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RG Cain

Publications and source records attributed to RG Cain.

2 recordsLinked to original sources

Force Calibration in Lateral Force Microscopy.

An analysis of the contact mechanics and the forces of interaction in lateral force microscopy measurements is presented. This analysis allows for a new method of interpretation of the frictional forces, the lateral contact stiffness, and the contact shear strength. The technique was developed for the interpretation of frictional data obtained with colloidal probes, although results are presented which illustrate its ability to interpret measurements recorded with both colloidal probes and standard atomic force microscopy tips. The technique is found to compensate for the variations in the contact geometry, giving repeatable results for probes of different sizes. A critical review of other techniques which have been employed to interpret the frictional force in lateral force microscopy is also presented. Copyright 2000 Academic Press.

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Microscopic and macroscopic effects of surface lubricant films in granular shear

Experiments were conducted to investigate the link between particle-particle interaction forces and the bulk properties of granular shear using an idealized system of near-spherical, monosized glass beads. The atomic force microscopy colloidal probe technique was employed to investigate the adhesion and friction between a single bead and a second glass surface, while the annular shear cell was used to measure the shear properties of the bulk granular material. A covalently bound monomolecular film of aliphatic chains was introduced to alter the tribological interactions between the particles. The atomic force microscope was used to measure the reduction in the particle-particle surface forces resulting from the addition of the boundary lubricant, while the shear cell showed that the effect of the lubricant film was to reduce the coefficient of internal friction and the dilation during shear. This is an experimental study to provide quantitative data linking particle-particle interaction forces and the shear properties of a granular body.

Journal Article↗