Impact of nano-sized cerium oxide on physico-mechanical characteristics and thermal properties of the bacterial cellulose films

Abstract

A set of nanocomposite film materials based on bacterial cellulose containing nanoparticles of cerium dioxide was prepared. An investigation into the structural and morphological characteristics of the films has been performed, their thermal, mechanical and tribological properties were determined. A protocol of the nanocomposite materials formation used in the work was shown to provide a homogeneous distribution of ceria nanoparticles in the matrix polymer volume in addition to the presence of certain amount of broadly size-dispersed cerium oxide aggregates in the bulk film. The increase of nanoparticles concentration in the composite provokes a progressive growth of the Young's modulus and strength of the film material. Introduction of nanoparticles into the polymer causes the stabilization of sliding friction processes in the tribocontact with steel as well as the decrease of intensity in the wear rate of the film. An increase of the nanoparticles concentration results in a decrease of the material thermal stability.

Strengthening Cellulose Nanopaper via Deep Eutectic Solvent and Ultrasound-Induced Surface Disordering of Nanofibers

“…The maximal effect of the combination of ultrasound and DES treatment observed for the E+ sample can be attributed to the following: due to the smaller size of the ethylene glycol molecule, it penetrates faster inside the cellulose and better facilitates the destruction of amorphous parts compared to glycerol; in the case of the paper obtained using ethylene glycol and ultrasound, the maximum Young’s modulus of 9.2 GPa was observed, whereas for glycerol it was 7.4 GPa. Finally, the elastic modulus for all films prepared using DES treatment in this work was higher than the value of 6.41 GPa that has been reported for pure BC [ 85 ].…”

“…Strength increases from 78 up to 121 MPa and from 81 up to 134 MPa for the BC-NFs prepared with EG and Gly-based DES, respectively. Moreover, the strength of the ultrasound-treated samples in the presence of DES is higher than the 96 MPa that was reported earlier for the initial BC [ 85 ]. The elongation at break for the samples prepared with ultrasound is also higher.…”

“…To conclude, the mechanical characteristics, such as Young’s modulus and tensile strength, of the BC-NFs prepared via treatment with DES combined with ultrasound were higher than the characteristics reported for pure BC [ 85 ]. It was higher than the 2.7 GPa and 98 MPa reported for the acidic DES-pretreated ramie nanofibers [ 62 ] and comparable with 12.2 GPa and 134 MPa reported for the BC nanopaper prepared using high compaction force (1 t) at 120 °C [ 88 ].…”

Synthesis of Cerium Oxide Nanoparticles in a Bacterial Nanocellulose Matrix and the Study of Their Oxidizing and Reducing Properties

“…Despite the fact that many works have been devoted to the preparation of nanocomposite materials based on BC and metal oxide nanoparticles [ 12 , 18 , 23 ], the synthesis of BC–CeO 2 NPs nanocomposites has not been widely considered. Nanocomposites are usually prepared by mixing dispersions of cellulose and other polysaccharides with stabilized CeO 2 NPs and then forming the material [ 15 , 16 , 17 ]. This is primarily due to the method of obtaining cerium oxide nanoparticles by their precipitation from solutions of cerium (III) salts with ammonium hydroxide in a non-aqueous medium at a temperature of 40–60 °C.…”

“…Recently, the inclusion of cerium oxide nanoparticles (CeO 2 NPs) in nanocomposite materials based on BC or its composites with polysaccharides for medical use has been discussed in the literature [ 15 , 16 , 17 , 18 , 19 , 20 ]. In these works, special attention was paid to the aspects of tissue engineering, e.g., BC-based stem cell proliferation scaffolds, as well as antioxidant and enzymatic mimetic activities of CeO 2 NPs in composites.…”