Rheo-small angle neutron scattering (rheo-SANS) methods combine microstructural SANS measurements with an applied deformation field in order to measure flow-induced structures in complex fluids. Such methods enable a robust characterization of the microstructure and flow properties of surfactant wormlike micelle (WLM) solutions. The development of new sample environments now enables the flow-induced microstructure to be measured in the three planes of shear: the flow-vorticity (1-3), flow-gradient (1-2), and gradient-vorticity (2-3) planes. Advances in neutron collection and data analysis have improved the temporal resolution of time-dependent responses, significantly reducing the time required to perform such measurements. Theoretical advances in constitutive modelling and the stress-SANS rule now permit the development and testing of structure-property relationships. Such methodologies have allowed flow instabilities, such as shear and vorticity banding, and shear-induced structural transitions to be identified in WLM solutions. Additional sample environments have enabled the study of WLMs under extensional and Poiseuille flows, in addition to flows in microfluidic devices.
|Original language||English (US)|
|Title of host publication||Non-wettable Surfaces|
|Subtitle of host publication||Theory, Preparation, and Applications|
|Editors||Cecile A. Dreiss, Yujun Feng|
|Publisher||Royal Society of Chemistry|
|Number of pages||43|
|ISBN (Electronic)||9781782621546, 9781782625162|
|State||Published - 2017|
|Name||RSC Soft Matter|
Bibliographical noteFunding Information:
The authors acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce, and the Institut Laue-Langevin in Grenoble, France in providing the neutron research facilities used in this work. This manuscript was prepared under cooperative agreement 70NANB12H239 from NIST, U.S. Department of Commerce. The statements, findings, conclusions and recommendations are those of the author(s) and do not necessarily reflect the view of NIST or the U.S. Department of Commerce.