Self-assembly of Alkali Lignin in Tetrahydrofuran

Alkali lignin (AL) was used as a polyanion to form layer-by-layer self-assembled film with PDAC as a polycation. The effects of temperature and concentration on the adsorption characteristics of AL were investigated. Iodine was added into AL solutions to study the role of pi-pi interaction in self-assembly of AL and PDAC. Results show that the self-assembly of AL/PDAC is mainly driven by pi-pi interaction and electrostatic interaction. A higher temperature or a larger concentration can enhance the aggregation of lignin. I-2 can form lignin iodine charge transfer complexes with AL to reduce the degree of aggregation of AL, so the adsorbed amount of AL decreases significantly with increasing iodine contents.