What is photo-oxidation reaction?

Photo-oxidation is a chain process incorporating a large number of chemical reactions which are subsequent to the outcome of the primary event—absorption of a photon, which induces breakdown to free-radical products.

What is photo oxidative degradation?

In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. Photo-oxidation causes the polymer chains to break (chain scission), resulting in the material becoming increasingly brittle.

What is oxidation in plastics?

Most polymers are subject to oxidation, and it is the most common form of plastic degradation (consider Table 2). Oxidation is a chemical reaction in which oxygen is introduced into the molecular structure of the polymer, creating a form of carbon-oxygen bonds known as carbonyl functionality.

What is photo-oxidation of water?

Photolysis is an oxidative process that means the splitting of water to form oxygen, protons and electrons in the presence of light. As a result, oxygen evolution happens and the electron travels to \[PS-II\]via the Mn-protein.

What is photo-oxidation of oil?

Photo-oxidation can change the composition of an oil. It occurs when the sun’s action on an oil slick causes oxygen and carbons to combine and form new products that may be resins. The resins may be somewhat soluble and dissolve into the water, or they may cause water-in-oil emulsions to form.

How can you prevent UV degradation?

There are several ways of avoiding UV degradation in plastics — by using stabilizers, absorbers or blockers. For many outdoor applications, the simple addition of carbon black at around a 2% level will provide the protection for the structure by the blocking process.

What is photo-oxidation or photolysis of water in light reaction?

In oxygenic photosynthesis, water (H2O) serves as a substrate for photolysis resulting in the generation of diatomic oxygen (O2). This is the process which returns oxygen to Earth’s atmosphere. Photolysis of water occurs in the thylakoids of cyanobacteria and the chloroplasts of green algae and plants.

What is photo-oxidation in biology?

Photo-oxidation means the release of electrons after absorption of a photon occurs during non-cyclic photophosphorylation. It involves an outsized number of chemical reactions. The oxidized CHL accepts an electron from the donor (H2O) and this leads to the synthesis of molecular oxygen from water.

What is photo-oxidation in plants?

species is termed photooxidative stress. This can occur in two ways: (1) the donation of energy or electrons directly to oxygen as a result of photosynthetic activity; (2) exposure of tissues to ultraviolet irradiation. Photoinhibition and photooxidation only usually occur when plants are exposed to stress.