Solid Surfaces Adsorption and Desorption of Different Substances

6 SOLID SURFACES ADSORPTION AND DESORPTION (OF DIFFERENT SUBSTANCES) 

The differences between perfect crystal surfaces and surfaces with defects are very obvious in many everyday observations. The solids were the first material that were analyzed at molecular scale. This led to the understanding of the structures of solid substances and the crystal atomic structure. This is because while molecular structures of solids can be investigated by methods such as x-ray diffraction, the same analyses for liquids are not that straightforward. These analyses have also shown that surface defects at molecular level exist. 

FIGURE 1.41 Solid surface molecules (a) perfect crystal and (b) surface with defects. 

FIGURE 1.42 The surface force equilibrium between surface tensions of liquid (GL)-solid (GS)-liquid-solid (GLS)-contact angle (CA). 

Surface tension of solid (ys) = Surface tension of solid/liquid (Ysl) 

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