Cracks formed in materials can influence the performances and shorten their lifetime. Self-healing materials can repair cracks caused by mechanical damage using external stimuli, which increases their safety, extend their service life, and can save renovation costs. In this work, a novel thermo-responsive linear Diels-Alder polyurethane (DAPU) and reduced tungsten oxide (WO_3−x) (W-DAPU) is developed for the first time. Its near-infrared (NIR) light-induced self-healing properties are evaluated using qualitative optical observation and quantitative tensile measurements. The NIR light-induced self-healing and photothermal conversion property of W-DAPU is also systematically investigated. The results show that linear DAPU has an excellent thermo-reversible self-healing efficiency of 94.8% and heals within 6 s due to the presence of a DA bond. In addition, the W-DAPU has a self-healing efficiency of 83.2% with outstanding photothermal conversion. This study paves the way to design and fabricate stimuli-responsive nanocomposite materials for various applications.

中文翻译：

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基于Diels-Alder反应的NIR光刺激自修复还原氧化钨/聚氨酯纳米复合材料

材料中形成的裂纹会影响性能并缩短其使用寿命。自修复材料可以利用外部刺激修复机械损伤造成的裂缝，增加其安全性，延长其使用寿命，并可以节省翻新成本。在这项工作中，一种新型的热响应线性 Diels-Alder 聚氨酯 (DAPU) 和还原氧化钨 (WO _{3− x}) (W-DAPU) 是首次开发。使用定性光学观察和定量拉伸测量来评估其近红外 (NIR) 光诱导的自愈特性。还系统地研究了 W-DAPU 的 NIR 光诱导自愈和光热转换特性。结果表明，线性 DAPU 具有 94.8% 的优异热可逆自修复效率，并且由于 DA 键的存在而在 6 s 内愈合。此外，W-DAPU 具有 83.2% 的自愈效率和出色的光热转换。这项研究为设计和制造用于各种应用的刺激响应纳米复合材料铺平了道路。