Volume 1, Issue 5, Pages 766-775 (November 2016) Self-Healing Materials Formed by Cross-Linked Polyrotaxanes with Reversible Bonds  Masaki Nakahata, Shoko Mori, Yoshinori Takashima, Hiroyasu Yamaguchi, Akira Harada  Chem  Volume 1, Issue 5, Pages 766-775 (November 2016) DOI: 10.1016/j.chempr.2016.09.013 Copyright © 2016 Elsevier Inc. Terms and Conditions

Chem 2016 1, 766-775DOI: (10.1016/j.chempr.2016.09.013) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 1 Viscoelastic Measurements (A) Photographs of the PRx-PB (20) gel, PRx-PB (20) gel with CAT, and PRx-PB (0) gel after polymerization. (B) Dependence of storage elastic moduli (G′) and loss elastic moduli (G″) on angular frequency (ω) obtained from dynamic viscoelastic measurements of the PRx-PB (20) gel (black square), PRx-PB (20) gel with CAT (red circle), and PRx-PB (0) gel (blue triangle). (C) Dependence of tan δ (= G″/G′) on angular frequency (ω) obtained from dynamic viscoelastic measurements of the PRx-PB (20) gel (black square), PRx-PB (20) gel with CAT (red circle), and PRx-PB (0) gel (blue triangle). Chem 2016 1, 766-775DOI: (10.1016/j.chempr.2016.09.013) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 2 Self-Healing of Hydrogel (A) Photographs of self-healing experiments. A cuboid (size 10 × 5 × 5 mm3)-shaped PRx-PB (20) gel was cut in half, and then two cut pieces were reattached. Several seconds after the reattachment, the two pieces were sufficiently adhered to each other to be lifted up against their own weight. (B) Stress-strain curves of the PRx-PB (20) gel (black) and the PRx-PB (20) gel after self-healing for 5 min (red). (C) Recovery ratio of the adhesive strength plotted as a function of healing time for the PRx-PB (20) gel, Pul-PB (20) gel, PRx-CC (20) gel, and pAAm (1) gel. Error bars represent the SD based on three independent experiments. Chem 2016 1, 766-775DOI: (10.1016/j.chempr.2016.09.013) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 3 Self-Healing of Film (A–C) Optical microscope images of a damaged PRx-PB (8) film (A), Pul-PB (8) film (B), and PRx-CC (8) film (C) measured with a laser microscope before and after heating at 60°C under humid conditions for 30 min. Scale bars, 100 μm. (D) Recovery ratio of the cross-sectional area of the scar plotted as a function of the healing time for the PRx-PB (8) film, Pul-PB (8) film, PRx-CC (8) film, and PRx-pAAm (1) film. Error bars represent the SD based on three independent experiments. Chem 2016 1, 766-775DOI: (10.1016/j.chempr.2016.09.013) Copyright © 2016 Elsevier Inc. Terms and Conditions

Scheme 1 Chemical Structure of the Gels (A) Schematic representation of HPPRx and HPPul used in this study. (B) Chemical structures of the PRx-PB (x) gel, Pul-PB (x) gel, PRx-CC (x) gel, and pAAm (x) gel used in this study. Here, x represents the mol % content of cross-linker units in the vinyl polymerization. Chem 2016 1, 766-775DOI: (10.1016/j.chempr.2016.09.013) Copyright © 2016 Elsevier Inc. Terms and Conditions