Adhesion on Particle Shape and Surface Properties

Dependence of Adhesion on Particle Shape and Surface Properties 

Features of Adhesion of Cylindrical Particles and Other Regularly Shaped Particles. As in air, particle adhesion in liquid media has a number of special features when the particles are not spherical. First, let us consider the adhesion of particles to a glass surface in an aqueous medium when the particles are cylinders with a diameter of 40 fim and a length within the range of 100-600 jLim. The distribution of adherent particles with respect to adhesive force in a liquid medium, the same as in air (see Fig. V.l 1), follows a log-normal law [194]. 

On the basis of experimental data, let us find the parameters of the particle distribution with respect to adhesive force and then calculate the average force of adhesion by the use of Eq. (1.29). The results of these calculations, for cylindrical particles with a diameter of 40 im and various lengths on glass surfaces in an aqueous medium, are as follows  

The concepts developed previously relative to the log-normal distribution of adherent particles with respect to adhesive force can be used for the adhesion of cylindrical particles in a liquid medium. Studies of the adhesive forces of cylindrical particles have shown that the average force for such particles in air and with lengths of 100, 200, and 300 jum, is, respectively, 7.6 10, 15.6 10 , and 23.5 10 dyn, i.e., 15-20 times the average force of adhesion for these same particles in a liquid medium [160]. 

Still greater is the difference between the adhesion of cylindrical particles in air and in aqueous medium in the case of interaction with a rough steel surface having a Class 5 finish. The average force of adhesion of cylindrical particles with 

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