Nanoparticle transport models in confined fluids

T.S. Mahadevan, M. Kojic, M. Milosevic, V. Isailovic, N. Filipovic, M. Ferrari, A. Ziemys
The Methodist Hospital Research Institute, US

Keywords: nanoparticle, microparticle, diffusion, flow, nanopore

Summary:

Mechanisms of nanoparticle (NP) and microparticle (MP) transport in confined spaces and role of material properties are not clearly understood, and transport models may not be complete. Here we present recently developed models of convective particle transport of MPs and diffusion transport of NPs in confining dimensions comparable to particle size. In studying MP and NP convective motion our focus is on particle shape effects on trajectories in small channels with shear. Results show circular and elliptical nanoparticles flow similarly, while rotations differ significantly. NP diffusion was studied from a reservoir into nanopores through a mesoscale model, where NP interactions are based on colloids. Ballistic, first-order and pseudo zero-order transport regimes are predicted for fixed NP size and different nanopore dimensions. We found that transport regimes and NP penetration depth are modulated by the energy barrier at nanopores entrance, which may change by 6 orders of magnitude. The NP transport results confirmed experimentally established findings, and suggest an explanation of unexpected NP transport behavior. Our models are dedicated to help designing and optimizing transport processes and fluidic devices in areas of filtration, cooling, fluid and particle handling, novel therapeutics and energy transfer.