(440d) 4D Rheo-SANS: A Novel Sample Environment for Soft Matter and Biological Materials Processing

Designing soft materials for specific functionalities is critical to scientific and industrial communities. Moreover, to realize a successful consumer product often requires materials processing with a complex thermal and shear history to create a specific nano/microstructure so with essential characteristics. Some important biological processes are also affected or even triggered by a shear flow. In this regard, effectively measuring the shear deformation of the structure using scattering techniques simultaneously with accurate mechanical measurements of shear stress is necessary. Importantly, the symmetry of the material breaks under shear and the scattering patterns from three independent shear planes (flow-velocity gradient, flow-vorticity, and velocity gradient-vorticity planes) are required to fully characterize the material structure. However, the current level of instrumentation lacks the capability of studying all three planes with rheological properties in one sample environment.

We demonstrate a novel sample environment to measure the 3D structure with enhanced time resolution in all three planes simultaneously with rheology, thereby creating a 4D measurement for structure-property determination in complex fluids and soft matter. Newtonian and complex fluids (glycerol, xanthan gum, and worm-like micelle CPCl/NaSal) are used to validate the instrumentation. Large- and small-amplitude oscillation and steady shear measurements are performed and validated against existing instrumentation. With this breakthrough, connecting the full structure for all shear planes to the non-linear mechanical responses can be realized and this can further benefit greatly in the research and development process for both scientific and industrial communities.