Martini 3 model of surface modified cellulose nanocrystals: investigation of aqueous colloidal stability

The Martini coarse-grained force field is one of the most popular coarse-grained models for molecular dynamics (MD) modelling in biology, chemistry, and material science. Recently, a new force field version, Martini 3, had been reported with improved interaction balance and many new bead types. Here, we present a new cellulose nanocrystal (CNC) model based on Martini 3. The calculated CNC structures, lattice parameters, and mechanical properties reproduce experimental measurements well and provide an improvement over previous CNC models. Then, surface modifications with COO- groups and interactions with Na+ ions were fitted based on the atomistic MD results to reproduce the interactions between surface-modified CNCs. Finally, the colloidal stability and dispersion properties were studied with varied NaCl concentrations and a good agreement with experimental results was found. Our work brings new progress toward CNC modelling to describe different surface modifications and colloidal solutions that were not available in previous coarse-grained models. [GRAPHICS] .

Automated summary

The study presents a new cellulose nanocrystal (CNC) model based on Martini 3, reproducing experimental measurements and improving upon previous CNC models. Surface modifications and interactions with Na+ ions were investigated, along with the study of colloidal stability with varied NaCl concentrations, showing good agreement with experimental results. This work brings new progress towards CNC modelling for describing different surface modifications and colloidal solutions.