Computer simulations of modified cellulose nanofibrils

The purpose of this study is to observe what modifying the surface of cellulose nanofibrils may imply for their interactions with a surrounding saline aqueous solution. This will be studied by using GROMACS, a molecular dynamic simulation software. In particular, we will analyse the modified surfaces hydrophilicity compared to native nanocellulose. This will subsequently have an impact on the nanofibrils readiness to aggregate to one another and disperse in the solution. Specifically two types of surface modifications will be studied, sulfonation and carboxy- lation. The hydrophilicity of the surfaces will be determined by analysing the density profiles of the systems wherein the modified surfaces interacts with the aqueous solutions. Also, the energies from the interactions of the simulated systems will be studied. We concluded that both modifications increases the surfaces interactions with the sur- rounding solution. Modifying the surface of the cellulose nanofibril with sulfonate will increase the surfaces attraction towards water and may provide the best rate of dispersion in aqueous solutions and best prohibit aggregation. Carboxylation of the surface provides similar hydrophilic results as the sulfonation but not as prevalent