Shifting to Transparent/Hazy Properties: The Case of Alginate/Network Cellulose All-Polysaccharide Composite Films

Light-management films made entirely from natural polymers with tunable haze properties are developed via a facile approach. A novel green method based simply on the blending of network cellulose (NC)/water suspension with alginate (CaAlg) aqueous solution is proposed. The unique NC suspension created by a controlled hydrolysis of microcrystalline cellulose acts as the scatterer media while alginate serves as the transparent host matrix. NC features isotropic intertwined network of nanofibers that contributes to light scattering and produces optical haze. The opaque but hazy NC is dispersed purposefully in the alginate film, where its original properties are preserved owing to its poor solubility in water. Additionally, the dispersion notably increases the roughness of the composite film surface and acts as a light scatterer. Eventually, composite CaAlg/NC film with high transparency (>94%) and customized haze (15-73%) at 550 cm^-1 wavelength is fabricated. Herein, the transparent alginate is successfully combined with the hazy cellulose of uniformly distributed nanofibers by blending to fabricate transparent/hazy all-natural films. The fabricated films exhibit high transparency with tailored transmission haze. The film is highly fitting for large-scale production and adequate to meet different haze requirements to accommodate different applications such as privacy protection films and antiglare/antireflection coatings.