Grant: Research Tools and Instruments - Category 1 (<$150,000)

Surface Forces Apparatus (SFA) is a research instrument for directly measuring the static and dynamic forces between surfaces, and for studying interfacial and thin film phenomena at the molecular level. The Surface Forces Apparatus 3 (SFA 3) requested in this proposal is the extremely stable and versatile apparatus among the SFA family. Useful for both basic and applied studies, the SFA 3 is an extremely sensitive instrument, and it measures the forces between two surfaces in vapors or liquids with a sensitivity of 10 nN and a distance resolution of 1§ measured in situ. It can also be used to measure surface deformations arising from surface forces, dynamic interactions such as viscoelastic and frictional forces, and other time-dependent phenomena in real time, etc. The Surface Forces Apparatus 3 (SFA 3) requested will be used by graduate students and researchers to conduct pioneering research to resolve a wide range of long-unresolved problems in many fields. These include intersurface forces and interaction dyanmics of viscoelastic/viscous polymer thin films in vapors and liquids, hydrophobic interactions in oil emulsions and colloids, specific ligand-receptor interactions in bioengineering for biodiagnostic devices and for drug and gene delivery applications, as well as interfacial effects and interactions in multiphase fluid systems. The award of this request for an SFA 3, coupled with our existing single molecular force spectroscopy and attenuated total internal reflection Fourier transform infrared spectroscopy, will enable us to conduct pioneering research on intermolecular and surface interactions of many soft materials and complex fluid systems. The success of the projects outlined in this proposal will have a significant socio-economical impact on Canadian chemical and mining industry and bioengineering, and place us among the world's best facilities in colloidal and interfacial sciences.