Anomalous Enhancement of Interphase Transport Rates by Nanoparticles: Effect of Magnetic Iron Oxide on Gas−Liquid Mass Transfer

Abstract

In this paper, we examine the effect of magnetic iron oxide nanoparticles on gas−liquid mass transfer rates. Carbon dioxide and oxygen are the gases absorbed, into a variety of reactive and nonreactive liquids. Experiments have been carried out in a wetted wall column (where the hydrodynamics can be rigorously modeled) and in a capillary tube (with the liquid phase being quiescent). In the case of absorption with reaction, studies have been conducted in several absorption regimes, representing different levels of transport limitations. The experiments convincingly demonstrate that the liquid phase mass transfer coefficients are significantly enhanced in the presence of nanoparticles in the region of concentration gradients, the extent of enhancement depending on the volume fraction of solid particles in the fluid, and on the particle size scaled with respect to the depth of penetration of the diffusing solute. A modified Sherwood number has been identified, based on the traditional theories of interphase ...