Abstract
An atomic force microscope has been used to study the electrical double layer interactions between a silicon tip (with an oxidised surface) and two polymeric membranes, one microfiltration (nominally 0.1μm) and the other ultrafiltration (25,000 MWCO), in aqueous NaCl solutions. Force-distance curves were measured for the two membranes at four ionic strengths. The membranes were also imaged under the same conditions using electrical double layer repulsive forces of differing magnitudes - 'electrical double layer mode' imaging. Image analysis was used to determine surface pore size distributions. The force distance curves, together with numerically calculated potential profiles at the entrance to a charged pore, allow an explanation and identification of the optimum imaging conditions. The best images were obtained at high ionic strength with the tip close to the membrane.
Original language | English (US) |
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Pages (from-to) | 77-89 |
Number of pages | 13 |
Journal | Journal of Membrane Science |
Volume | 126 |
Issue number | 1 |
DOIs | |
State | Published - Apr 2 1997 |
Keywords
- Atomic force microscopy
- Electrical double layer
- Microfiltration
- Pore size distribution
- Surface forces
- Ultrafiltration
ASJC Scopus subject areas
- Biochemistry
- General Materials Science
- Physical and Theoretical Chemistry
- Filtration and Separation