of an anionic surfactant, Na di (2-ethylhexyl) sulfosuccinate (AOT), the extent of complexation is considerably increased. The complexation constant, K, increases with increase in the AOT/C{dollar}\sb{12}{dollar}(EO){dollar}\sb8{dollar} molar ratio in the mixed micelle, with complexed Na{dollar}\sp+{dollar} maintaining an approximately 1:1 molar ratio with AOT in the mixed micelle. K decreases when C{dollar}\sb{12}{dollar}(EO){dollar}\sb8{dollar} is replaced by C{dollar}\sb{12}{dollar}(EO){dollar}\sb4{dollar} or when AOT is replaced by its di - amyl analog. C{dollar}\sb{12}{dollar}(EO){dollar}\sb8{dollar}-C{dollar}\sb{14}{dollar}N(CH{dollar}\sb3{dollar}){dollar}\sb3{dollar}Br mixtures complex Na{dollar}\sp+{dollar} even more weakly than in the absence of an anionic surfactant, indicating competition between cationic surfactant and Na{dollar}\sp+{dollar} for the polyoxyethylene chain.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
