HaberleTV Comment: It is a fact that after a while newspaper clippings, paper document and books turn yellow;however, the reason of this issue can not be known widely. For more details read the text…
The Oxygen Is Remarkable
It’s important that paper is made from components that yellow over time. According to Susan Richardson, a chemistry professor at the University of South Carolina the yellowish colour occurs when the components of paper are exposed to oxygen. Therefore, oxgyen is essential for this issue.
Natural Wood Component Called Lignin
It is an obvious situation that most paper is made from wood. Besides, these kind of woods largely consist of cellulose and a natural wood component called lignin that gives land plant cell walls their rigidity and makes wood very stiff and durable. According to experts, cellulose which is a colorless substance is remarkably good at reflecting light. This means that means we perceive it as being white. This is why paper is usually observed as white.
Lignin Is A Polymer
It is known that lignin is one of the most important polymer that when lignin is exposed to light and the surrounding air, its molecular structure changes. Besides, being polymer means that the construction of material is built from batches of the same molecular unit bonded together. From this point of view, for lignin repeating units are alcohols consisting of oxygen and hydrogen with a smattering of carbon atoms thrown in. Moreover, after oxidation procedure, oxygen molecules are added to lignin;therefore , chromophores (meaning “color bearers,” or “color carriers” in Greek) are occured throughout the structure of lignin. The parts of chromophores reflect certain wavelengths of light that our eyes perceive as color and the parts of books including lignin are observed as yellowish color.