Studying the effect of zinc oxide nanoparticles and cellulose nanofiber on the morphological, structural, thermal, mechanical and barrier properties of nanocomposite film based on Barhang (Plantago major L) mucilage

The aim of this research was to prepare a nanocomposite film based on Barhang (Plantago major L) seed gum. Zinc oxide (ZnO) and cellulose nanofiber (CNF) nanoparticles at the concentrations of 4 and 8% w/w were incorporated for improving the morphological, structural, thermal, water vapor permeability and mechanical properties of films. The FT-IR results confirmed the occurring of new interactions between nanoparticles and mucilage polysaccharides. XRD results indicated that the effect of ZnO on semi-crystalline structure of Barhang film is higher than the effect of CNF. The neat film has a smoth surface, but the roughness increased by addition of nanoparticles. According to TGA results, the thermal stability of films was affected by incorporation of nanoparticles, but the effect of CNF on improving the thermal stability of film was more than ZnO. The addition of nanoparticles at the concentration of 4% had no effect on the thickness of films but by increasing to 8%, the thickness increased. Moisture content and moisture absorption of films was also decreased significantly by incorporation of nanoparticles. The water vapor permeability of films was dependent on the concentration of nanoparticles and at 4%, it decreased significantly but at 8% concentration, the permeability increased again due to the aggregation of nanoparticles and their hydrophilic nature. The water contact angle of films’ surface increased by addition of ZnO but the CNF caused to decrease this value due to its hydrophilicity. The effect of CNF on improving the mechanical properties of films was better than ZnO. The CNF had the most effect on increasing tensile strength, elastic modulus and elongation to break. In general, this research indicated that by using organic and inorganic nanoreinforcements, the improving of the properties of Barhang seed gum based films is possible and the effect of CNF is more than ZnO.