Simultaneous reduction and functionalization of graphene oxide sheets with tannic acid for a strong composite material with multi-modally interactive interfaces

• Published in: Diamond and related materials 2021-11, Vol.119, p.108565, Article 108565
• Main Authors: Kwon, Yoo-Bin, Go, Su-Hyeon, Choi, Changsoon, Seo, Tae Hoon, Yang, Beomjoo, Lee, Min Wook, Kim, Young-Kwan
• Format: Article
• Language: English
• Subjects: Artificial nacre; Bonding strength; Chemical reactions; Composite materials; Coordination; Covalent bonds; Crosslinking; Eco-friendly; Graphene; Graphene oxide; Hydrogen bonding; Lamellar structure; Nacre; Polyethyleneimine; Reduction; Sheets; Surface modification; Tannic acid; Tensile strength
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2021.108565

A multi-modally interactive interface is investigated to develop a strong structural material based on hybridization of graphene oxide (GO) and tannic acid (TA) through cross-linking with coordination and covalent bonds. GO is reduced and functionalized with TA by a simple wet-chemical reaction. The resulting TA-reduced and functionalized GO (TA-RGO) sheets are macroscopically assembled into lamellar structured paper like artificial nacre by vacuum-assisted filtration. The assembled TA-RGO paper is sequentially cross-linked by Fe3+ ion and polyethyleneimine (PEI) to form a strong interface through multimodal interactions such as hydrogen bonding, covalent bonding, coordination and π-π interactions. The suspended, assembled and cross-linked TA-RGO sheets are systematically characterized by various analytical tools. By forming the multimodal interactions, the tensile strength, modulus and toughness of GO paper were enhanced from 59.5 ± 4.1 MPa, 7.8 ± 1.4 GPa, and 765 ± 112 kJ/m3 to 167.7 ± 15.4 MPa, 17.6 ± 0.4 GPa, and 1484 ± 192 kJ/m3, respectively. Based on the results, we clearly demonstrated TA can be harnessed as a multifunctional agent for reducing, functionalizing and cross-linking RGO sheets to construct a strong structural material by forming multi-modally interactive interfaces. [Display omitted] •Tannic acid (TA) is used to reduce, modify, and cross-link graphene oxide (GO).•TA-reduced GO paper is sequentially cross-linked with Fe3+ and polyethyleneimine.•The cross-linking reinforces their mechanical property with multiple interactions.