Soft Matter Seminar: From macro- to nanoscale: Optical Microscopy and Förster Resonance Energy Transfer (FRET) as tools for investigating the morphology of polymer nanocomposites

Friday, April 8, 2011 - 1:15pm - 2:30pm
Reiss 261A
Mauro Zammarano

The morphological characterization of polymer nanocomposites over multiple length scales is a fundamental challenge which must be addressed to enable a more complete understanding of the structure-processing-property relations governing such materials. Several techniques have been developed for characterizing the morphology of polymer nanocomposites, but none of them is a stand-alone method. The most widely used of these methods is TEM which requires time-consuming sample preparation (i.e., microtoming) and the acquisition of tens of micrographs and a statistical analysis of data to provide a representative view of nanocomposite structure.

In this talk a technique for high-throughput monitoring of interface and dispersion in polymer nanocomposites based on Förster resonance energy transfer (FRET) is presented. It is shown how LSCM can be combined with FRET analysis to visualize the interface through an easily accessible method that is amenable to high throughput material characterization. In principle, this approach contains both nano- and meso/macro-scale information. FRET is intrinsically a nanoscale interaction phenomenon and LSCM allows a three-dimensional visualization of the interface at a meso- and macroscale, simultaneously. Color-coded images are generated for a real-space observation of energy transfer efficiency, and reveal interface formation at a nanoscale while probing a macroscale area that is large enough to be representative of the entire sample. The unique ability of this technique to monitor the interface at a nanoscale, while providing orientation and spatial information at a meso- and macroscale, endows a new powerful tool for structure-property-processing investigation in polymer nanocomposites.

Host: Daniel Blair