Preparation and characterization of nano‐SiO₂ reinforced alginate‐based nanocomposite films (II)

Abstract

Crosslinked alginate-based nanocomposites at different SiO 2 contents were prepared successfully by blending the nano-SiO 2 solution into low concentration alginate solution (0.5 wt %), with the alginate concentration increased step by step to the resulted concentration, in this course glycerol was used as plasticizer and 5 wt % CaCl 2 as crosslinker. The combined effect of SiO 2 content (1.5-8 wt %) on the microstructural, physical, mechanical, and optical properties of the nanocomposite films were investigated. The results showed that tensile strength and elongation was improved by about 40.33% and 89%, respectively, upon increasing the SiO 2 content to 4.5 wt %. In addition, water vapor permeability and swelling degree decreased by 19% and 16% with increasing SiO 2 content up to 8 and 4.5 wt %, respectively with respect to pure crosslinked alginate film. Thermogravimetric analysis also revealed that nano-SiO 2 can improve the thermal stability of sodium alginate films produced by this method.

Biopolymer-Based Films from Sodium Alginate and Citrus Pectin Reinforced with SiO2

“…As the SiO 2 concentration increased, it could be seen that the broad peak at 2θ ≈ 13° reduced in intensity, indicating a slight reduction in the crystallinity of the blend film. Similar behavior was observed in the case of incorporating SiO 2 in SA films [ 23 ] and adding montmorillonite clay to these films [ 35 ]. It is noteworthy that, even with the increase in SiO 2 concentration, the typical broad and strong diffraction peak at 2θ ≈ 23° of its amorphous structure was not observed in any of the samples, confirming that there was good filler dispersion along the biopolymer matrix.…”

“…The incorporation of different SiO 2 concentrations in sodium alginate or pectin films was investigated by evaluating the physical, chemical, and optical properties of the films [ 23 , 24 , 25 ]. Pectin films with SiO 2 showed that nanoparticles can reduce water-vapor permeability by 30–60%, compared to films without nanoparticles [ 25 ].…”

“…Pectin films with SiO 2 showed that nanoparticles can reduce water-vapor permeability by 30–60%, compared to films without nanoparticles [ 25 ]. Films with SiO 2 concentrations between 0 and 8% were produced, the tensile strength and elongation at break being higher for the composition of 4.5% SiO 2, and the water-vapor barrier of the films reduced with increasing concentrations of SiO 2 [ 23 ]. The application of low SiO 2 concentrations (0 to 1.5%) in sodium alginate films resulted in better thermal stability of the films; nevertheless, this did not affect the morphological or barrier-related properties [ 24 ].…”

“…The application of low SiO 2 concentrations (0 to 1.5%) in sodium alginate films resulted in better thermal stability of the films; nevertheless, this did not affect the morphological or barrier-related properties [ 24 ]. The mechanical and barrier properties of SiO 2 embedded films depend on the concentration and dispersion of the reinforcing agents in the biopolymer matrix [ 23 ]. Thus, it is important to investigate which SiO 2 concentration can improve the performance properties of each biopolymer matrix.…”

Polysaccharide-Based Packaging Functionalized with Inorganic Nanoparticles for Food Preservation

“…Furthermore, it is cheap and commercially available [82]. Functionalization of polysaccharide using silicon dioxide nanoparticles have received attention due to their high number of silanol groups, and to the ability to form hydrogen bonds with the biopolymer enhancing their technological and functional properties, suitable for food preservation [83][84][85]. Table 5 summarizes the application of polysaccharide-silicon dioxide packaging and their effects on quality parameters of some food products.…”