IUPAC

To recommend:

• Procedures for the measurement of the interparticle distance dependence of colloidal force data using the atomic force microscope colloid probe technique
• Methods by which the force-distance data can be compared with existing models of interparticle forces.

The colloid probe AFM technique is a promising new method to determine the interactions between colloidal bodies. The technique is based on the general AFM and this equipment is, in principle, available for many research groups (not excessively expensive). In order to avoid confusion in the literature about the use of the AFM equipment for colloid stability measurements (and consequently about the interpretation of results) recommendations for the use of this equipment for this type of measurement are needed.

Project Contents:

• Principles of atomic force microscopy
• Attachment of colloidal probe to cantilever
• Force measurement
• Distance separation
• Determination of spring constant
• Determination of colloid probe radius
• Interaction geometry
• Interparticle forces
• Non-deformable and deformable surfaces
• Symmetric and asymmetric interactions

Review/update published in Chem. Int. Nov 2003In July 2004, a technical report was submitted for publication in Pure and Applied Chemistry.

December 2005 - project completed - IUPAC Technical Report in Pure Appl. Chem. 77(12), 2149-2170, 2005