Lignin-Based Multilamellar Aggregates for Removing Ofloxacin Antibiotic: A Dissipative Particle Dynamics Simulation Study

Lignin, a renewable aromatic polymer, has great potential as a synthetic building block for functional materials. The effects of quaternary ammonic methylation of alkali lignin (AL) on the morphologies and ofloxacin antibiotic (OA) removal application from water are investigated by using the dissipative particle dynamics (DPD) simulation method. Untreated AL can form spherical aggregates, but the phenylpropane units of untreated AL and loaded broad-spectrum OA molecules are randomly distributed in aggregates. However, if quaternary ammonic groups are grafted onto all orthopositions of the phenolic hydroxyl groups (100-QAMAL), then multilamellar spherical aggregates are obtained and OA molecules are entrapped in the aggregates. To prepare multilamellar spherical aggregates with an ordered and regular layered structure, <15 v% of 100-QAMAL and low molecular weights of AL (≈4700–9400 Da) are suggested to be used. Lignin-based multilamellar spherical aggregates can be adopted as potential functional carriers for removing pollutant OA from water.