Supporting Information Robust Bioinspired Graphene Film via π-π Cross-linking Hong Ni, a Feiyu Xu, a Antoni P. Tomsia, a,b Eduardo Saiz, c Lei Jiang, a and Qunfeng Cheng* a a Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, 100191, P. R. China b Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA c Department of Materials, Centre for Advanced Structural Ceramics, Imperial College London, London SW7 2AZ, UK. * Correspondence should be addressed to Qunfeng Cheng, E-mail: cheng@buaa.edu.cn S-1
Figure S1. AFM image of GO nanosheet with thickness of ~ 0.75 nm. S-2
Figure S2. TGA curves of GO, rgo, rgo-ap-dss-i, rgo-ap-dss-ii, rgo-ap-dss-iii and rgo-ap-dss-iv samples. The corresponding AP-DSS contents in different samples are shown on the right side of the graph. All the samples were tested in an argon atmosphere at a heating rate of 15 C min -1. Figure S3. XRD patterns of rgo, rgo-ap-dss-i, rgo-ap-dss-ii, rgo-ap-dss-iii and rgo-ap-dss-iv samples. The corresponding d-spacing is 3.53 Å, 3.63 Å, 3.64 Å, 3.72 Å and 3.72 Å, respectively. The increase of the d-spacing is due to the intercalation of AP-DSS molecules into the interspace of graphene layers. S-3
Figure S4. The tensile strength and toughness of rgo-ap-dss nanocomposites with different contents of AP-DSS molecules. Figure S5. Dynamic stress-strain curves of (a) rgo film, (b) rgo-ap-dss-iii nanocomposite. S-4
Table S1. Mechanical properties of GO, rgo, rgo-ap-dss-i, rgo-ap-dss-ii, rgo-ap- DSS-III, and rgo-ap-dss-iv samples. Sample Stress (MPa) Strain (%) Toughness (MJ m -3 ) GO 118.9 ± 12.1 2.3 ± 0.2 1.4 ± 0.3 rgo 131.1 ± 5.8 4.3 ± 0.4 2.5 ± 0.2 rgo-ap-dss-i 310.2 ± 29.6 5.1 ± 0.1 4.7 ± 0.3 rgo-ap-dss-ii 458.2 ± 45.3 5.4 ± 0.1 9.8 ± 1.0 rgo-ap-dss-iii 538.8 ± 31.6 6.6 ± 0.8 16.1 ± 3.0 rgo-ap-dss-iv 480.5 ± 14.7 5.6 ± 0.2 12.5 ± 0.3 S-5
Table S2. Electrical conductivities of rgo, rgo-ap-dss-i, rgo-ap-dss-ii, rgo-ap-dss- III and rgo-ap-dss-iv samples. Sample Electrical conductivity (S cm -1 ) rgo 243.9 ± 9.6 rgo-ap-dss-i 357.9 ± 6.3 rgo-ap-dss-ii 430.0 ± 8.6 rgo-ap-dss-iii 321.9 ± 11.8 rgo-ap-dss-iv 234.0 ± 10.1 S-6
Table S3. Comparison of tensile strength, toughness, and conductivity of rgo-ap-dss film with other GO/rGO-based composite films cross-linked through non-covalent bonding. Sample Electrical conductivity (S. cm -1 ) Toughness (MJ. m -3 ) Tensile strength (MPa) Reference rgo-pb 2 0.01 8.4 [1] rgo-fpeg 0.034-45 [2] GO-PVA - 0.1 80.2 [3] rgo-pva 52.65 2.52 188.9 [4] GO-PMMA - 2.35 148.3 [3] rgo-papb 337 7.5 382 [5] GO-CNC - 4 490 [6] rgo-cnc 50 3.9 655 [6] GO-Zn 2+ - 0.32 142.2 [7] GO-Ca 2+ - 0.31 125.8 [8] GO-Mg 2+ - 0.13 80.6 [8] GO-Al 3+ - 0.23 100.5 [9] GO-SL - 2.2 300 [10] rgo-sl 13.5 2.8 300 [10] rgo-ap-dss-ii 430.0 9.8 458.2 This work REFERENCE (1) Xu, Y.; Bai, H.; Lu, G.; Li, C.; Shi, G., Flexible graphene films via the filtration of watersoluble noncovalent functionalized graphene sheets. J. Am. Chem. Soc. 2008, 130, 5856-5857. (2) Georgakilas, V.; Tiwari, J. N.; Kemp, K. C.; Perman, J. A.; Bourlinos, A. B.; Kim, K. S.; Zboril, R., Noncovalent Functionalization of Graphene and Graphene Oxide for Energy S-7
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