Figure 11.

Examples of techniques used to investigate the effect of wet-strength agents on paper’s physico-chemical properties. (a,b) SEM micrographs of paper fibers (a) and paper fiber reinforcement by CMC-aGO (b) (red circles represent interfibrillar voids) (reproduced from [81]); (c) tensile strength–strain behavior of cellulose acetate butyrate (CAB)/acetone-treated cellulose nanofibers (A-CNF) with different amounts of the bio-derived crosslinker polyisocyanurate D376N. (A) A-CNF; (B) CAB500-5; (C) CAB/D376N (0 wt%); (D) A-CNF/D376N (3.9 wt%); (E) CAB/A-CNF/D376N (7.7 wt%); (F) CAB/A-CNF/D376N (14.3 wt%); (G) CAB/A-CNF/D376N (24.5 wt%). (Reproduced from [82]); (d) FTIR spectra of cottonseed protein (CSP) isolate and paper samples treated with CSP or CSF and nanocellulose (CNC), expansion of the cellulosic region of the amide bonds (1750 cm⁻¹ to 1400 cm⁻¹) (reproduced from [83]).