Structure of a lamellar phase formed by non-ionic surfactant and water - Effects of shear flow

We have investigated effects of shear flow on the structure of lamellar phase in hepta(oxyethylene glycol)-n-hexadecylether-water system using small-angle neutron scattering (SANS) under shear flow at the shear rates (gamma) from 10(-3) s(-1) to 50 s(-1). In the range (gamma) over dot=10(2)(-) similar to 1 s(-1), significant changes have been observed in both intensity and position of the reflection peak. Small-angle X-ray scattering without shear has been also measured at various concentrations and temperatures. It has been suggested from these results that the shear flow causes contraction of lamellar domains and formation of a new domain composed of disrupted bilayers which grows rapidly with increasing shear rate and reconstructs original microstructures.