A new class of photchromic materials has been developed by graduate student Travis DeJournett in Materials Science and Engineering at Johns Hopkins.  Based on a type of polymer matrix nanocomposite that is formed using an in situ, chemical vapor deposition process, DeJournett has successfully formed complicated nanoparticulate structures displaying photochromic behavior in fluorocarbon-based polymers.  TEM studies have revealed involved nanoparticle transformations that accompany the photochromic response.  The processing technique is highly scalable and can be used to make large sheets of photochromic material that can be used in energy saving applications where sun light needs to be blocked during the day.