Fotochémiques

Fotochémiques is a term that refers to photochemical reactions, which are chemical reactions initiated by the absorption of light. The word itself is a portmanteau of "foto" (Greek for light) and "chimique" (French for chemical). These reactions are fundamental to many natural and artificial processes.

In nature, photosynthesis is a prime example of a fotochémique process. Plants use sunlight to convert carbon dioxide and water into glucose (a sugar) and oxygen, providing energy for the plant and releasing oxygen into the atmosphere. Another natural example is the bleaching of pigments by sunlight, where the energy from light breaks down the chemical bonds responsible for color.

Artificial applications of fotochémiques are widespread. Photography, in its traditional film-based form, relies on light-sensitive silver halide crystals. When exposed to light, these crystals undergo photochemical changes, creating a latent image that can then be developed into a visible photograph. In industry, photoinitiators are used in UV curing processes, where light triggers a chemical reaction that hardens inks, coatings, and adhesives. Photopolymerization is another important industrial application, used in 3D printing and the manufacturing of various materials. The study of fotochémiques is crucial for understanding and developing new technologies in fields such as materials science, medicine, and energy.