Fabrication of Antibacterial and Functional Films from Starch-Polyvinylpyrrolidone Composite Using Plasma Treatment and Silver Nanoparticles.

Biopolymers and water-soluble nontoxic synthetic polymer composites using silver nanoparticles are astute approaches for antibacterial film fabrication. Moreover, surface treatment of the biopolymeric composite film by cold plasma can enhance the biocidal activity. Silver nanoparticles were synthesized by using the reduction method. Films were fabricated with different ratios of rice starch and polyvinylpyrrolidones (PVP) (1:0, 1:1, and 3:1), with and without silver (Ag) nanoparticles. A plasma jet was used to treat the film's surfaces by placing the Film 0.5 cm below the plasma discharge. Surface morphology was monitored by scanning electron microscopy (SEM), and the existence of Ag nanoparticles in the film was confirmed by X-ray diffraction (XRD). The UV-vis spectrum at 420 nm confirms Ag nanoparticles, which have an average hydrodynamic radius of 207.3 ± 21 nm, measured by a Zetasizer, and an average particle size of 69.85 ± 2.13 nm, analyzed by transmission electron microscopy (TEM). Moisture content, water absorption, swelling properties, tensile strength, contact angle, and DSC and TGA of all films were studied. It was observed that the moisture content, moisture absorption, and tensile strength increased after the addition of PVP, with few exceptions. All these properties were improved in plasma-treated films. Crystallinity, thermal stability, and glass transition temperature ( ) were also enhanced when the surface of the films was treated with cold plasma. The antibacterial activity of these films was evaluated by using the agar diffusion method, and silver nanoparticle-containing films showed good antibacterial properties, which increased significantly after plasma jet treatment of the films. The findings indicated that the plasma surface-treated silver nanoparticle-incorporated rice starch-PVP composite film has the potential to be used as an antibacterial film. These films can be used as bandages for wound healing and antibacterial packaging.