Wettability characterization

Most suitable for the examination of the surface is x-ray photoelectron spectroscopy, whereas the wettability determination can be established by a detailed interpretation of core flooding experiments and wettability index measurements. The results of such studies show that the organic carbon content in the surface is well correlated with the wetting behavior of the material characterized by petrophysical measurements [1467,1468]. 

V. Gurau, M. J. Bluemle, E. S. De Castro, et al. Characterization of transport properties in gas diffusion layers for proton exchange membrane fuel cells. 1. Wettability (internal contact angle to water and surface energy of GDL fibers). Journal of Power Sources 160 (2006) 1156-1162. 

Lee, W.J., Seferis, J.C. and Berg, J.C. (1988). Characterizing high performance composite processability with dynamic fiber wettability measurements. Polym. Composites 9, 36-41. 

Another important property is the structure (see Section 4.1) which characterizes the coalescence of primary particles into aggregates resembling chains or bunches of grapes. The dibutyl phthalate (DBP) absorption is commonly accepted as a measure for the carbon black structure. Due to absorption phenomena the DBP number increases with increasing specific surface area. Oil absorption (or, in general, the vehicle demand) is as well an indicator for the structure, but it also depends on the wettability of the black surface. Since linseed oil is a polar system, oil absorption declines as the concentration of surface oxides rises. 

The next four chapters provide an introduction to the concepts and techniques needed to study and understand dispersion stability. Some approaches to the characterization of emulsions, foams and suspensions, and of their dispersed species (droplets, bubbles and particles)are described in Chapter 2. The concepts of surface tension, wettability and surface activity, which are important to the stability and properties of all types of dispersion, are described in Chapter 3. To this is added the nature of electrically charged surfaces in Chapter 4. All of these aspects are brought together in Chapter 5 in an introduction to the stability of dispersions. 

A number of studies have examined fibril formation in the presence of different solid nonbiological surfaces, as summarized in Table 1. While many of these studies have focused on the formation of fibrils, the wettability and RMS of some surfaces have been characterized. Typical surface contact angles are also presented in Table 1 to aid comparison between these surface-based experiments. 

Actually, it characterizes the effective wettability of. particles, i.e., the wettability under the actual operating conditions. 

The proposed models are functions of a hydrodynamic parameter Lm which characterizes the effective wettability of the particles. 

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