Green seaweed (Ulva ohnoi) as a new eco-friendly source for preparing transparent and functional regenerated cellulose composite films

In recent years, algae blooms have caused severe problems, such as environmental pollution, the disruption of tourism, and shore-based activities, in many coastal areas worldwide. To reduce these problems, algae biomass (Ulva ohnoi) was used to develop a fully transparent regenerated cellulose-based composite film for food packaging. Cellulose was extracted from U. ohnoi using chemical treatments and characterized using scanning electron microscopy, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The extracted cellulose was activated, dissolved in dimethylacetamide/lithium chloride, and regenerated in ethanol to prepare a flexible transparent cellulose film. The mechanical strength, UV-visible light transmittance, and oxygen barrier properties of the regenerated cellulose film were characterized. The tensile strength, elongation at break, Young modulus, T-660, and oxygen permeability at 50% relative humidity of the regenerated cellulose film were 69.21 +/- 9.20 MPa, 13.43 +/- 2.43%, 4016.2 +/- 623.4 MPa, 90.71%, and 1898.4 +/- 195.2 cc center dot mu m/(m(2)center dot day center dot atm), respectively. The regenerated cellulose was mixed with zinc oxide nanoparticles and curcumin to prepare antibacterial and antioxidant functional composite films. These functional composite films displayed strong antibacterial activities against various Gram-negative and Gram-positive bacteria.