UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Becker-Doring rate equations for heterogeneous nucleation, with direct vapour deposition and surface diffusion mechanisms
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Article
  • Authors:
    Kroon CMLV, Ford IJ
  • Publisher:
    ELSEVIER SCIENCE INC
  • Publication date:
    08/2011
  • Pagination:
    553, 561
  • Journal:
    ATMOS RES
  • Volume:
    101
  • Issue:
    3
  • Print ISSN:
    0169-8095
  • Language:
    EN
  • Keywords:
    Heterogeneous nucleation, Becker-Doring equations, Fletcher theory
  • Addresses:
    Kroon, CMLV
    UCL
    Dept Phys & Astron
    London
    WC1E 6BT
    England

    London Ctr Nanotechnol
    London
    WC1H 0AH
    England
Abstract
We develop a set of microscopic rate equations describing the growth and decay of molecular clusters adsorbed onto a seed particle. Such Becker-Daring equations are fundamental to descriptions of homogeneous nucleation, but do not appear to have been developed for the rather more complicated case of heterogeneous nucleation. We show that the familiar Fletcher theory of heterogeneous nucleation emerges from such a Becker-Daring description, but only if the concentration of adsorbed single molecules on the surface is estimated in a rather rudimentary manner. For small seed particles, this approach fails and one needs a proper Becker-Daring approach to provide a better estimate. The change in predicted nucleation rate can be several orders of magnitude for nanometre-size seed particles. We go on to include into the Becker-Daring treatment the processes of growth and decay of clusters by monomer surface diffusion on the seed. We use recent high quality experimental data to show that the latter process can make only a small contribution to the nucleation current for nanoparticle seeds. We also use the data to demonstrate that the traditional Fletcher theory fails to account for critical sizes and nucleation currents correctly, and that a modification to the implied underlying cluster properties is necessary. (C) 2011 Elsevier B.V. All rights reserved.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
Dept of Physics & Astronomy
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by