【作者】 李政；

【导师】 从怀萍；

【作者基本信息】 合肥工业大学 ， 化学工程与技术， 2021， 硕士

【摘要】 水凝胶由于其高度的生物相容性和兼具流体与固体的性能而被广泛的用于生物医学、柔性传感、能源储存等广泛的领域。然而,随着材料科学的不断发展,对材料提出了更高的要求。对于水凝胶来说,其单一的性能(弱的机械强度、高温失水、低温冻结、有机溶剂相分离等)已经无法满足人类的需求。极端环境相容的纳米复合水凝胶越来越成为材料科学家的研究热点。基于此,本文通过穿插异质二重网络、乳液杂化交联等策略构建了高强度、超弹性、极端环境相容的纳米复合水凝胶。本文具体研究内容如下:1.采用银纳米线,丙烯酰胺,N,N-二甲基双丙烯酰胺,过二硫酸钾和四甲基乙二胺进行取向冷冻,放置一夜,形成均质多孔银纳米线-聚合物壁结构的超弹性水凝胶。紧接着以该超弹性水凝胶为基底,丙酮脱水,通过光引发剂907形成银-硫配位键对银纳米线-聚合物壁进行修饰,最后通过油性前体溶液浸泡,紫外光聚形成穿插异质网络的有机水凝胶压力传感器。该有机水凝胶体现出优异的超弹性、抗疲劳性、耐低温、抗油溶胀性能。在达到70%的压缩形变下可以很好地恢复到其原始形状,甚至在-50 ~oC,不同的油性环境中可以维持着较高的加载-卸载循环,优异的压敏性能。2.采用氨丙基封端的聚二甲基硅氧烷在十二烷基硫酸钠的作用下,辅以一定的温度在水相中形成均质的乳液微球。缓慢滴加氯金酸溶液,在一定的温度下围绕着微球周围原位生长金纳米颗粒,通过N,N-双(丙烯酰)胱胺对“核壳”进行改性构建乳液杂化大分子交联剂,最后参与构建水凝胶三维网络,形成多功能的原位还原杂化水凝胶。该杂化水凝胶显示出优异的机械强度、超弹性、卓越的极端环境适应性;在达到3000%的拉伸条件下(拉伸应力2.3 MPa)恢复到原长,在-20～90 ~oC可以保持机械弹性,在有机溶剂中可以自适应且高效的光热转化。因此,该复合水凝胶材料在更为广阔的领域有着良好的应用前景。更多还原

【Abstract】 Hydrogels are widely used in biological engineering,flexible sensing,energy storage and other fields due to their high biocompatibility and the properties of both fluid and solid.However,with the development of material science,higher requirements are put forward for materials.For hydrogels,their single properties(weak mechanical strength,high temperature water evaporation,low temperature freezing,organic solvent phase separation,etc.)have been unable to meet the needs of human beings.Extreme environment-compatible nanocomposite hydrogels have becoming the research focus of material scientists.Based on this,nanocomposite hydrogels with high strength,super elasticity and extreme environment compatibility were constructed by dual hetero-network and emulsion hybrid crosslinking strategies.The specific research contents of this paper are as follows:1.Silver nanowires,acrylamide,N,N-dimethyldiacrylamide,potassium perdisulfate and methylethylenediamine were used for orientation freezing and placed overnight to form homogeneous porous silver nanowires with polymer wall structure of ultra-elastic hydrogel.Then the ultra-elastic hydrogel was used as the substrate,acetone was dehydrated,silver nanowires and polymer walls were modified by the formation of silver-sulfur coordination bonds by the light initiator 907,and finally the organic hydrogel pressure sensor with heterogeneous network was formed by the immersion of oily precursor solution and ultraviolet light polymerization.The organic hydrogel exhibits excellent super-elasticity,fatigue resistance,low temperature resistance,and oil expansion resistance.It can be well restored to its original shape under compression deformation of 70%.It can maintain a high load-unloading cycle even in-50 ~oC and different oil environment,and has excellent pressure sensitivity.2.Homogeneous micro-spheres are formed in the aqueous phase by using amino-terminated polydimethylsiloxane under the action of sodium dodecyl sulfate and with a certain temperature.The gold nanoparticles were formed in situ around the microspheres at a certain temperature by slowly dropping the chloric acid solution,and the emulsion hybrid macromolecule crosslinking agent was constructed by modifying core-shell with N,N-bis(acrylyl)cystamine.Finally,the hydrogel three-dimensional network was constructed to form multifunctional nanocomposite hydrogels.The nanocomposite hydrogels show excellent mechanical strength,super elasticity,good adaptability to extreme environments.They are restored to their original length under tensile condition of 3000%(2.3 MPa)and could maintain excellent mechanical elasticity at-20～90 ~oC,show excellent performance in resisting poor solvents and good photothermal conversion capacity.Therefore,the nanocomposite hydrogel material has a good application prospect in a broader field.更多还原