Speaker
Description
Neutron scattering experiments provide valuable insights into the nanoscopic properties of matter. In this contribution we study water absorbed to cellulose leading to the conclusion that water absorbed to cellulse is adherend with its hydrogen bonds fixed to the cellulose, indicating that steric effects play only a minor role.
The time- and lenghtscales probed by neutron scattering experiments are also accessible through molecular dynamics (MD) simulations. If the simulations reproduce the experiments, they can give further insight into the material properties on the nanoscopic scale.
MD simulations were created for water with partially fixed water molecules at different temperatues to compare it to experiemental data of water absorbed to cellulose. The fixed water molecules served as minimalistic hydrogen bond donors and acceptors such as the OH groups on cellulose.
The simulations were first evaluated for their soundness followed by a comparison to the experimental data.
We observe a decline of the diffusion coefficient the more water molecules are fixed and the colder the simulated water is.
The comparison of simulation and experimental data shows a generell agreement of the data regarding the structure. While the agreement of simulation and experiment concering the dynamics is good, differences become apperent at smaller Q-values, i.e. longer real space distances.
