Interfacial response of a fluorescent dye grafted to glass

The properties of an epoxy/glass interfacial region are studied by covalent ly grafting a fluorescent probe to the glass surface. A dimethylaminonitros tilbene fluorophore is tethered to a triethoxysilane-coupling agent, genera ting a fluorescently labeled silane coupling agent (FLSCA). The glass surfa ce is coated with a silane layer that was doped with small amounts of FLSCA . When the FLSCA-doped, silane-coated glass is immersed in epoxy resin, a 4 2-nm blue shift in fluorescence occurs during resin cure over the grafted F LSCA layer. When the dye is dissolved in bulk epoxy a 64-nm blue shift occu rs during resin cure. The difference in blue shift is attributed to higher polarity and enhanced mobility in the buried interface.