Fig. 6.

FESEM images of NFC films from non-treated and enzymatically treated samples. R (initial refined pulp), C₉ (Cel9B), C_mix (cellulase mixture consisting in Fibercare and Celluclast), S (LPMO), SC_mix (LPMO and C_mix) and L_Tempo (Laccase_Tempo treatment). Enzymatic treatments with cellulases were performed at 50 °C, pH 5, for 18 h with 10 U g⁻¹ odp of enzyme. (In the case of C_mix the enzymatic dose was 20 U g⁻¹.) Enzymatic treatment with LPMO (S) was performed at 50 °C, pH 6, for 72 h with 4 mg of enzyme g⁻¹ odp in the presence of ascorbic acid and hydrogen peroxide. Enzymatic treatment with Laccase_Tempo was performed at room temperature, pH 5, for 18 h at 60 U g⁻¹ odp of laccase and 8% odp of Tempo