Thermal response in crystalline Ibeta cellulose: a molecular dynamics study

Area of Science:

• Materials Science
• Computational Chemistry
• Biophysics

Background:

• Cellulose Ibeta is a key crystalline polymorph of cellulose.
• Understanding its thermal properties is crucial for material applications.

Purpose of the Study:

• To investigate the influence of temperature on the structure and properties of cellulose Ibeta crystals.
• To elucidate the transition pathway between low- and high-temperature states.

Main Methods:

• Molecular dynamics simulations using the GROMOS 45a4 force field.
• Comparison of simulated data with experimental results at 300 K and 500 K.

Main Results:

• Simulations at 300 K showed good agreement with experimental data.
• At 500 K, density decreased, cell parameters a and b expanded, and c contracted.
• Hydrogen bonding and Young's modulus changed, with a proposed transition pathway involving chain rotation and hydroxymethyl group reorientation.

Conclusions:

• Temperature induces significant changes in cellulose Ibeta crystal structure and mechanical properties.
• A gradual transition around 450 K is suggested, involving structural rearrangements.
• Simulated data align well with experimental observations of temperature-induced changes.