Sorción

Sorción is a general term encompassing the processes by which one substance takes up another substance into its bulk or onto its surface. This phenomenon can occur in various phases of matter, including solid, liquid, and gas. The term "sorción" is an umbrella term that covers both adsorption and absorption. Adsorption describes the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This creates a film of the sorbate (the substance being adsorbed) on the surface of the sorbent (the material that does the adsorbing). Absorption, on the other hand, involves the uptake of a substance into the bulk of another material, where the sorbate penetrates and becomes distributed throughout the sorbent.

The distinction between adsorption and absorption is crucial. In adsorption, the process is primarily a surface phenomenon, meaning the sorbate molecules or atoms accumulate on the outer or inner surfaces of the sorbent. In absorption, the sorbate diffuses into the internal structure of the sorbent and is distributed uniformly throughout its volume. In many real-world scenarios, both adsorption and absorption can occur simultaneously, making it difficult to differentiate between them without specific experimental analysis.

Sorptive processes have numerous applications in science and technology. They are fundamental to processes like chromatography, where separation is achieved based on differential adsorption or absorption. Filtration systems often utilize sorbent materials to remove impurities from air or water. Catalysis frequently relies on adsorption of reactants onto the catalyst surface to facilitate chemical reactions. Furthermore, sorptive phenomena play a role in biological systems, such as the absorption of nutrients in the digestive system or the adsorption of neurotransmitters onto receptor sites. Understanding the principles of sorción is therefore essential in fields ranging from environmental engineering and chemical processing to medicine and materials science.