Читать книгу Adhesives for Wood and Lignocellulosic Materials - R. N. Kumar - Страница 64

For spreading, another parameter, the spreading coefficient γ_SV – γ_SL – γ_LV appears to be important in classifying liquids that have a tendency to form good films on a given substrate. In general, the larger and more positive value of the spreading coefficient (S), the more energy is gained by intercalating a liquid film between a solid and air. Thus,

S > 0, spontaneous spreading

S > 0, not spontaneous spreading

Though the condition S > 0 is necessary for a liquid to spread spontaneously on a solid, it is insufficient to describe the final state of the film.