IMR: Aquisition of a Stress Rheometer for Polymer Materials Research and Education

Northwestern University, Evanston IL

Investigators

Abstract

This is an award from the Instrumentation for Materials Research program in DMR to Northwestern University. The award is for the acquisition of a controlled stress rheometer to support a wide array of research at Northwestern University on polymer materials and other complex fluids. The proposed instrument will be housed in a central polymer characterization facility, replacing aging equipment with limited capabilities. In addition, it will provide entirely new capabilities for controlled stress testing (such as creep/recovery experiments) that have never been available to the Northwestern community, and that are of significant potential value for the classes of materials under study by the major users of the instrument. In addition to its use in research, the instrument will be used extensively for lab experiments and student projects in a regularly scheduled course on polymer viscoelasticity and flow. The instrument will serve the diverse needs of several faculty members who are presently pursuing research projects that require extensive rheological testing. These include (i) studies of flow-induced structural changes in ordered polymeric and surfactant fluids; (ii) studies of block-copolymer gels that provide a matrix for highly filled gel systems with applications in ceramic processing; (iii) thermoresponsive polymer solutions and microgels under development as matrices for advanced biopolymer separations in microchannel devices; and (iv) a variety of functionalized polymer gels and networks for biomaterials applications. In addition to the primary user community, there are several other Northwestern faculty members who are likely to take advantage of this facility intermittently for miscellaneous polymer & fluid characterization needs. %%% This award from the Instrumentation for Materials Research program in DMR supports the acquisition of a rheometer at Northwestern University. 'Rheology' is the study of the flow properties of so-called complex fluids, and the primary instrumentation used for such research are rheometers, which measure the flow behavior of such complicated materials under well-defined conditions. Many technologically important materials defy simple classification as either solids or liquids. Instead, their flow properties are more complicated, frequently combining elements of both solid and liquid character. Familiar examples from everyday life include food products such as egg whites or mayonnaise, consumer products such as toothpaste, lotions, and adhesives, and biological fluids. The new rheometer will serve a broad community of materials researchers at Northwestern University. Some areas of research that will benefit from this new instrumentation include: 1. Studies of flow-induced structural changes in ordered polymeric and surfactant fluids. 2. Studies of block-copolymer gels that provide a matrix for highly filled gel systems with applications in ceramic processing. 3. Thermoresponsive polymer solutions and microgels under development as matrices for advanced biopolymer separations in microchannel devices. 4. Functionalized polymer gels and networks for biomaterials applications. New materials for tissue engineering and drug delivery are being synthesized with 'bio-mimetic' approaches-designed to simulated nature's strategies for gel and network formation.