0

Full Content is available to subscribers

Subscribe/Learn More  >

Extended Near Wall Hindered Diffusion Theory for Nanoparticles Under Short and Long Range Interactions

[+] Author Affiliations
Suchi Subhra Mukherji, Arindam Banerjee

Missouri University of Science and Technology, Rolla, MO

Paper No. IMECE2009-11116, pp. 407-416; 10 pages
doi:10.1115/IMECE2009-11116
From:
  • ASME 2009 International Mechanical Engineering Congress and Exposition
  • Volume 9: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B and C
  • Lake Buena Vista, Florida, USA, November 13–19, 2009
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-4382-6 | eISBN: 978-0-7918-3863-1
  • Copyright © 2009 by ASME

abstract

An extension of the near wall hindered diffusion theory of Brenner [1] is considered for spherical nano-particles undergoing Brownian motion under the influence of hydrodynamic drag and electrostatic interactions. Brenner’s theory is based on hydrodynamic interactions between a levitating particle and the wall and does not consider short range interactions (like electrostatic force and van der Waals force). Recent experiments by Banerjee & Kihm [2] (henceforth referred to as BK05), with nano-particles of radii ≤ 500 nm show substantial discrepancy between the experimental and theoretical values of normal reduction coefficient (ratio of near wall normal diffusivity to bulk diffusivity). However, the experimentally measured lateral reduction coefficient (ratio of tangential diffusivity of the wall to bulk diffusivity) show good agreement with theory. It is conjectured that the absence of short range interactions become critical for particle radii ≤ 500 nm in the (sub-micron) near wall region. The current work extends Brenner’s analytical theory (henceforth referred to as B61) considering various short and long range interactions. An analytical expression is derived for hindered diffusivity of a particle normal to the wall under the influence of hydrodynamic drag and electrostatic interaction with a constant surface charge density. The theory is validated with experiments of BK05 and shows a better agreement with measured values of diffusion coefficients for particles of radii 50 and 100 nm. The dependence of electrolyte concentrations on electrostatic potential energy for spheres has also been studied. Increase in ionic strength of electrolyte concentration confirms the reduction of electrostatic potential energy for different sphere sizes. Electrostatic interaction has a significant contribution in overall potential energy of the sphere in sub-micron near wall region when wall and sphere surface charge potentials are increased.

Copyright © 2009 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In