When certain highly concentrated gels, such as silicic acid, are allowed to stand entirely undisturb — Surface Chemistry Chemistry Question
Question
When certain highly concentrated gels, such as silicic acid, are allowed to stand entirely undisturbed for an extended period, they uniquely undergo a structural phenomenon where they visibly shrink and spontaneously exude very small quantities of their trapped liquid continuous medium. What is the precise scientific terminology for this specific physical behavior?
💡 Solution & Explanation
The spontaneous exudation or macroscopic liberation of the trapped liquid medium from a static gel structure upon standing is specifically defined in colloid chemistry as syneresis or the "weeping" of gels. This phenomenon represents the physical and thermodynamic reverse of gel swelling.