The central theme of our research program derives from a desire to better understand the thermodynamics, dynamics, and structure-property relationships of polymers, polymer mixtures, and polymer solutions, with particular emphasis on systems containing block copolymers. Of primary interest is how molecular characteristics influence the thermodynamics and dynamics that lead to the observed morphologies and phase behavior and how this phase behavior in turn influences observed properties. To address these issues, three broad areas of expertise have been developed in the group: polymer synthesis, morphological characterization, and property evaluation.
The main goal of our synthetic efforts is to create model polymers of controlled molecular characteristics for thermodynamic analysis. Anionic polymerization represents the primary synthetic tool with which we control the molecular characteristics such as polymer molecular weight, molecular weight distribution, microstructure, and chain architecture. Techniques used for molecular characterization include NMR, size exclusion chromatography, and light scattering.
Characterization of morphology and phase behavior is accomplished through the use of various scattering and microscopy techniques. The group makes extensive use of small-angle neutron scattering (SANS) and small-angle synchrotron x-ray scattering (SAXS) at national facilities, along with X-ray and light scattering conducted in our laboratory. Complementary structural information is achieved through the use of various electron microscopy techniques including transmission electron microscopy (TEM) or scanning electron microscopy (SEM) for bulk samples and cryo-TEM or cryo-SEM for polymer solutions.
In addition to the molecular and morphological properties, many other properties are also frequently of interest. For example, polymer dynamics are investigated through rheological measurements and often correlate with phase state. Various mechanical properties (fracture toughness, modulus, etc) are also routinely measured to investigate how morphological and molecular properties impact mechanical properties.
This basic research program affects and is often inspired by a variety of technologically important fields, including polymer processing, composites, fracture mechanics, separations, microelectronics, and drug delivery. To learn more about topics currently under investigation by the group, please visit the group members or publications pages.