One of the most important factors governing the properties of composite materials is the interface between the filler and the polymer matrix. The interfacial properties in nanostructured composites are, due to the small length scales involved, highly dependent on molecular-scale interactions. These interactions may be fine-tuned to obtain some desired property, by carfully chosing the right combination of filler (nanoparticle) and polymer matrix, and by chemical modifications of those. From a materials design perspective, it would be useful to be able to assess material properties based on the compopsition of the interface, without need for actual synthesisation and production.
In this project we aim to use MD simulations of two different classes of nanoparticle interfaces (cellulose nanofibers and nano clays) and their interactions with different polymers (cellulose derivatives, hemicelluloses, and organic polymers like poly-(vinyl alcohol)). Two different approaches will be used.
1) Potential of Mean Force calculations for the adsorption of polymers to nanoparticles (see refs 1-3).
2) Effect of chemical surface modification in terms of change in surface free energy from "computational alchemy" calculations in which OH-groups are substituted to other functional groups.
The aim is to create a framework for relatively high throughput, for efficient screening of different material combinations. Results from the calculations will be compared with real composite materials which can be produced in our lab.
 Wang et al., J. Mater. Chem. A, 2014, 2, 9541
 Wang et al., Biomacromolecules 2015, 16, 257−265
 Wang et al., RSC Adv., 2015, 5, 54580
 Wang et al., Comput. Mater. Sci., 2017, 128, 191-197