A molecular dynamics study of the thermal response of crystalline cellulose I beta
2011 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 18, no 2, 207-221 p.Article in journal (Refereed) Published
Molecular dynamics simulations were performed to better understand the atomic details of thermal induced transitions in cellulose I beta. The latest version of the GLYCAM force field series (GLYCAM06) was used for the simulations. The unit cell parameters, density, torsion angles and hydrogen-bonding network of the crystalline polymer were carefully analyzed. The simulated data were validated against the experimental results obtained by X-ray diffraction for the crystal structure of cellulose I beta at room and high temperatures, as well as against the temperature-dependent IR measurements describing the variation of hydrogen bonding patterns. Distinct low and high temperature structures were identified, with a phase transition temperature of 475-500 K. In the high-temperature structure, all the origin chains rotated around the helix axis by about 30A degrees and the conformation of all hydroxymethyl groups changed from tg to either gt on origin chains or gg on center chains. The hydrogen-bonding network was reorganized along with the phase transition. Compared to the previously employed GROMOS 45a4 force field, GLYCAM06 yields data in much better agreement with experimental observations, which reflects that a cautious parameterization of the nonbonded interaction terms in a force field is critical for the correct prediction of the thermal response in cellulose crystals.
Place, publisher, year, edition, pages
2011. Vol. 18, no 2, 207-221 p.
Cellulose I beta, Molecular dynamics, GLYCAM06, Thermal response
IdentifiersURN: urn:nbn:se:kth:diva-31887DOI: 10.1007/s10570-010-9491-xISI: 000288253000002ScopusID: 2-s2.0-79952533565OAI: oai:DiVA.org:kth-31887DiVA: diva2:406948
FunderSwedish e‐Science Research Center
QC 201103292011-03-292011-03-282012-05-24Bibliographically approved