High-Temperature Behavior of Cellulose I
2011 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 115, no 10, 2155-2166 p.Article in journal (Refereed) Published
molecular simulation to elucidate the structural behavior of small hydrated cellulose I beta microfibrils heated to 227 degrees C (500 K) with two carbohydrate force fields. In contrast to the characteristic two-dimensional hydrogen-bonded layer sheets present in the cellulose I beta crystal structure, we show that at high temperature a three-dimensional hydrogen bond network forms, made possible by hydroxymethyl groups changing conformation from trans-gauche (TG) to gauche-gauche (GG) in every second layer corresponding to "center" chains in cellulose I beta and from TG to gauche-trans (GT) in the "origin" layer. The presence of a regular three-dimensional hydrogen bond network between neighboring sheets eliminates the possibility of twist, whereas two-dimensional hydrogen bonding allows for microfibril twist to occur. Structural features of this high-temperature phase as determined by molecular simulation may explain several experimental observations for which no detailed structural basis has been offered. This includes an explanation for the observed temperature and crystal size dependence for the extent of hydrogen/deuterium exchange, and diffraction patterns of cellulose at high temperature.
Place, publisher, year, edition, pages
2011. Vol. 115, no 10, 2155-2166 p.
SYNCHROTRON X-RAY; NEUTRON FIBER DIFFRACTION; TRANSMISSION ELECTRON-MICROSCOPY; DILUTE-ACID PRETREATMENT; HYDROGEN-BONDING SYSTEM; MAIZE CELL-WALLS; MOLECULAR-DYNAMICS; NATIVE CELLULOSE; CRYSTALLINE CELLULOSE; THERMAL-EXPANSION
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-31862DOI: 10.1021/jp1106839ISI: 000288113300004ScopusID: 2-s2.0-79952599185OAI: oai:DiVA.org:kth-31862DiVA: diva2:408338
QC 201104042011-04-042011-03-282014-04-11Bibliographically approved