Because the Peclet number is very small for nanofluidic systems, diffusion may be at least as important as the active mass transport. In nanoscale solid surfaces may alter fluid properties and diffusion at interface. Here, we computationally study confined interface phenomena and, using our recently developed novel multiscale (MD+FE) diffusion model, we present diffusive transport regime analysis. Results suggested that interface reduces diffusivity by strengthening hydration cage of diffusing molecules, and that Eyring equation could be used in rationalizing diffusivity at surfaces. Using acquired results from MD simulations, we studied parametrically the diffusive mass release through different size and length nanochannels. Novel parameters were established to determine the character of the diffusion regime and kinetics, while approaching nanochannel dimensions 3-4 sizes of the diffusing molecules new diffusion transport characteristics are established. The results are in agreement with experimental observations, and can serve for establishing conditions for the non-Fickian transport regime. New parameters have been introduced that can be of help in design and optimization of nanofluidic systems. The approach presented here can be of significant help in the areas such as drug delivery, design of sensors, as well as chemical and energy industries.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: June 18, 2012
Pages: 705 - 707
Industry sector: Advanced Materials & Manufacturing
Topics: Informatics, Modeling & Simulation