【作者】 肖光；

【导师】 王一奇；

【作者基本信息】 大连理工大学 ， 机械工程（专业学位）， 2021， 硕士

【摘要】 碳纳米管具有优异的力学、电学和热学性能,是开发导电纤维、构建电子智能纺织品导电线路的理想材料。然而碳纳米管在组装过程中难以形成良好的电子传输通路,使得目前浮动催化技术、阵列纺丝技术和湿法纺丝技术制备的碳纳米管纤维的电导率较低,无法满足实际应用的需要。虽然科研工作者基于这些纺丝技术提出了相关的改善手段,但是也存在效果不显著,稳定性弱与成本较高等问题。为此,本论文基于湿法纺丝技术开发了一种改善碳纳米管纤维导电性能的新工艺手段,提出利用纺丝原液设计、银化学沉积反应、热压处理和工艺参数的优化等过程制备一种高电导率的碳纳米管/银复合纤维,并成功构建了性能稳定的织物导电线路。论文的主要研究内容及结果如下:（1）采用高压均质法制备了包含胆酸钠（SC）、羧甲基纤维素钠（CMC）和单壁碳纳米管（SWNT）的纺丝原液,并采用透射电子显微镜、紫外-可见光-近红外光谱仪对SWNT的分散性进行了表征,结果表明CMC含量的变化会影响纺丝原液中碳纳米管的分散状态,少量CMC的存在有利于SWNT的分散,而过量CMC会对SWNT的分散状态产生不利影响。旋转流变仪测试结果表明CMC含量的增加会增大纺丝原液的粘度,但是不会改变其剪切变稀的非牛顿流体特性。（2）采用万能材料试验机和数据采集器对初始纤维的性能进行了测试,并采用扫描电子显微镜对纤维的形貌进行了表征分析,结果表明CMC的存在影响初始纤维本身的导电和力学性能,一定含量范围内CMC的存在可以增强SWNT之间的相互作用,从而提升纤维的各项性能,而含量过高则会阻碍纤维中电子的传输。采用超精密天平测算了银沉积后复合纤维的线密度,结果显示CMC的存在有利纤维对银的吸附。采用数据采集器测试了热压处理后复合纤维的电导率,结果表明CMC浓度为2 mg/m L时复合纤维电导率最高,可达5.9×10⁶ S/m。（3）优化了硝酸银（AgNO₃）浓度、沉积反应时间、SWNT浓度以及热压处理的压力等工艺参数,结果表明当SWNT浓度为6 mg/m L,AgNO₃浓度为0.6 mol/L,沉积反应时间为40 min,压强为10 MPa条件下热压处理后复合纤维的性能较好,其电导率可达1.9×10⁷S/m,拉伸强度可达80.6 MPa。（4）对复合纤维构建的织物导电线路进行了应用演示和环境实验测试,结果显示复合纤维构建的导电线路具有良好的机械稳定性、耐清洗性、环境稳定性和时效性。更多还原

【Abstract】 Carbon nanotubes have excellent mechanical,thermal and electrical properties,and are ideal materials for developing conductive fibers and constructing conductive circuits of electronic intelligent textiles.However,it is difficult to form a good electron transport path during the assembly process of carbon nanotubes,so the carbon nanotubes prepared by floating catalyst technique,array spinning technique and wet spinning technique are often of low conductivity,which cannot meet the needs of practical applications.Although researchers have proposed relevant improvement measures based on these spinning technologies,there are still problems such as insignificant effect,weak stability and high cost.To solve these problems,a new method based on the wet spinning technique was developed in this paper to improve the electrical conductivity of carbon nanotube fibers,and a novel carbon nanotube/silver composite fiber with high conductivity was prepared by the process of spinning solution design,silver chemical deposition,hot-pressing treatment and process parameters optimization.After optimizing the process parameters,the conductive circuit of the textiles with stable performance was also successfully constructed.The main research contents and results of this paper are shown as follows:(1)The spinning solution containing sodium cholate(SC),sodium carboxymethyl cellulose(CMC)and single-walled carbon nanotubes(SWNT)was prepared by high pressure homogenization method,and dispersion state of SWNT was characterized by transmission electron microscopy and UV-VIS-NIR spectroscopy.The results showed that the change of CMC content can affect the dispersion state of SWNT in the spinning solution,and a small amount of CMC was beneficial to the dispersion state of SWNT,while an excessive amount of CMC had a negative effect on the dispersion state of SWNT.The results of rotary rheometer test showed that the increase of CMC content can improve the viscosity of spinning solution,but didn’t change the non-Newtonian fluid characteristics of shear thinning.(2)The properties of the initial fibers were tested by a universal material tester and a data collector,and the morphology of the fibers was characterized by a scanning electron microscope.The results showed that the presence of CMC affects the electrical conductivity and mechanical properties of the initial fibers.The presence of CMC in a certain content range could enhance the interaction between SWNT and improve the properties of the fibers,while the excessive content would hinder the electron transport in the fibers.Ultra-precision balance was used to calculate the linear density of the composite fibers after silver deposition.The results showed that the presence of CMC was beneficial to the adsorption of silver.The electrical conductivity of the composite fibers after hot-pressing was measured by using a data collector.The results showed that the electrical conductivity of the composite fibers was the highest when the concentration of CMC was 2 mg/m L,which could reach 5.9×10~6S/m.(3)The parameters of AgNO3 concentration,deposition reaction time,SWNT concentration and hot-pressing pressure were optimized.The results showed that the properties of the composite fibers after hot pressing treatment were better when the concentration of SWNT was 6mg/m L,the concentration of AgNO3 was 0.6mol/L,the deposition reaction time was 40 min,and the pressure was 10 MPa.In this case,the electrical conductivity of the composite fibers could reach 1.9×10~7 S/m,and the tensile strength could reach 80.6 MPa.(4)The application demonstration and environmental test of the textile conductive circuit constructed by composite fiber were carried out.The results showed that the conductive circuit constructed by composite fiber had good mechanical stability,cleaning resistance,environmental stability and timeliness.更多还原