Bacterial cellulose nanofibers layer with water-floating, photothermal, bio- and electro-active features

Chemical modification of bacterial cellulose (BC) nanofibers layer with high purity, crystallinity, and water-holding capacity with good mechanical properties helps with its application in various fields. Here, BC was modified with copper acetate (CA) and dopamine hydrochloride (DA) to synthesize copper-based nanoparticles and polydopamine on the BC to produce novel properties. The optimum sample was the one treated with (10 w/w%) copper acetate and (0.5 g/l) dopamine among copper acetate (1–10 w/w%) and dopamine (0.5–2.0 g/l) based on the antibacterial properties. FTIR-ATR spectra and FESEM images indicated well-deposited copper-based nanoparticles and DA on the surface of BC. The water contact angle increased from 18º on the raw BC to 89° on the modified BC. The BC color altered from cream to dark brown and the tensile strength increased by 206 %. The modified BC exhibited 99.8 and 99.9 % bacterial reduction against Escherichia coli and Staphylococcus aureus alongside 76.8 % cell viability. Further, DA-treated BC caused an increase in the temperature to 40 °C under IR light after 10 min as an indication of photothermal properties. Ultimately, the treated BC with CA and DA indicated anti-bacterial, photothermal, and water-floating properties with enhanced tensile strength.