Atomic force microscope study of the rejection of colloids by membrane pores

Nidal Hilal, W. Richard Bowen

Research output: Contribution to journalArticle

27 Citations (Scopus)


An atomic force microscope (AFM) in conjunction with the colloid probe technique has been used to study the electrical double layer interactions between a 0.75 μm) silica sphere and a polymeric microfiltration track etch Cyclopore membrane (nominally 1 μm) in aqueous solutions. The silica colloid probe was used to image the membrane surface (using the double layer mode) at different imaging forces in high purity water and at constant imaging force in sodium chloride solutions of different ionic strengths at pH 8. Force-distance measurements show clearly how the sphere detects the membrane surface. Quality of images produced from scanning the 0.75 μm silica particle across the surface deteriorates with increasing distance between the silica sphere and membrane surface. Such images were compared with those obtained from scanning a sharp silicon nitride tip over the membrane surface.

Original languageEnglish
Pages (from-to)289-295
Number of pages7
Issue number3
Publication statusPublished - 10 Nov 2002
Externally publishedYes



  • Atomic force microscopy
  • Colloid probe
  • Electrical double layer
  • Membrane
  • Microfiltration
  • Surface forces

ASJC Scopus subject areas

  • Filtration and Separation

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