205 DuPont Hall
Research in Dr. Mackay`s group is centered on two phenomena-dispersion of nanoparticles in polymeric materials and segregation of them from the same polymer when they are in a thin film. As it turns out, a surface introduces extra forces to the thermodynamics controlling miscibility and fine tuning the surface versus bulk phenomena allows assembly to the air interface or to the solid substrate supporting the film; of course, in a thick film, bulk phenomena occur.
Nanoparticle segregation in thin films is useful for energy applications, in particular, in the manufacture of organic-based solar cells. By controlling the segregation, or really self-assembly, solar cells can be manufactured cheaply and eventually on any substrate. However, to realize this type of device manufacture nanoscale characterization and the interaction of nanostructure development and processing conditions are critical. In Dr. Mackay`s group, many different characterization techniques to understand nanostructure-property correlations in thin polymer films used to make solar cells are used.
Dr. Mackay`s group is also interested in how nanoparticles affect the properties of bulk polymers. An initial discovery was that addition of nanoparticles to polymers can produce a viscosity decrease, a result at odds with Einstein`s original prediction that particles suspended in a liquid provides a viscosity increase. Furthermore, nanoparticle miscibility in polymers was found by the group to be very unusual and at odds with contemporary thought. We believe this phenomenon is dominated by the relative size of the nanoparticle and polymer molecule to create this and other unusual effects that have been observed.