RheoSurfR – Neutron Reflectivity-Rheology Sample Environment for Studying Soft Matter, Biology and Materials Processing at Air-Liquid and Liquid-Liquid Interfaces

Academic and industrial researchers worldwide have a critical unmet scientific need for simultaneous measurement of surface moduli, both shear and bulk, and molecular structure, both in plane and through the interface, across a range of interfaces, area per molecule, and sample preparation. Neither DOE neutron scattering user facilities nor international facilities offer such a sample environment on neutron reflectometers necessary for the scientific community to develop molecular structure-property relationships for complex fluid interfaces. We propose to develop a world-leading sample environment for neutron reflectometry and integrate complementary characterization techniques such as interfacial rheology, Brewster angle microscopy and particle image velocimetry. Utilizing these techniques will enable the complete characterization of complex interfaces on all length scales (Ångstrom- nano-micro-macro) alongside surface moduli measurements that enables elucidation of novel molecular structure-property relationships at interfaces. A minimum viable protype was successfully designed and constructed. A quad- motor system with software to control interfacial deformation was designed and validated. Further, a neutron transparent band for interface containment and control was engineered to permit simultaneous interfacial rheological and neutron reflectivity measurements. Control over sample thermodynamic state has been demonstrated using a stable, fast-responding environmental chamber. Finally, commercialization paths and potential customers were identified for rapid commercialization after Phase II. The Phase I RheoSurfRTM prototype will be improved upon to optimize performance and minimize costs and complexity. Control systems will be improved and simplified, while maintaining high- level accuracy and precision. Complementary interfacial characterization capabilities will be added. Recommended experimental protocols will be established, control software will be finalized, and a final, commercial product will be brought to market. The sample environment will be deployable worldwide on neutron and X-ray reflectometry beamlines. Additionally, its unique interfacial rheology capabilities will make it desirable for use in both academic and industrial laboratories. The RheoSurfRTM sample environment addresses a substantial need of the neutron scattering user community and significantly improves the nation’s scientific infrastructure through new measurement capabilities along with efficiency benefits that maximize the scientific utility of valuable beamtime. Improved understanding of interfacial science is highly relevant to development of biomedical, advanced clean energy, and other nanotechnology- based products.