Author
ROSENAU, THOMAS - University Of Natural Resources & Applied Life Sciences - Austria | |
POTTHAST, ANTJE - University Of Natural Resources & Applied Life Sciences - Austria | |
KRAINZ, KARIN - University Of Natural Resources & Applied Life Sciences - Austria | |
HETTEGGER, HUBERT - University Of Natural Resources & Applied Life Sciences - Austria | |
HENNIGES, UTE - University Of Natural Resources & Applied Life Sciences - Austria | |
YONEDA, YUKO - University Of Natural Resources & Applied Life Sciences - Austria | |
ROHRER, CHRISTIAN - Lohmann Animal Health | |
FRENCH, ALFRED - Retired ARS Employee |
Submitted to: Cellulose
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/5/2014 Publication Date: 7/1/2014 Citation: Rosenau, T., Potthast, A., Krainz, K., Hettegger, H., Henniges, U., Yoneda, Y., Rohrer, C., French, A. 2014. Chromophores in cellulosics, XI: isolation and identification of residual chromophores from bacterial cellulose. Cellulose. DOI 10.1007/s10570-014-0289-0. Interpretive Summary: Cotton or linen fabrics and paper, as well as other items composed chiefly of cellulose, tend to change to a yellow or brown color as they age. The change in color is usually accompanied by increased brittleness and loss of strength, as well. A cause of these phenomena is thought to be the formation of chemical compounds (chromophores) that originate in the individual glucose units of the cellulose which consists of many glucose residues connected together. In the present work, many aspects of the structure and chemistry of another important chromophore, 5,8-dihydroxy-[1,4]-napthoquinone are brought together along with new results from computational quantum mechanics studies to obtain new understanding of the various reaction mechanisms and potential ways to stop, or slow, the deterioration of items made from cellulose. Current attempts to change the color are by bleaching, for example, are largely futile because the benzoquinone structure is readily re-oxidized to the dihydroxy benzoquinone, a chromophore that is visible at the parts per billion level. Other chemical remedies are discussed. Technical Abstract: Cotton or linen fabrics and paper, as well as other items composed chiefly of cellulose, tend to change to a yellow or brown color as they age. The change in color is usually accompanied by increased brittleness and loss of strength, as well. A cause of these phenomena is thought to be the formation of chemical compounds (chromophores) that originate in the individual glucose units of the cellulose which consists of many glucose residues connected together. In the present work, many aspects of the structure and chemistry of another important chromophore, 5,8-dihydroxy-[1,4]-napthoquinone are brought together along with new results from computational quantum mechanics studies to obtain new understanding of the various reaction mechanisms and potential ways to stop, or slow, the deterioration of items made from cellulose. Current attempts to change the color are by bleaching, for example, are largely futile because the benzoquinone structure is readily re-oxidized to the dihydroxy benzoquinone, a chromophore that is visible at the parts per billion level. Other chemical remedies are discussed. |