Photochromic Langmuir-Blodgett multilayers as photoactive coatings

The opportunity to exploit the light-induced switching of photochromic systems to develop photoactive coatings is considered. Using a bottom-up approach as Langmuir-Blodgett (LB) technique we realize a monomolecular up to tens layers coating. In order to effectively apply LB technique a proper class of diarylethene-based amphipilic materials are designed and synthesized through an optimized synthetic route. Photochromism both of the solution and of the active coating is characterized. The molecular design of these molecules is effective in promoting the formation of the Langmuir monolayer on water sub-phase, whose quality depends on the isomeric form the switching material is deposited. According to the character of the substrate and the number of multilayer deposited a tunable change in the final system wettability is obtained.