烯基木质素聚集体的耗散颗粒动力学研究OA

Lignin is a natural aromatic polymer with significant potential to be used as a renewable bioresource in the functional materials field.The aggregation behavior of mixed 1,4-dioxane/water solvents was investigated by dissipative particle dynamics(DPD)simulations using mesoscopic models of alkali lignin(AL)and its alkenyl derivative(alkenyl alkali lignin,A-AL)molecules.The results show that both AL and A-AL molecules could form stable spherical aggregates.However,due to the enhanced hydrophobicity imparted by the introduced alkenyl group on the C3 side chain,A-AL molecules exhibited significantly faster aggregation kinetics than AL molecules.Furthermore,A-AL molecules could form aggregates with various morphologies,including lamellar,cylindrical,and spherical structures under different 1,4-dioxane concentrations and A-AL content conditions.It was found that both low molecular weight(～2 000 Da)and high molecular weight(more than 120 000 Da)A-AL molecules are incapable of forming uniform and stable spherical aggregates.To achieve the preparation of homogeneous and stable spherical A-AL aggregates,it is recommended to maintain a water-to-1,4-dioxane volume ratio greater than 8.0:2.0,an A-AL content of 3.0%-10.0%(volume fraction),and the use of an AL sample with a molecular weight ranging from 4,000 to 60,000 Da.The results of this paper will give a theoretical basis for lignin modification and the preparation of lignin-based functional aggregates.