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Studies on Solution Behavior of Aqueous Mixtures of Nonionic Polymer in Presence of Cationic Surfactants
Author(s) -
Sardar Najam,
Kamil Mohammad
Publication year - 2017
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/s11743-017-1932-1
Subject(s) - chemistry , micelle , pulmonary surfactant , polymer , critical micelle concentration , peg ratio , aqueous solution , polyethylene glycol , counterion , aggregation number , cationic polymerization , viscosity , bromide , chemical engineering , thermodynamics of micellization , polymer chemistry , organic chemistry , thermodynamics , ion , biochemistry , physics , finance , economics , engineering
The interactions of two gemini surfactants (16– s –16, s = 5, 6) and their conventional counterpart cetyltrimethylammonium bromide (CTAB) with polyethylene glycols (PEG 3000 and PEG 35000) have been investigated using conductivity, steady state fluorescence, viscosity and TEM techniques. The results indicate that there is no interaction between the PEG 3000/CTAB complex at lower polymer concentrations. However, a very weak interaction is observed at higher concentrations (0.5 and 1.0 wt% PEG 3000), while PEG 3000 and PEG 35000 interact with the gemini surfactants. Both critical aggregation concentration (CAC) and critical micelle concentration (CMC) increases with polymer concentration but are independent of the polymer molecular weight. From steady state fluorescence it is found that the addition of PEG results in no drastic decrease in the aggregation number ( N ) for all surfactants. This suggests that the atmosphere surrounding the polyion‐bound micelles, with respect to the influence on the forces acting at the micelle surface, is equivalent to the counterion/water atmosphere surrounding free micelles. The relative viscosity ( η r ) results show an enhancement in η r for all the surfactants. The increase in η r is quite significant with gemini surfactants. Polymer‐surfactant interaction also depends on the polymer molecular weight. Also, the interaction seems to affect both inter polymer–polymer association as well as chain expansion. Additionally the surfactant induced changes in the polymer conformation depicted by TEM study at the micro structural level confirmed previously observed interactions determined by different analytical techniques.