Viscoelastic detergent solutions

Viscoelastic Detergent Solutions from Rodlike Micelles... 

The results show furthermore that the long time effects which are sometimes observed in viscoelastic detergent solutions are not connected to the network but are determined by kinetic processes in which the rods approach to their equilibrium lengths. 

Many surfactant solutions are normal Newtonian liquids even up to rather high concentrations. Their viscosities are very small as compared with the viscosity of the solvent water. This is particulary the case for micellar solutions with concentrations up to 20% W/W in which spherical micelles are present. Even in the presence of rodlike micelles the viscosities can be rather low. Systems with rodlike micelles have recently been studied extensively. Missel et al. (1-2) studied alkylsulfate solutions and showed how the lengths of the rods can be varied by the addition of salt or by the detergent concentration. Under all these conditions the solutions are of rather low viscosity. On the other hand, we have studied a number of cationic detergent solutions in which rodlike micelles were formed and which all became quite viscous at rather low concentrations. In addition some of these solutions had elastic properties. The phenomenon of viscoelasticity in detergent solutions is not new. Exten-... 

Shikata T, Hirata H, Takatori E, OsaM K (1988a) Nonlinear viscoelastic behavior of aqueous detergent solutions. J Non-Newt Fluid Mech 28(2) 171-182... 

As soon as the rotational volumes of the rods begin to overlap, the viscosity increases abruptly several orders of magnitude within a very small concentration range. At high concentrations even the unstirred solutions are viscoelastic. The onset of the elasticity occurs at a rather well defined concentration c. For the detergent sy-... 

Gravsholt, S., Viscoelasticity in highly dilute aqueous solutions of pure cationic detergents, J. Colloid Interface ScL, 57, 575-577 (1976). 

Shikata T, Hirata K, Kotaka T (1987) Micelle formation of detergent molecules in aqueous media. 1. viscoelastic properties of aqueous cetyltrimethylammonium bromide solutions. Langmuir 3 1081-1086... 

---