Cellulose Extraction From Green Algae, Ulva Ohnoi, and Its Application to PVA‐Based Antibacterial Composite Films Incorporated With Zinc Oxide Nanoparticles.

Cellulose was successfully extracted from green algae (Ulva ohnoi) by chemical treatments. The contents of holocellulose and α‐cellulose significantly increased from 37.6% and 3.3% to 82.5% and 63.3%, respectively, after whole extraction treatments. The extracted cellulose (EC) was mixed to polyvinyl alcohol (PVA) to prepare EC/PVA composite films with polyethylene glycol (PEG) or glycerol (GLY) as a plasticizer. The EC/3%PVA composite film showed the highest tensile strength of 54.42 MPa because of the high PVA content. Adding GLY steeply increased the elongation of the EC/3%PVA film from 3.12% to 126.76%, but adding PEG slightly decreased to 2.63%. The EC/1%PVA/PEG composite film showed the highest visible light transmittance of 84.47%, while the addition of zinc oxide nanoparticles (ZnO‐NPs) significantly improved UV‐blocking properties. In addition, the incorporation of ZnO‐NPs on the EC/PVA‐based composite films showed excellent antibacterial activity against six Gram‐positive and Gram‐negative bacteria. [ABSTRACT FROM AUTHOR]