Residual Lignin and Zwitterionic Polymer Grafts on Cellulose Nanocrystals for Antifouling and Antibacterial Applications

Hybrid materials from nanocellulose, lignin, and surface- grafted zwitterionic poly(sulfobetaine methacrylate) (PSBMA) chains are prepared to attain antifouling bio-based nanomaterials with enhanced antibacterial performance. The grafting of PSBMA from both cellulose and lignocellulose nanocrystals (CNC and LCNC, respectively) is attempted; however, the materials' analysis with FTIR, XPS, and solid-state C-13 NMR reveals that the grafting on LCNC is negligible. Antifouling and antibacterial performances of CNC and LCNC, as well as PSBMA-grafted CNC, are evaluated by using quartz crystal microbalance with dissipation monitoring, confocal microscopy, and the agar diffusion method using bovine serum albumin and E. coli ACTT 8937 as protein model and bacterial model, respectively. The results demonstrate that the grafting of CNC with PSBMA improves the antifouling and antibacterial activity of the material compared to pristine CNC and LCNC.