Colloidal fibers as structurant for worm-like micellar solutions
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We investigate the rheological properties of a simplified version of a liquid detergent composed of an aqueous solution of the linear alkylbenzene sulphonate (LAS) surfactant, in which a small amount of fibers made of hydrogenated castor oil (HCO) is dispersed. At the concentration typically used in detergents, LAS is in a worm-like micellar phase exhibiting a Maxwellian behavior. The presence of HCO fibers provides elastic properties, such that the system behaves as a simple Zener body, mechanically characterized by a parallel connection of a spring and a Maxwell element. Despite this apparent independence of the contributions of the fibers and the surfactant medium to the mechanical characteristics of the system, we find that the low frequency modulus increases with increasing LAS concentration. This indicates that LAS induces attractive interactions among the HCO fibers, resulting in the formation of a stress-bearing structure that withstands shear at HCO concentrations, where the HCO fibers in the absence of attractive interactions would not sufficiently overlap to provide stress-bearing properties to the system.
KeywordsColloidal fiber Gel Depletion Worm-like micelle Rheology
We thank P&G for the materials and for financial support to G.Z. and S.M..
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 1.Larson RG (1999) The structure and rheology of complex fluids. Oxford University Press, New YorkGoogle Scholar
- 5.Gardel ML, Shin JH, MacKintosh FC, Mahadevan L, Matsudaira PA, Weitz DA (2014) Scaling of F-actin network rheology to probe single filament elasticity and dynamics. Phys Rev Lett 93:188102-1-188102-4Google Scholar
- 11.Derjaguin B, Landau L (1941) Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solution of electrolytes. Acta Physicochim 14:633–662Google Scholar
- 15.Yang D, Hrymak AN (2013) Rheology of aqueous dispersions of hydrogenated castor oil. Appl Rheol 23:23622-1-23622-9Google Scholar
- 26.Doi M, Edwards SF (1986) The theory of polymer dynamics. Clarendon Press, OxfordGoogle Scholar