PHOTOMODULATION OF TRANSPORT RATES IN LIQUID MEMBRANES CONTAINING PHOTOACTIVE CARRIERS

A steady-state model describing photofacilitated transport in liquid m embranes is used to consider photoactive carriers with a wide range of thermodynamic and kinetic properties in order to calculate photoinduc ed modulation in the transport rates of solutes, a phenomenon known as photomodulation, Most experimental and theoretical studies have focus ed on systems in which strongly binding forms of the carrier and carri er-solute complex absorb light to convert to weakly binding forms. For such systems, absorption of light can cause-photomodulation increases up to a factor of 3. However, the maximum photoefficiencies are only a few percent, where photoefficiency is defined as the difference betw een the flux under illumination and in the dark. divided by the incide nt photon flux. Conversely, if the weakly binding forms of the carrier and complex are photoactive. photomodulation increases of a factor of 20 can be achieved, along with photoefficiencies well over 10%. This study provides guidelines for the selection of carriers for future exp erimental investigations of photofacilitated liquid membranes.