Fotochimic

Fotochimic is a term that refers to the chemical reactions that are initiated by light. This phenomenon is fundamental to many natural processes and technological applications. In essence, when photons of light strike a molecule, they can transfer energy, causing electrons to become excited. This excited state can then lead to a variety of chemical transformations, such as bond breaking, bond formation, or rearrangement of atoms.

One of the most well-known examples of fotochimic reactions in nature is photosynthesis, the process by which plants convert light energy into chemical energy in the form of glucose. In this process, chlorophyll molecules absorb sunlight, initiating a series of reactions that split water and convert carbon dioxide into sugars. Another example is the photodegradation of materials, where exposure to sunlight can cause plastics, dyes, and other substances to break down over time.

Fotochimic principles are also harnessed in numerous human-made technologies. Photography itself relies on fotochimic reactions, where light-sensitive materials like silver halides undergo chemical changes when exposed to light to form an image. UV curing, used to harden inks, coatings, and adhesives rapidly, is another important application. The production of vitamin D in the skin upon exposure to sunlight is also a biological fotochimic process. Understanding and controlling fotochimic reactions allows for the development of new materials and more efficient processes.