Hygroscopic properties of natural oligosaccharides; model development and validation for interactions with water

• Applicant: Dr. Andrea Grafmüller
• Subject Area: Theoretical Chemistry: Electronic Structure, Dynamics, Simulation
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 220972260

The objective of the project is to determine the water swelling properties of hemicellulose polysaccharides by computer simulations. The high degree of swelling of these molecules enables the generation of reliable actuated movement in plant tissues without requiring cellular activity. Therefore such systems serve as inspiration for the design of adaptive materials and actuators with a wide range of potential applications. To use these properties to full advantage, their molecular origin and structure-function relations ought to be understood. Here we propose to build and validate a computational model for hemicellulose backbone molecules in direct comparison with experiments. Atomistic simulations of small polysaccharides will be employed to gain a concise understanding of local interactions of small polysaccharides with water, its influence on their conformational freedom and the swelling properties. Based on these simulations, a coarse grained (CG) model is to be developed to study swelling properties on larger length and time scales inaccessible to atomistic simulations. The effective model will be created in two stages; (i) conformational properties will be captured by recording potentials of mean force (PMF) for glycosidic linkages, and (ii) to model saccharide-water interactions as accurately as possible in CG resolution, we will employ the force matching procedure that infers optimal CG interactions directly from the atomistic simulations. We propose to combine this with the PMF charts for bonded interactions.

• DFG Programme: Research Grants