Spatially Resolved Concentration and Segmental Flow Alignment in a Shear-Banding Solution of Polymer-Like Micelles

详细信息    查看全文

• 作者：A. Kate Gurnon ; Carlos L贸pez-Barr贸n ; Matthew J. Wasbrough ; Lionel Porcar ; Norman J. Wagner
• 刊名：ACS Macro Letters
• 出版年：2014
• 出版时间：March 18, 2014
• 年：2014
• 卷：3
• 期：3
• 页码：276-280
• 全文大小：316K
• 年卷期：v.3,no.3(March 18, 2014)
• ISSN：2161-1653

文摘

We measure the spatially resolved microstructure and concentration in the plane of flow for a viscoelastic solution of polymer-like micelles comprised of mass fraction 6.0% (volume fraction 6.6%) solution of 2:1 molar ratio cetylpyridinium chloride/sodium salicylate in 0.5 mol/L NaCl/D₂O through the shear banding transition. Spatially resolved flow small-angle neutron scattering measurements in the velocity鈥搗elocity gradient (1鈥?) plane of flow establish the local microstructure, and scanning narrow-aperture flow ultrasmall-angle neutron scattering (SNAFUSANS) measurements indicate no flow-induced concentration gradients within measurement accuracy. These results show shear banding in this solution is not associated with an isotropic鈥搉ematic transition and are fundamentally important for validating models of shear-banding complex fluids. Improvements in the SNAFUSANS method are also documented.