利用喷涂组装的仿生层层复合结构的设计，构建与性能研究

发布时间：2018-03-09 15:06

本文选题：仿生　切入点：喷涂　出处：《合肥工业大学》2017年博士论文　论文类型：学位论文

【摘要】：通过结构优化设计实现功能性材料的力学强化,从而更好满足相关领域的实际应用需要一直是当前材料科学领域的研究热点。近年来,随着表征手段的提高,生物结构材料的优异的机械性能与其微观结构之间的关系得到广泛关注和深入研究。例如贝壳不仅具有光彩夺目的结构色和优异的机械力学性能,其高度有序的“砖-泥”微观层状结构也被系统研究,并成为高强度功能材料最受欢迎的设计模型之一。本论文以贝壳等生物结构材料为模型,选用合适的一维和二维纳米结构单元,采用喷涂层层自组装的方法成功制备出几种具有优异力学性能的仿生多层组装复合膜,同时揭示其力学性能与微观结构和界面作用之间的关系。主要研究结果包括以下三个方面:(1)以银纳米线和巯基壳聚糖作为结构单元,通过喷涂层层组装技术制备一系列仿生多层组装银纳米线-巯基壳聚糖复合膜。利用银与巯基之间形成的银-硫共价键可以优化界面作用力,进而增强膜的力学性能。相对于纯的巯基壳聚糖膜,当银纳米线的比例达到60 wt%时其拉伸应力和杨氏模量增加了 3.9和11.7倍,且远远大于银纳米线-壳聚糖膜、其他纳米粒子与壳聚糖形成的复合膜以及银纳米线与其他有机物形成的复合膜的力学性能。此外,60 wt%银纳米线-巯基壳聚糖复合膜拥有良好的抗疲劳性。银-硫键对银纳米线-巯基壳聚糖复合膜的增强效应将来也有望用于其他高性能复合膜的制备。(2)芳纶纤维具有优异的机械性能、耐高温和化学惰性等,因此是一种重要的高性能复合材料,已经被广泛用于航空航天,造船和军工领域。由芳纶纤维剥离获得的均匀的芳纶纳米纤维是一种新型的结构材料组装基元。我们基于一维的芳纶纳米纤维和二维的云母粉,利用喷涂层层组装技术制备一系列复合膜。利用一维和二维结构基元界面间形成的多重氢键和“砖-泥”微观层状结构显著提高了复合膜的力学性能。40 wt%无机掺杂比例的芳纶纳米纤维复合膜具有良好的柔韧性和透光性,而且其力学性能得到显著增强,拉伸应力,杨氏模量和韧性相对于纯的芳纶纳米纤维膜分别增强了 1.7, 3.2和1.8倍。(3)基于纳米云母片和海藻酸钠为结构单元,通过喷涂层层组装技术成功制备了一系列仿贝壳多层组装的复合膜。利用纳米云母片和海藻酸钠之间的静电和氢键优化界面作用力,该复合膜优化后的拉伸应力和杨氏模量分别达到205 MPa和18.4 GPa。该膜的透光性良好,同时具有很好的防火阻燃性能。该复合膜还可以涂层到聚酯薄膜基底上,实现对于基底材料的功能改性。
[Abstract]:The mechanical strengthening of functional materials through structural optimization design is always a hot research topic in the field of material science, which can better meet the practical application needs of related fields. In recent years, with the improvement of the means of characterization, it has been a hot topic in the field of material science. The relationship between the excellent mechanical properties of biomaterials and their microstructure has been extensively studied. For example, shells not only have brilliant structural colors and excellent mechanical and mechanical properties, Its highly ordered "brick-mud" microstructure has also been systematically studied, and has become one of the most popular design models for high-strength functional materials. Several biomimetic multilayer composite films with excellent mechanical properties were successfully prepared by spraying layer by layer self-assembly with suitable one-dimensional and two-dimensional nanostructure units. The main results include the following three aspects: 1) silver nanowires and mercapto chitosan were used as structural units. A series of biomimetic multilayer assembled silver nanowires and mercapto chitosan composite films were prepared by spraying layer by layer assembly technique. The interface force can be optimized by using the silver-sulfur covalent bond formed between silver and thiol. Compared with pure thioglycol-chitosan membrane, the tensile stress and Young's modulus of silver nanowires increased 3.9 and 11.7 times when the ratio of silver nanowires reached 60 wt%, and was much larger than that of silver nanowires / chitosan membranes. The mechanical properties of the composite films formed by other nanoparticles and chitosan and silver nanowires and other organic compounds were obtained. In addition, the composite films of 60 wt% silver nanowires and mercapto chitosan had good fatigue resistance. The enhancement effect of bond on silver nanowires / mercapto chitosan composite membrane is expected to be used in the preparation of other high performance composite membranes. Because of its high temperature resistance and chemical inertia, it is an important kind of high performance composite material, which has been widely used in aerospace industry. Shipbuilding and military industries. Homogeneous aramid nanofibers derived from aramid fibers are a new structural material assembly unit. We are based on one-dimensional aramid nanofibers and two-dimensional mica powder. A series of composite films were prepared by spraying layer by layer assembly technique. The mechanical properties of the composite films were significantly improved by using the multiple hydrogen bonds formed between the interface of one-dimensional and two-dimensional structural elements and the microstructure of "brick-mud" microlayers. The mechanical properties of the composite films were improved significantly. 40 wt% inorganic admixture was used. The hybrid aramid nanofiber composite film has good flexibility and light transmittance. The tensile stress, Young's modulus and toughness were increased by 1.7,3.2 and 1.8 times than those of pure aramid nanofiber membranes, respectively.) based on nano-mica and sodium alginate as structural units, the mechanical properties of the film were significantly enhanced, and the tensile stress, Young's modulus and toughness were increased by 1.7,3.2 and 1.8 times as compared with the pure aramid nanofibers, respectively. A series of composite films were successfully prepared by spraying layer by layer assembly technique. The interface forces of electrostatic and hydrogen bonding between nano-mica and sodium alginate were optimized. The tensile stress and Young's modulus of the composite film are 205GPA and 18.4 GPa. the film has good transmittance and good fire resistance and flame retardancy. The composite film can also be coated on the substrate of polyester film. The functional modification of the substrate is realized.
【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB383.2

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