The effect of solvents on crystal morphology of sucralose: Experiments and molecular dynamics simulation studies

Abstract

• The crystal morphology of sucralose was precisely simulated via the MAE model. • Roughness and solvent-crystal contacting angle are vital for solvent adsorption. • The solvent-crystal interactions are dominated by strong hydrogen bonds. • Different inhibitory degree of solvents on two faces arouses varied aspect ratios. The effect of solvents on sucralose crystal morphology was studied both experimentally and theoretically in water, methanol and ethanol. Hirshfeld surfaces and 2-D fingerprint plots were used to investigate the solute-solute interactions which were involved in the calculation of crystal morphology in vacuum. Moreover, solvent-crystal interactions were considered by using the modified attachment energy model and molecular dynamics simulation, leading to a precise simulation of sucralose crystal morphology in all the three solvents. In order to have a better understanding of the solvent effect, surface structure as well as the strength and the type of the solvent-crystal interactions on the morphologically important faces including the (0 1 1) and (1 0 1) faces were discussed. Both surface roughness and solvent-crystal contacting angle were found to be important to the effective solvent adsorption. Based on the diffusion coefficient of solvent molecules on the crystal faces, the crystal morphology of sucralose was also affected by the solvent diffusion. Radial distribution function analysis showed strong hydrogen bonds between the hydrogen atoms in the solutes and the oxygen atoms in the solvents on the (0 1 1) and (1 0 1) faces. Furthermore, different inhibitory degrees of the solvents on the two faces can cause varied aspect ratios of crystals in the tested three solvents.