受蜻蜓翅膀启发，基于导电石墨烯薄膜的超分子弹性体，用于轮胎和智能监控等

摘要：蜻蜓翅膀从微观到宏观都具有独特的分层结构，因而具有极高的强度、韧性和抗疲劳性。受此启发，本文，南京林业大学罗艳龙副教授团队在《ADVANCED FUNCTIONAL MATERIALS》期刊发表名为“Dragonfly Wing-Inspired Retic

1成果简介

蜻蜓翅膀从微观到宏观都具有独特的分层结构，因而具有极高的强度、韧性和抗疲劳性。受此启发，本文，南京林业大学罗艳龙副教授团队在《ADVANCED FUNCTIONAL MATERIALS》期刊发表名为“Dragonfly Wing-Inspired Reticular Hierarchical Structure Enables Strong and Tough Supramolecular Elastomers”的论文，研究将错配超分子相互作用（MMSIs）引入到动态酰基缩氨基脲基团中，在SPUU-DS弹性体中构建了一个软段和硬段相互连接的混合网络。

这种具有密集氢键阵列的设计实现了卓越的机械性能：断裂时的真实应力为 1.1 GPa，与典型蜘蛛丝（0.8-1.5 GPa）相当；韧性为 325.54 MJ m-3，是典型蜘蛛丝（≈160 MJ m-3）的两倍；断裂能为 232.83 kJ m-2，超过了许多金属和合金。此外，通过将 SPUU-DS 与导电石墨烯薄膜集成，还开发出一种具有 “汉堡包 ”结构的监测装置。将该装置置于轮胎内，可将轮胎的抗穿刺能力提高约两倍。通过将阻力信号与穿刺角度相关联，该系统能够检测轮胎上不同位置的损伤，从而及时修复损伤，防止交通事故的发生。这种新颖的仿生方法受到蜻蜓翅膀的启发，为设计具有优异机械性能的可愈合弹性体提供了宝贵的启示。

2图文导读

图1、a) The structure of a dragonfly wing. b) The enhancement of mechanical properties in elastomers, achieved through the synergistic interaction between rigid and flexible supramolecular chain segments. c) The molecular design of an elastomer incorporating either an aliphatic or aromatic amide, where the yellow sections represent soft segments and the blue and green lines denote hard segments of different compositions.

图2、a) Synthesis route of SPUU elastomers. b) Atomic modeling of SPUU-D2S1(1.6) elastomer for molecular dynamics (MD) simulations (pink represents the hard segment). c) Comparative cohesive energy density (CED) of SPUU-DS elastomers. d) Interaction energy (Es-h) between the soft and hard segments of the three systems.

图3、a) UV transmission spectra of the elastomers. b) Image captured with an SPUU-D2S1(1.6) film placed over a cell phone camera. Variable temperature FTIR spectra of c) the ν(N-H) vibrational region and d) ν(C═O) vibrational region, heated from 30 to 120 °C. e) Synchronized and f) asynchronous maps of SPUU-D2S1(1.6) in the region 1900–1500 cm−1 FTIR spectra. The red, white, and blue regions represent positive, zero, and negative correlation intensities. g) Schematic representation of four types of individual hydrogen bonds, including urea-urea interactions, urea-urethane interactions, urethane-urethane interactions, and urethane-urea interactions. h) FTIR spectrum of SPUU-D2S1 (1.6) in the region of C═O stretching vibration.

图4、a) XRD images of SPUU-D2S1(1.6) in its original state and stretched 200%, 400%, and 600% states. XRD images of b) SPUU-D2S1(1.8) and (c) SPUU-D2S1(1.4) in its original state and stretched 200% and 400% states. d) AFM test image of SPUU-D2S1(1.6). e) SAXS images of three elastomers. f) Loss factor (tan δ) versus temperature for the three elastomers. g) Normalized stress relaxation curves of SPUU-D2S1(1.6) elastomers in the range of 70–100 °C. h) Normalized stress relaxation curves at 100 °C for three elastomers. i) Relaxation activation energies (Ea) of the three elastomers.

图5、a) Engineering stress–strain curves for SPUU-DS elastomers. b) True stress–strain curve for SPUU-DS elastomers. c) Comparison of toughness of SPH and DABA elastomers with different molar ratios. d) The SPUU-DS sample (0.3034 g) is capable of lifting a 6.0 kg weight. e) Schematic diagram of puncture resistance. f) Typical engineering stress–strain curves for unnotched and notched specimens at a tensile speed of 50 mm min−1. g) Comparison of fracture energies of SPUU-D2S1(1.6) elastomers, previously reported polymer elastomers, and metals and alloys.[28, 34, 29, 35-37] h) Tensile tests at 500% strain in a continuous loading-unloading cycle. i) Photographs of the original, slender, and fixed samples.

图6、a) Typical engineering stress–strain curves of the SPUU-D2S1(1.6) sample before and after different recovery times. b) Photograph showing the healed SPUU-D2S1(1.6) sample lifting a 5 kg weight. c) Photographs of SPUU-D2S1(1.6) samples before and after recycling. d) FTIR spectra of the SPUU-D2S1(1.6) sample before and after different times of recovery. e) UV–vis spectra of SPUU-D2S1(1.6) samples before and after recycling at five different times. f) Typical engineering stress-strain curves of SPUU-D2S1(1.6) samples before and after recycling for different times. g) Self-healing mechanism of SPUU-D2S1(1.6) sample.

图7、a) Illustration of the application of SPUU-D2S1(1.6) elastomer as a smart protection detection layer. b) Force-displacement curves obtained from the puncture test. Signal maps of the puncture protection detection layer at various angles: c) 30°, d) 45°, e) 60°, f) 90°, and g) 120°. R0 is the original resistance of S-G-S device and ΔR is the change in resistance after the S-G-S has been punctured.

3小结

总之，我们受蜻蜓翅膀的启发，开发出了一种超分子弹性体 SPUU-D2S1(1.6)。这种弹性体兼具高强度、韧性和出色的能量耗散性能。通过加入动态 ASCZ 和调整 MMSIs，SPUU-D2S1(1.6) 表现出了出色的自愈性和可回收性，使其成为一种具有可持续应用前景的材料。

我们精心设计了超分子弹性体的分子结构。首先，我们选择了含有酰肼的扩链剂，以便在硬域中形成多个氢键。然后，我们调整了超分子软段与硬段的比例，以实现 MMSIs。这种设计形成了一种网状结构，其中软段和硬段的分布模仿了蜻蜓翅膀的网络。这样就产生了一种高度透明的超分子弹性体，其断裂时的真实应力为 1.1 GPa，与典型的蜘蛛丝相当，而韧性（325.54 MJ m-3）则是典型蜘蛛丝的两倍。SPUU-D2S1(1.6) 弹性体的抗拉强度高达 49.52 兆帕，断裂能为 232.83 kJ m-3，甚至高于合金和金属的断裂能，使弹性体即使在切割或开裂后仍具有高度的可靠性和耐久性。此外，通过将 SPUU-D2S1(1.6) 与导电石墨烯薄膜相结合，还开发出一种具有 “汉堡包 ”结构的监测装置。这种装置不仅提高了轮胎的性能，还为智能监测和维修系统开辟了新的可能性，具有广泛的应用潜力。

文献：