The influence of surface roughness

The roughness of the substrate surface may also influence the kinetics of wetting. 

Secondly, de Bruyne [138] has modelled various types of substrate surface topography and obtained quantitative expressions for the relationship between the extent of wetting and the driving pressure, taking any back pressure in the case of closed pores into account. For a closed cylindrical pore the depth of penetration, /p, is given by  

the extent of penetration, /p, is proportional to the square root of time. Also, this equation reveals that the penetration will increase as the viscosity of the adhesive is decreased, as the adhesive surface free energy is increased and as its contact angle approaches zero. Obviously, these last two requirements 

As commented by Packham [139], with a polymeric adhesive, evaporation from the liquid might well be slow, thus preventing the formation of a fully 

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Experiments were conducted with air through micro-channel A = 319 (friction factor. The relative surface roughness was low k /H = 0.001) and Kn < 0.001, thus the experiments were effectively isolated from the influence of surface roughness and rarefaction. The local friction factor is plotted versus Ma in Fig. 2.25 for air. The experimental A increases about 8% above the theoretical A as Ma increases to 0.35. 

The influence of surface roughness, surface diffusion of metal atoms, and exchange current density of the Cd(II)/Cd... 

A useful discussion of incompressible fluid flow in pipes and the influence of surface roughness and friction factors on pumping is found in Perry s Chemical Engineer s Handbook (49). 

With respect to the preparation of die surface, a measurement of a surface property is obviously only as good as the preparation of the surface on which the measurement is made. Ideally one would desire to have a surface which was atomically flat on a crystallographically perfect and chemically pure crystal. After reliable information had been obtained chi such ideal surfaces, it would then be necessary to determine the influence of surface roughness, of impurities, and of crystal imperfections of various kinds on the oxidation process. Most of the measurements to be described in this paper, however, have been made on surfaces which were prepared by the best methods available at this time. A convenient method of determining the important faces of a metal for detailed study involves the initial use of the specimen in the form of a sphere exposing all possible crystal faces such methods have been previously described, it should be emphasized that much additional work... 

Figure 66(a) describes the influence of surface roughness, represented by r (abscissa), on the attraction force A for different adhesion mechanisms. 

S. Anderson and E. Salas-Russo, The influence of surface roughness and oil viscosity on the transition in mixed lubricated sliding steel contacts, Wear, 174, 71-79, 1994. 

Fig. 10.6 Model sketches depicting the influence of surface roughness on the approach of particles to each other (left) and wetting (liquid bridge formation, right). The crosshatched area is the actual...

M. Quirynen, C.M.L. Bollen, The influence of surface roughness and surface-free energy on supra- and subgingival plaque formation in man. A review of the literature, J. Clin. Periodontol. 22 (1995) 1-14. 

As has been pointed out several times, the surface of paper is far from being a smooth ideal surface. This has great consequences on the wetting behaviour that is observed. For random rough surfaces, the influence of surface roughness can be described by using Wenzel s equation ... 

Tanaka M, Komagata M, Tsukada M, Kamiya H. Fractal analysis of the influence of surface roughness of toner particles on their flow properties and adhesion behavior. Powder Technol 2008 186 1-8. 

Apparently N. A. Fuks [2] is correct in that the quantity r in Eq. (1.39) must not be considered the particle radius, but rather the radius of those sub-microscopic projections through which actual contact occurs between the particle and surface. Hence, in Chapter V we will be examining the influence of surface roughness and radius of curvature of the contacting bodies on the magnitude of adhesion. 

The influence of surface roughness on wetting has been discussed in detail in... 

First, let us examine in a qualitative manner, the influence of surface roughness on adhesion. Along this line, a study has been made of the adhesion of ideally smooth spherical glass particles to rough surfaces obtained by finishing steel and cast iron specimens to different classes of surface finish [156]. 

In order to evaluate the influence of surface roughness on adhesion, the con-... 

Formation and Properties of Organophos-phate SAMs onRough (SLA) Surfaces. The estimation of surface coverage and properties on rough surfaces, in comparison to the ideal smooth-surface case, is complicated by the influence of surface roughness on both the quantitative XPS intensities and the contact angles. 

De Levie R. The influence of surface roughness of solid electrodes on electrochemical measurements. Electrochim Acta 1965 10 113-130. 

Despite the limitations of the results presented here they do provide a useful assessment of the influence of surface roughness upon cam and follower lubrication. 

Fredrik Svahn, The influence of surface roughness on friction and wear of machine element coatings Wear, Vol.254, pp.1092-1098, 2003... 

Wenzel (see, for example, ref. (9)) was the first to discuss the influence of surface roughness on the apparent or macroscopic contact angle. He introduced a roughness... 

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