Scaling and crossovers in molecular transport in nano-fluidic systems

A simple, analytically soluble model for transport in nanoconfined systems is presented here. The effect of confinement is introduced as a dependence of the solute diffusivity on the concentration, channel size, and intermolecular interactions. We apply the model to the description of molecule and nanoparticle release from devices consisting of slit-nanochannel membranes. We show that, in general, the cumulative amount of analyte released obeys a scaling form as a function of time. Additionally, the model is extended to more complicate situations in which the physico-chemical characteristics of membrane and solvent vary with time, and crossovers between different regimes appear.