Fig. 4.

MD simulations of lignin in different solvents. (A) Representative structures from MD simulations of single lignin molecules in three solvents at 25 °C; carbon atoms shown in cyan and oxygen in red. (B) Radial distribution function (RDF), a measure of the local density of a solvent at a distance r from the lignin, between lignin and THF (orange) or water (blue) in either the cosolvent (solid lines) or the pure solvent (dashed lines). (C) RDF in the cosolvent environment between THF atoms and polar lignin atoms, defined here as having a partial charge |q| > 0.3 (red) or nonpolar, with |q| < 0.3, (red) atoms. Data are normalized to 1 at large distances. All RDFs are calculated with respect to nonhydrogen atoms of both lignin and the solvents.