Single Molecules Rock and Roll Near the Glass Transition

Glasses are widely used, from structural and optical materials to drug delivery, but the dynamics that lead to their formation are not well understood. In their Perspective, [Ediger and Skinner][1] highlight the study by [Deschenes and Vanden Bout][2], who have measured the reorientation dynamics of single dye molecules in a polymer near the glass transition temperature. They can see individual molecules reorient in real time and watch individual molecules reorient hundreds of times. The individual molecules have different rates and are observed to change their rates, confirming the importance of heterogeneous dynamics near the glass transition. [1]: http://www.sciencemag.org/cgi/content/full/292/5515/233 [2]: http://www.sciencemag.org/cgi/content/short/292/5515/255