Photochromic Nanoparticles

Bill Brittain
Texas State University, San Marcos
November 29, 2012
Duke University, Schiciano A | 4:30pm

The modification of inorganic nanoparticles with covalently attached soft materials is a commonly investigated hybrid system.   The modification of silica nanoparticles with polymers is frequently performed using “click” chemistry and/or living radical polymerization techniques.  The methodology will be described and examples of hybrid systems with active functionalities presented.  Recent results on nanoparticles modified with light sensitive molecules have demonstrated reverse photochromism.  We have studied the spiropyran-merocyanine rearrangement for molecules immobilized on silica.  Spiropyran is a frequently studied system but there are issues of degradation and the rates of coloration/decoloration.  We have also designed and synthesized a new photochromic system based on a tetrahydrochromeno structure.  Solution studies of this new photochrome will be compared to analogous systems already known in the literature.