动态共价键是一种在外界刺激条件下可以可逆地断裂、生成和重组的一类特殊的共价键。动态共价键的键能处于共价键和非共价键之间，因此其具备独特的稳定性和可逆性，已经被广泛用于刺激响应性体系和动态共价材料等领域。含硒动态共价键包括二硒键，硒硫键和硒碲键等，它们的交换反应均表现出对光波长的依赖特性。尽管在过去的五年中，基于含硒化学键的动态材料被陆续报道，但利用含硒动态共价键的光波长响应特性，对材料进行的动态、温和、远程性能调控尚处于起步阶段。本论文主要围绕含硒动态共价键的光响应性展开，实现了对含硒高分子材料组装和自修复行为的远程温和调控，本论文主要取得了以下三方面的成果： 一、制备了含有硒硫键的光响应高分子囊泡，实现了其在不同光波长调控下的可控组装和解组装。使用紫外光诱导高分子之间发生硒硫交换反应，制备得到含有硒硫键的高分子囊泡，反应过程可以利用紫外-可见吸收光谱和凝胶渗透色谱（GPC）进行表征。通过对机理的研究，可以证实高分子间交换过程经历的是自由基机理。此外，可见光照射可以诱导高分子囊泡中的硒硫键发生断裂，进而使组装体解组装，为光波长响应动态材料的开发提供了思路。 二、制备了含硒高分子与碳纳米管的复合材料，利用激光作为可见光光源，实现了含硒高分子复合材料远程导电功能的快速修复。将二硒键引入交联聚氨酯材料，基于二硒键在可见光照下的动态交换反应，我们研究了该复合材料在可见光照射下的导电修复过程，以蓝色激光为光源，可以实现远程控制的导电自修复过程。可见光源的温和性可以减少利用紫外光或加热诱导自修复对高分子材料造成的损害，同时激光光源的远程传输特性也为材料的应用提供了众多的可能性。 三、基于二硒动态交换的光响应波长与水下蓝色窗口对应波长一致的特性，实现了含硒高分子材料的水下远程自修复。将二硒键引入疏水的高分子主链，赋予了材料水下激光诱导的远程修复功能。将这种材料应用在模拟水下输油管意外泄漏情况下的紧急修复场景中，实现了水下远程无接触的快速修复。
Dynamic covalent bonds are special kinds of covalent bonds that can break, form and recombine reversibly under external stimulations. The bond energy of the dynamic covalent bond is between the covalent bond and non-covalent bond, so it has unique stability and reversibility, and has been widely used in the construction of stimulus-responsive systems and the preparation of dynamic covalent materials. Selenium-containing dynamic covalent bonds consist of diselenide bonds (Se-Se), selenium-sulfur bonds (Se-S) and selenium-tellurium bonds (Se-Te). Their exchange reactions all show light wavelength dependence. Although the selenium-containing dynamic materials have been reported progressively in the past five years, achieving dynamic, mild and remote regulations to the properties of materials is still in its infancy when using the response to the visible light of selenium-containing dynamic bonds. This thesis studied the optical wavelength response of selenium-containing dynamic bonds in macromolecular assemblies, and then applied the characteristic of selenium-containing bonds in the remote self-healing materials. The main achievements of this paper are as follows: 1) The selenium-sulfur (Se-S) bond containing photoresponsive polymeric assemblies were prepared and their controllable assembly and disassembly induced by different wavelengths of light were achieved. UV light was used to induce selenium-sulfur exchange reaction between polymers to prepare Se-S bond containing polymeric assemblies. The reaction process was characterized by the UV-VIS absorption spectrum and the gel permeation chromatography (GPC). Through the study of the mechanism, it could be confirmed that the exchange reaction between polymers go through free radical mechanism. In addition, visible light could induce the breaking of the selenium-sulfur (Se-S) bonds in the polymer vesicles, and then the vesicles therefore disassembled, which gave the potential for developing light-wavelength responsive dynamic materials. 2) The selenium-containing composite materials with carbon nanotubes were prepared. Using a laser as a visible light source, the remote and rapid healing of conductive functions of selenium-containing polymeric composie materials was realized. Based on the dynamic exchange reaction of diselenide bonds under visible light, we have studied the conductivity healing process of composite materials under visible light by ? introducing diselenide bonds into crosslinked polyurethane materials. A remotely controlled conductivity self-healing process could be achieved by utilizing the blue laser as the light source. The gentleness of visible light sources could reduce the damage of polymer materials caused by ultraviolet light or heating induced self-healing. At the same time, the remote transmission characteristics of laser light sources also provide numerous possibilities for material applications. 3) The remote and underwater self-healing of selenium-containing polymeric materials was achieved based on the characteristic that the optical response wavelength of diselenide bonds is consistent with the corresponding wavelength of the underwater blue window. Introducing diselenide bonds into the hydrophobic polymer backbone endowed the material with a remote healing function induced by underwater laser irradiation. This material was applied in the emergency healing scenario, simulating the accidental leakage of the underwater oil pipeline which could be contactlessly and rapidly repaired at a distance.
