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  What is chemiluminescence?

Project aims

Why does paper degrade?
How to prevent degradation
Paper stability estimation
What is chemiluminescence
CL and the cultural heritage

HE FACT THAT LIGHT can be emmited during a chemical reaction is well known to fireflies attracting each other during summer nights. In their organs, light production is a consequence of a series of chemical reactions involving oxidation of a natural substance luciferin and an enzyme luciferase. In general, production of light during a chemical reaction, i.e. chemiluminescence, requires that during a reaction enough energy is released, leading to products in an energetically excited state. During relaxation to the ground state, photon (light particle) emission may occur. If efficiency of the process is high, light may be detected by the human eye, such as is the case of oxidation of luminol, schematically represented below.


Oxidation of Luminol


in the excited state

in the ground state


Luminol Solution

Luminol in solution prior to addition of the oxidant hydrogen peroxide (H2O2).



Evolution of chemiluminescence after addition of H2O2.


Of the vast number of oxidation reactions, very few lead to light intensities high enough to be seen by the naked eye. Sensitive cameras or even more sensitive light detectors (photomultipliers) must be used in order to see light emitted during oxidation of organic materials. It is estimated that of all the molecules produced during an oxidation reaction only 1 in 1,000,000,000 emits a photon, or even less. Since chemiluminescence accompanies oxidation reactions and since these represent an important aspect of cellulose degradation, the aim of PAPYLUM research team is to construct an appropriate instrument and to study light emission in order to learn more about the degradation processes.


Papylum. Anno MMII