Ternary Synergistic Strengthening and Toughening of Bio-Inspired TEMPO-Oxidized Cellulose Nanofibers/Borax/Polyvinyl Alcohol Composite Film with High Transparency

Abstract

Utilizing and exploring degradable and renewable resources are of importance for environmental protection, and one efficient strategy is to use green cellulose-based materials as alternatives of eco-unfriendly polymers. However, compared to other polymeric and inorganic fibers, the cellulose-based materials show weak mechanical strength, which limits their applications in some extreme conditions. To obtain TEMPO-oxidized cellulose nanofiber (TOCN) films with high strength and toughness simultaneously, we prepared the ternary TOCN/borax/polyvinyl alcohol (PVA) composite films through a vacuum-assisted filtration method in this work. By controlling the additional contents of borax and PVA in the composites, the stress, elongation, and toughness of the TOCN/borax/PVA composites can be up to 226.53 MPa, 5.98%, and 9.84 MJ•m −3 , which are 1.89, 2.51, and 6.39 times of a pure TOCN film, respectively. The outstanding mechanical behaviors of the TOCN/borax/PVA composites are attributed to the synergic strengthening effect of hydrogen and covalent bonding as well as the intrinsic and extrinsic toughening mechanisms. In addition, the TOCN/borax/PVA composites also maintain a high visible-light transparency of 83.36% at 800 nm, which has potential applications in solar cells, transparency electrodes, and flexible electric devices as substrates.

Triple-Responsive, Multimodal, Visual Electronic Skin toward All-in-One Health Management for Gestational Diabetes Mellitus

“…The binding energies of C 1s are 283.9, 285.2, and 287 eV, respectively, which are attributed to C–C/C–H, C–O, and C–O–B in the PVA-B hydrogel . The C–O binding energy of the PB-MC hydrogel was enhanced and shifted to 285.4 eV, indicating that a strong hydrogen bond was formed between PVA and MC, which was consistent with the conclusion of FTIR. Two distinguishable peaks, B–O–C (191.2 eV) and B–O–B (190.4 eV), were generated by splitting the B 1s spectrum.…”

“…As shown in Figure a, TCPs@PB-MC, TCPs@PB-HPC, and TCPs@PB-HPMC hydrogels were synthesized by using a simple and efficient method. PVA is selected for its excellent biocompatibility, flexibility, and abundant functional groups of hydroxy . Borax is a kind of compound with nontoxicity, inexpensiveness, easy storage, and availability .…”

Construction methods and biomedical applications of PVA-based hydrogels

“…The second common cross-linking agent is borates, which polymerize PVA chains through borate ester bonds (Songfeng et al, 2020;Hamd-Ghadareh et al, 2022) (Figure 2B). Borax hydrolysis yields B(OH) 4 -, which forms diol-borate bonds with the widely present intermolecular hydroxyl groups of PVA.…”

Comparative study on proton conductivity of a polypyridinyl multicarboxylate-based hydrogen-bonded organic framework and related chitosan composite membrane

“…However, their use in the research field of proton conduction remains underexplored. 26–29 Considering that the H-bonding interactions among HOFs and CS can enhance the mechanical properties of composite membranes and form continuous proton transport channels, 30–32 we hope to prepare a highly stable HOF and introduce it into the CS film, and then compare their σ values and conduction mechanisms to provide useful inspiration for the preparation of composite films with high proton conductivity.…”