基于电纺纤维网络构筑的导电高分子复合材料及其应变敏感性能研究

发布时间：2018-08-03 18:04

【摘要】：导电高分子复合材料(CPCs)的结构及性能调控是高分子材料领域的研究热点之一,近来得到研究者的广泛关注。CPCs广泛应用于电阻式应变传感器,在电子皮肤、人体运动监控和材料破坏行为监测等领域应用前景广阔。本文基于CPCs的结构性能调控及应变敏感行为研究,提出了含预制导电功能化静电纺丝纤维网络的CPCs基应变传感器的制备方法,研究了该材料的形态结构特征及拉伸敏感行为,主要成果如下:1、含碳纳米管(CNTs)修饰静电纺丝纤维网络的CPCsCNTs具有优异的电学和机械性能,是制备CPCs的重要填料。然而,传统熔融或溶液共混法很难制备出兼具良好电学、机械及应变敏感性能的CNTs填充型CPCs。导致该现象的机制主要是因为CNTs填充型CPCs用作应变传感器时,为了获得重复性优异的响应信号,体系所需CNTs含量通常较高,而在高含量下,CNTs极易团聚并最终导致机械性能的损失。因此,如何制备出综合性能优异的CPCs基应变传感器仍是该领域的一个挑战。本文提出了一种新颖的CNTs填充型CPCs的制备方法,具体是指采用高分子溶液浇筑法将预制的CNTs修饰的尼龙6(PA6)电纺纤维膜嵌入到聚乙烯醇(PVA)基体内,通过该方法容易获得电学、机械及应变敏感性能均优的CPCs基应变传感器。我们通过超声法将CNTs修饰在PA6电纺纤维表面,预先构筑具有导电功能的电纺纤维网络,并研究了CNTs-PA6导电纤维膜的电学、力学和拉伸敏感性能,CNTs在PA6纤维表面的特殊分布状态,除有效提高复合材料的电导率外,还能改善了PA6纤维及PVA基体间的界面结合,从而为基体材料拉伸性能的提高提供了可能。增加CNTs-PA6纤维膜层数能够进一步改善复合材料的电性能,相应结果为CNTs-PA6/PVA复合材料的拉伸敏感性能调控提供了实验依据。但会对材料力学性能产生不利影响,最终我们择优选择含两层CNTs-PA6纤维膜的复合材料(CNTs-PA62/PVA)作为研究对象。该复合材料的单轴拉伸响应曲线呈阶段式变化,每阶段分别对应不同的结构破坏模型,我们对相应模型进行了详细分析。循环拉伸测试结果表明,CNTs-PA62/PVA复合材料在不同的变形水平下表现出易区分的响应行为,如循环最大响应度(Rmax/R0)偏移程度及肩峰峰强之间存在较大差异,这些可以作为自诊断指标分析该复合材料内部结构破坏程度。此外,多次拉伸/回复循环和预拉伸处理能显著改善复合材料拉伸响应行为的可重复性。2、含炭黑(CB)修饰静电纺丝纤维网络的CPCsCB具有较低的维度(零维),其构建的导电网络对外场刺激往往具有灵敏的响应行为,因此,我们利用CB代替CNTs,采用相同的制备工艺制得含一层纤维膜的CB-PA6/PVA复合材料,详细研究了该复合材料的拉伸响应行为。研究结果表明CB-PA6/PVA复合材料具有稳定的响应信号和良好的可重复性及耐久性,适宜作为应变传感器使用。我们还发现CB和CNTs结构的不同会导致导电网络构筑方式的不同,从而使相应复合材料体系的拉伸敏感行为之间存在较大差异。本研究对制备综合性能优异的应变传感器具有重要的指导作用。
[Abstract]:The structure and performance regulation of conductive polymer composites (CPCs) is one of the hot topics in the field of polymer materials. Recently, the widespread concern of the researchers is that.CPCs is widely used in the resistance strain sensor, and is widely used in the fields of electronic skin, human motion monitoring and material destruction monitoring. This paper is based on the structure of CPCs. The preparation method of CPCs based strain sensor containing prefabricated conductive functionalized electrostatic spinning fiber network is proposed. The morphological structure characteristics and tensile sensitivity of the material are studied. The main results are as follows: 1, the CPCsCNTs with carbon nanotube (CNTs) modified electrospun fiber network is excellent. Electrical and mechanical properties are important fillers for the preparation of CPCs. However, it is difficult to produce CNTs filled CPCs. with good electrical, mechanical and strain sensitivity by traditional melting or solution blending. The mechanism of this phenomenon is mainly because the CNTs filled CPCs is used as a strain sensor, in order to obtain an excellent response signal with excellent repeatability. The required CNTs content is usually high, and at high content, CNTs is very easy to reunite and eventually lead to the loss of mechanical properties. Therefore, how to prepare a CPCs based strain sensor with excellent comprehensive properties is still a challenge in this field. A novel method of preparing CNTs filled CPCs is proposed in this paper, which refers to the use of polymer solution. The prefabricated CNTs modified nylon 6 (PA6) electrospun fiber membrane was embedded in the matrix of polyvinyl alcohol (PVA). By this method, the CPCs based strain sensor with excellent electrical, mechanical and strain sensitive properties was easily obtained. We modified CNTs on the surface of PA6 electrospun fiber by ultrasonic method, and prefabricated the electrical fiber network with conductive function in advance. The electrical, mechanical and tensile properties of the CNTs-PA6 conductive fiber film are also studied. The special distribution of CNTs on the surface of PA6 fiber can improve the interfacial bonding between the PA6 fiber and the PVA matrix, in addition to effectively improving the conductivity of the composite, thus providing the possibility of increasing the tensile energy of the matrix material. The increase of the CNTs-PA6 fiber film layer is added. The number can further improve the electrical properties of the composites, and the corresponding results provide the experimental basis for the control of the tensile sensitivity of CNTs-PA6/PVA composites. However, it will have an adverse effect on the mechanical properties of the materials. Finally, we choose the optimum selection of the composite material containing two layers of CNTs-PA6 fiber membrane (CNTs-PA62/PVA) as the research object. The response curves of the uniaxial tension are phased, and each stage corresponds to the different structural failure models. The corresponding model is analyzed in detail. The cyclic tensile test results show that the CNTs-PA62/PVA composite exhibits a distinct response behavior at different deformation levels, such as the maximum cyclic response degree (Rmax/R0) offset. There is a large difference between the degree and the peak intensity of the acromion, which can be used as a self diagnostic index to analyze the internal structural damage of the composite. Furthermore, the repeatability of the tensile response behavior of the composites can be significantly improved by the multiple tensile / recovery cycle and pretension treatment, and the CPCsCB of the carbon black (CB) modified electrospun fiber network has a lower CPCsCB. In the dimension (Ling Wei), the conductive network it constructs often has a sensitive response to the external field stimulation. Therefore, we use the CB instead of CNTs to produce a CB-PA6/PVA composite containing a layer of fiber membrane by the same preparation process. The tensile response behavior of the composite is studied in detail. The results show that the CB-PA6/PVA composite has a good response. Stable response signals and good repeatability and durability are suitable for use as strain sensors. We also found that the difference in the structure of CB and CNTs leads to the difference in the construction mode of the conductive network, which makes the tensile sensitivity of the corresponding composite system greatly different. Sensors have an important guiding role.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TQ340.64

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