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We used the atomic force microscope to determine the distributions of 150–200 nm diameter styrene-butadiene (SB) latex spheres with TR. = 45 °C deposited at sub monolayer coverages from water suspensions onto mica, glass, calcite and cellophane surfaces. Two deposition methods are used: drying of μl drops and dipping. For drop drying, the distributions are extremely inhomogeneous. A high density ring forms at the boundary of the area wet by the drop. At low suspension densities on cellophane, the ring is a close-packed monolayer several micrometers wide. Thicker rings form on calcite and glass. Inside the rings, the particle density is very low and non uniform; e.g., monolayer thick islands form on mica, short chains are predominant on calcite, small clusters form on glass, and isolated spheres occur on cellophane. Particle densities are substantially reduced near some substrate defects but are enhanced near others. For the dipping method, homogeneous distributions are obtained on glass and cellophane. The density of adsorbed particles increases linearly with immersion time and the distribution of monomers, dimers, and trimers is not characteristic of random adsorption.

We have constructed an inexpensive sample mounting stage for studies of temperature dependent processes in a surface force microscope (SFM). The stage is constructed from a Peltier thermoelectric heater secured to a standard SFM mounting stage with silver paint. The sample temperature can be varied from room temperature to about 100°C thus making it possible to use the SFM to observe thermally activated processes at lateral spatial resolutions of 10-20 nm. Approximately 10 minutes is required to reach thermal equilibrium following a 5°C temperature change. The lateral magnification must be calibrated at each temperature. We illustrate the capabilities of the stage with images of polystyrene spheres just below their glass transition temperature of 100°C.