基于碳纳米管的三维结构构筑、复合材料制备与性能研究

发布时间：2018-05-05 00:11

本文选题：氮掺杂碳纳米管 + 三维多孔结构　；参考：《中国科学院研究生院(过程工程研究所)》2015年博士论文

【摘要】：碳纳米管(CNTs)是一类重要的一维碳质材料,由sp2/sp3杂化的碳原子构成,具有优异的电、力、光及热学特性。三维CNTs杂化材料具有相互连接的多孔结构、高的孔隙率、大的比表面积及高效的电子/声子传输通道,广泛应用于微电子、储能器件、导热材料及传感器等领域。目前,三维CNTs杂化材料的制备及性能研究已取得一定进展,常用的制备方法包括磁控溅射法、化学气相沉积法和溶胶凝胶法,但这些制备方法存在工艺比较复杂、成本昂贵等缺点。因此,寻找简便有效的方法制备结构和形貌可控的三维CNTs杂化材料,研究其组装机理及性能,对扩展CNTs的应用领域具有重要意义。本文以碳纳米管为基本构筑单元,通过不同组装方法制备了结构可控的三维CNTs杂化材料,并研究其组装机理、性能和应用。主要研究工作如下：1.三维氮掺杂碳纳米管(N-CNTs)海绵的制备及性能研究。本文通过混合酸氧化N-CNTs得到了水溶性的N-CNTs,然后采用冰模板法制备了三维N-CNTs海绵。该制备方法简单易行,并且可以通过控制冷冻温度实现海绵内部结构的调控。制备的N-CNTs海绵不仅具有低密度和高柔性,而且在不同形变下的Ⅰ-Ⅴ曲线呈非线性。通过控制N-CNTs海绵的机械形变实现了对其电阻的控制,可用于应变传感器。2.共价键连接的三维N-CNTs/Ag杂化海绵的制备及性能研究。为提高N-CNTs海绵的机械稳定性和其电阻对形变的灵敏度,本文采用超支化聚缩水甘油醚(HPG)作为桥梁将酸化的N-CNTs进行连接,同时HPG作为模板吸附Ag+,经过原位还‘原得到共价键连接的N-CNTs/Ag杂化粒子。N-CNTs/Ag杂化粒子通过冰模板法制备了柔性三维共价键连接的N-CNTs/Ag海绵,同时海绵内部孔径尺寸可通过冷冻温度进行调控。共价键作用提高海绵在压缩、振荡及弯曲形变下的结构稳定性,银纳米颗粒犹如联锁的纳米凸点增加海绵在形变过程中的接触面积。共价键和银纳米颗粒的协同作用使海绵在多次循环形变下保持高的稳定性和灵敏度,可用于应变传感器。3.金字塔形状N-CNTs/Ag杂化海绵的制备及性能研究。进一步提高N-CNTs/Ag海绵电阻对形变的灵敏度,本文通过冰模板法制备了金字塔形状的N-CNTs/Ag海绵。制备过程涉及等级结构设计,包括纳米尺度上杂化粒子的设计,微米尺度上多孔材料的设计,宏观尺度上金字塔形状的设计。根据逾渗理论调控海藻酸钠和N-CNTs/Ag两者的比例,实现了杂化海绵在应变作用下电阻的突变,3%应变下的灵敏度最高达15。通过上端电极结构设计和金字塔形状海绵／聚二甲基硅氧烷复合材料的结构设计,证实了铜箔电极和导电海绵界面间的接触电阻在金字塔形状海绵的高灵敏度方面发挥主导作用。对金字塔形状海绵进行封装不仅提高海绵的机械稳定性,而且降低其在压缩过程中的能量损耗和塑性形变。4.多功能氮掺杂碳纳米管基三维多孔材料的制备及性能研究。为丰富N-CNTs基多孔材料的功能性,通过层层自组装技术制备了多功能的三维多孔N-CNTs杂化材料(CHAs)。其中超支化聚酰胺胺可分散、稳定不同结构的功能性纳米粒子,提供阳离子层；海藻酸钠作为粘结剂将酸化的N-CNTs粘结在聚氨酯表面,提供阴离子层；聚氨酯海绵作为基体可有效地将CHAs受到的力转移到海绵骨架中。通过控制层层自组装的层数,得到了性能可控的CHAs。制备的CHAs具有高柔性、对功能性纳米粒子高的粘结力及优异的电阻-形变稳定性,可用于柔性导体、应变传感器和催化领域。5.多功能折叠结构单壁碳纳米管(SCNTs)复合纸的制备及性能研究。三维多孔材料受到足够大的载荷压缩,其内部骨架发生滑移且不能恢复,形成纸状结构。受此启发,本文通过高速剪切分散-冷冻干燥-压缩成型的技术制备了多功能折叠结构的单壁碳纳米管复合纸。内部的折叠多孔结构,使制备的复合纸在多次拉伸弯曲和压缩弯曲过程中展现出优异的电阻-形变稳定性；同时利用折叠纸的隔间结构吸收储存石蜡制备相变材料,实现水滴在其表面接触角的控制。
[Abstract]:Carbon nanotube (CNTs) is an important one of the important one-dimensional carbon materials, composed of sp2/sp3 hybrid carbon atoms, with excellent electrical, force, light and thermal properties. The three-dimensional CNTs hybrid materials have a porous structure connected with each other, high porosity, large specific surface area and high efficient electric / phonon transmission channels, widely used in microelectronic and energy storage devices. At present, some progress has been made in the preparation and performance of three-dimensional CNTs hybrid materials. The commonly used preparation methods include magnetron sputtering, chemical vapor deposition and sol-gel method, but these methods are complicated and costly. Therefore, a simple and effective method is found. The mechanism and properties of three-dimensional CNTs hybrid materials with controllable structure and morphology are very important for the application of CNTs. In this paper, carbon nanotube is used as the basic building unit to prepare three dimensional CNTs hybrid materials with controllable structure by different assembly methods. The mechanism, properties and applications of the structure are studied. As follows: 1. preparation and properties of three-dimensional nitrogen doped carbon nanotube (N-CNTs) sponge. In this paper, a water-soluble N-CNTs was obtained by oxidizing N-CNTs with mixed acid, and then a three-dimensional N-CNTs sponge was prepared by the ice template method. The preparation method was simple and easy to control the internal structure of the sponge by controlling the freezing temperature. The N-CNTs sponges not only have low density and high flexibility, but also the I-V curves of different deformation are nonlinear. By controlling the mechanical deformation of N-CNTs sponges, the resistance is controlled. The preparation and performance study of the three-dimensional N-CNTs/Ag hybrid sponge with the strain sensor.2. covalent bond can be used to improve the mechanical properties of the N-CNTs sponge. The sensitivity of stability and its resistance to deformation is used in this paper to connect the acidified N-CNTs with hyperbranched polyglycidyl ether (HPG) as a bridge, while HPG is used as a template to adsorb Ag+, and the N-CNTs/Ag hybrid particle.N-CNTs/Ag hybrid particles connected by the original covalent bond in situ are prepared by the ice template method to prepare the flexible three-dimensional covalent bond. The size of the cavern can be controlled by the freezing temperature. The covalent bond action improves the structural stability of the sponge under the compression, oscillation and bending deformation. The silver nanoparticles like the interlocked nano bumps increase the contact area of the sponge during the deformation process. The synergistic effect of covalent and silver nanoparticles is enhanced. The high stability and sensitivity of the sponge can be maintained under the repeated cyclic deformation. It can be used in the preparation and performance study of strain sensor.3. Pyramid shaped N-CNTs/Ag hybrid sponge. The sensitivity of the N-CNTs/Ag sponge resistance to deformation is further improved. In this paper, the Pyramid shape N-CNTs/Ag sponge is prepared by the ice template method. The design of hierarchical structure, including the design of hybrid particles on nanoscale, the design of porous materials on micron scale, the design of Pyramid shape on the macro scale, and the proportion of alginate and N-CNTs/Ag based on percolation theory, realized the mutation of the electrical resistance of the hybrid sponge under strain action, and the sensitivity of 3% strain was up to 15. through the strain. The structure design of the upper end electrode and the structural design of the Pyramid shape sponge / poly two methyl siloxane composite material proved that the contact resistance between the copper foil electrode and the conductive sponge interface plays a leading role in the high sensitivity of the Pyramid shape sponge. The entry package for the Pyramid shape sponge not only improves the mechanical stability of the sponge. In addition, the preparation and properties of.4. multi-functional nitrogen doped carbon nanotube based three-dimensional porous materials in the compression process were reduced and the properties of the multi-function N-CNTs based porous materials were enriched. The multi-functional three-dimensional porous N-CNTs hybrid material (CHAs) was prepared by layer self-assembly technology, in which the hyperbranched polyamines were used. The functional nanoparticles of different structures can be dispersed and stable. The cationic layer is provided, and sodium alginate is used as binder to bond the acidified N-CNTs to the surface of the polyurethane and provide the anion layer. As a matrix, the polyurethane sponge can effectively transfer the force of CHAs to the sponge skeleton. The controllable CHAs. CHAs has high flexibility, high cohesive force to functional nanoparticles and excellent resistance deformation stability. It can be used in the preparation and study of the flexible conductor, strain sensor and the.5. multi-function folded structure of single wall carbon nanotube (SCNTs) composite paper in the field of catalysis. The three-dimensional porous material is subjected to large enough load. In this paper, a multi function folded structure of single wall carbon nanotube composite paper was prepared by high-speed shear dispersion freeze drying compression molding. The internal folding porous structure made the prepared composite paper bending and compressing the bending process many times. The excellent resistance deformation stability is displayed, and the paraffin wax is used to prepare the phase change material by using the partition structure of the folded paper to realize the control of the contact angle of the water droplet on its surface.

【学位授予单位】：中国科学院研究生院(过程工程研究所)
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ127.11;TB383.1

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