Direct measurement of forces between silica surfaces in aqueous CaCl2 solutions using an atomic force microscope

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Forces between a silica surface and a small silica particle, in aqueous CaCl2 solutions, have been measured using an atomic force microscope (AFM). This technique allows the measurement of forces between a surface and virtually any colloid particle of interest. In conditions where the surface coverage of Ca2+ was very low (low pH and low cation concentration), a short-range repulsion was measured, which appeared to be due to hydration of the surfaces. When Ca2+ ions were adsorbed onto the surface (high pH or high cation concentration), the force measured was always attractive and could be reasonably explained using DLVO theory.

Original languageEnglish
Pages (from-to)293-295
Number of pages3
JournalJournal of Colloid and Interface Science
Issue number1
Publication statusPublished - 1 Jan 1992
Externally publishedYes

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