FIG. 32 Scanning laser microscopic reflection features of pseudoemulsion films from the model foaming solution (60 mM SDS/0.5 wt.% PVA) for the silicone oil antifoams (A series) and the mixed-type antifoams (B series). Estimated images of vertical sectional views are shown under these features.

Fig. 33 illustrates the SLM reflection features of the pseudoemulsion films from the model foaming solution formed on the top of the hydrophobic silica antifoams (C series) and the silicone resin antifoams (D series). Estimated images of the vertical sectional views are also shown under these SLM features. It is seen that the pseudoemulsion films were confirmed on the top of their particles when the thickness of the surfactant solutions was slightly

thinner than the diameter of the antifoam particles (C-1, D-1). Considerable differences in the features appeared as the drainage of the solution progressed. In the case of the hydrophobic silica particles, the pseudoemulsion film completely surrounded the particles with drainage and the film persisted until the film thickness became less than 0.1 µm (C2). The foam film rupture occurred on the surface of the particles after the removal of most of the surfactant solution (C-3). On the other hand, when the liquid film thickness decreased and became slightly less than the diameter of the silicone resin particles, the acute top of solid particles distorted the pseudoemulsion film. As soon as the distortion took place on the top of the antifoam droplet, the pseudoemulsion film can be momentarily ruptured and part of the particle appeared from the liquid film (D-2: surrounded by the white line). The surface of the particle gradually appeared depending on the thinning of the liquid film. These results clearly show that the rupture of the pseudoemulsion film was caused at the acute top of the silicone resin antifoam although instantaneous rupture did not occur as in the mixed-type antifoam.