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Rheological and Microstructural Behavior of a Model Concentrated Fabric Softener
Author(s) -
Calero N.,
Alfaro C.,
García C.,
Berjano M.,
Lluch Á.,
Muñoz J.
Publication year - 2011
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201100020
Subject(s) - pulmonary surfactant , shear rate , ternary operation , rheology , shear (geology) , materials science , chemical engineering , aqueous solution , shear flow , ternary numeral system , composite material , vesicle , chemistry , thermodynamics , organic chemistry , membrane , physics , computer science , engineering , programming language , biochemistry
Shear‐induced microstructural transitions in aqueous systems of a cationic commercial esterquat‐type surfactant used in concentrated fabric softeners were rheologically and microscopically characterized. Binary (surfactant/water) and ternary (surfactant/CaCl 2 /water) systems were studied. The obtained flow curves demonstrated the shear‐thickening behavior in ternary systems at high shear rates, provoked by shear‐induced transitions from surfactant bilayers to multilamellar vesicles. This fact was confirmed by hysteresis‐loop experiments which proved that a critical shear rate was required to observe apparent antithixotropic behavior in the ternary systems. Start‐up flow tests indicated that the increase of shear stress with shear time was more marked as the shear rate was increased. Finally, a comparative aging study of ternary systems with a surfactant used in concentrated fabric softeners and the ternary systems with a surfactant utilized in diluted and semiconcentrated fabric softeners was performed.