Fig. 5.

Barrier properties to air (Bekk permeability) and water (water drop test) of NFC films. R (initial refined pulp), C_k (cellulase control treatment), C₉ (Cel9B), C₅₀ (Sertec20 cellulase), C_F (Fibercare cellulase), C_ll (Celluclast cellulase), C_mix (cellulase mixture consisting in Fibercare and Celluclast), S_k (LPMO control treatment), S (LPMO), SC_mix (LPMO and C_mix), L_Tempo (Laccase_Tempo treatment) and Com (commercial NFC). 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