PROPAGATION OF PHOTOINDUCED SURFACE PRESSURE PERTURBATION ALONG A MIXED BENZOSPIROPYRAN-OCTADECANOL MONOLAYER

The state and the elastic dilatational properties of a mixed spiropyra n (with attached hydrocarbon)-octadecanol(1:5, mol/mol) spread monolay er was studied. A localized photochemical excitation was used to gener ate dilatational motion along the elastic monolayer. The surface press ure Variations at various distances from the photoexcited region were measured. The experimental results are in quantitative agreement with a theoretical model taking into account the rheological properties of the interface and the liquid substrate as well as the rate constant fo r the photochemical process.