• Polymer Coating

The HCl-protonated m-phenylenediamine was mixed with glutaraldehyde, which formed the oligomer solution due to protonation. The pretreated bacteria cellulose (pBC) was immersed in precursor mixture to absorb the oligomers into matrix of pBC. The poly Schiff base was deposited on cellulose nanofibers by tuning the pH to base. The detail of procedure was given in Supplementary Sections S1.1 and S1.2.

The relative content of poly Schiff base in pBC was estimated according to the following equation:

$$D\% = \frac{W\_{\text{product}} - W\_{\text{BC}}}{W\_{\text{product}}} \times 100\% \tag{1}$$

where the D% is the content percentage of poly Schiff base in the composites, *W*product is the total mass of composites, WBC is the mass of bacteria cellulose or porous bacteria cellulose.
