Bangham and Razouk observed that as y0V represented the energy of a surface in contact with a saturated vapour of partial pressure p0, there must be present on the surface a film of condensed vapour with its own surface energy re0. The total surface energy of the solid is thus:

Substituting for y°V in eqn [10] gives:

The interfacial energy of the solid-liquid interface ySL, can also be expressed as the sum of the surface energies of the individual phases separately, where yS is the surface energy of the solid, and yLV is the surface energy of the liquid in contact with vapour, and wSLV is the work of adhesion which has to be subtracted:

Experimental characterization of hydrophobicity - contact angle Interfacial energies for liquids may be measured by surface tension, while those for solid-liquid interfaces may be inferred from contact angle measurements.

If a liquid is placed on a solid surface it will form a droplet (Figure 2). The droplet will have a definite angle of contact, 6, with the surface. The change in the free energy AG0 of the three-phase contact surface if the area of contact, AAS, between the droplet and the surface were to change slightly is:

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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