碳纳米管导电纸的制备及改性研究

以纸纤维作为载体,碳纳米管(CNTs)为导电剂,采用普通造纸的工艺制成碳纳米管导电纸。通过对碳纳米管的石墨化处理改性导电纸性能,采用X射线衍射、热重分析、扫描电子显微镜、四探针电阻仪、矢量网络分析仪等对其表征。研究表明,当纸纤维和碳纳米管加载比为1∶1时,碳纳米管经石墨化改性后,导电纸电导率和导热系数大幅增大,在175~2 700 MHz频段,电磁屏蔽效能提高到-28~-35dB,对比未石墨化碳纳米管导电纸屏蔽效能平均提高10dB。     

纳米管协同碳纳米管导电纸对石墨负极性能的影响

以碳纳米管(Multi-walled carbon nanotubes)为导电剂,协同以碳纳米管和纸纤维复合成的CNTs导电纸为集流体,对石墨负极进行电化学改性。石墨化处理碳纳米管作为负极的添加相,采用XRD、SEM和TGA对其分析。结果表明,对比单纯的石墨/铜箔负极,掺杂0.8%(质量分数)石墨化碳纳米管的石墨/铜箔负极,电池比容量由304mAh/g变为308mAh/g,相差不大,但循环效率由86%升至92%;使用CNTs导电纸做集流体时,掺杂0.8%(质量分数)石墨化碳纳米管的石墨/CNTs导电纸负极,比容量由308mAh/g升至401mAh/g,提高30%,循环效率由92%升至95%,提高3%。说明碳纳米管协同CNTs导电纸对石墨负极具有积极的改性意义。     

碳纳米管导电纸集流体对三元锂离子电池的影响

以碳纳米管导体、纤维素纤维为基体制备碳纳米管导电纸。以此碳纳米管纸为集流体替代铝箔作为集流体组装纽扣电池。三元材料(NMC)为正极活性材料,制成浆料涂敷在碳纳米管纸表面制备成正极。利用Raman光谱、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等进行结构和性能表征。通过恒流充放电检测电化学性能。结果表明:碳纳米管导电纸代替铝箔作集流体,具有更好的电化学性能。在0.1C倍率时,三元/导电纸电极首次放电容量达到184mAh/g,三元/铝箔电极为178mAh/g,相比后者,前者提高了3%,在28次循环后,容量保持率在94%以上。     

碳纳米管纸/聚合物复合材料制备及其性能研究进展

碳纳米管纸(又称巴基纸)/聚合物复合材料是纸状的碳纳米管薄层和聚合物复合制成的新型高性能复合材料。巴基纸/聚合物复合材料的制备方法主要有真空过滤热压法、原位电化学法和等离子体法。此种新型碳纳米管复合材料具有优异的电磁屏蔽、力学和电学性能。综述了巴基纸/聚合物复合材料的制备方法、性能及其应用前景。     

水性导电涂料导电性能及屏蔽效能研究

研制了以片状镀银铜粉为导电填料,水性聚氨酯乳液和水性丙烯酸乳液为成膜树脂的水性导电涂料.分析了成膜树脂、填料含量、溶剂种类、涂层厚度对涂膜导电性能的影响,并通过涂层的微观结构和导电机理,探讨了造成这些影响的原因.测试结果表明该涂料有较好的电磁屏蔽效能.     

丙烯酸酯/碳纳米管导电涂料的制备及其性能研究

将碳纳米管经过超声处理和表面包覆改性处理后,填充到丙烯酸酯中,制得一系列丙烯酸酯/碳纳米管导电涂料,考察了涂料相应的电性能、硬度、附着力、柔韧性等。结果表明,所制备的丙烯酸酯/碳纳米管涂料电阻达到了1×103Ω左右,涂料的附着力、硬度、冲击力等性能良好。     

碳纳米管纸/纳米硅复合电极的锂离子电池性能

采用纳米硅和多壁碳纳米管(MWCNTs)复合材料作为活性材料,以纸纤维为基体,MWCNTs为导电剂制得的MWCNTs导电纸代替铜箔集流体应用于硅基锂离子电池。采用扫描电子显微镜、透射电子显微镜、恒流放电测试、电化学阻抗对复合材料的形貌和电化学性能进行分析。结果表明,采用MWCNTs导电纸-纳米硅复合的锂离子电池在80mA/g的电流密度下,循环50次后比容量达到约1000mAh/g,在2000mA/g大电流密度下仍保持好的循环稳定性。     

碳纳米管／PMMA／PVAc复合膜的制备及其导电性能研究

用竖式炉流动法，以二茂铁为催化剂，硫为助催化剂，苯为碳源制备碳纳米管（CNT），反应温度为1100-1200℃，碳纳米管的外径为20-40nm，内径10-30nm，长度5-20μm，并在2800℃对碳纳米管进行石墨化处理。用超声分散和溶液浇铸工艺制备碳纳米管，聚甲基丙烯酸甲酯（PMMA）／聚醋酸乙烯酯（PVAc）复合膜和石墨化碳纳米管／PMMA／PVAc复合膜，石墨化碳纳米管复合膜的导电性能明显优于碳纳米管复合膜，石墨化碳纳米管／PMMA／PVAc复合膜和碳纳米管／PMMA／PVAc复合膜的渗流阈值分别为2．5％和5％（质量分数），碳纳米管／PMMA／PVAc复合膜是很好的气敏候选材料。     

改性导电胶的研究进展

随着电子工业的快速发展,电子产品越来越趋向于微型化、环保化和集成化.传统的电子封装材料大多是含铅焊料,具有粘度高、毒性大和实施温度高等缺点,越来越不能满足这样的趋势需求.导电胶具有粘度低、焊接精细结构,环保、成型温度低和适用范围广等优点,可以作为一种新型的绿色微电子封装互连材料取代含铅焊料.然而相对于含铅焊料,导电胶的电阻率仍然较高,接触电阻稳定性较低,抗冲击性能较差等,限制了导电胶的大规模应用.因此,科研人员和工程师一直在不断努力开发出很多方法,来提高导电胶的综合性能.针对目前的导电胶现状,详细地探讨了近几年通过对导电填抖的表面进行改性来提高导电胶的综合性能的方法.     

Strong and Conductive Dry Carbon Nanotube Films by Microcombing

In order to maximize the carbon nanotube (CNT) buckypaper properties, it is critical to improve their alignment and reduce their waviness. In this paper, a novel approach, microcombing, is reported to fabricate aligned CNT films with a uniform structure. High level of nanotube alignment and straightness was achieved using sharp surgical blades with microsized features at the blade edges to comb single layer of CNT sheet. These microcombs also reduced structural defects within the film and enhanced the nanotube packing density. Following the microcombing approach, the as‐produced CNT films demonstrated a tensile strength of up to 3.2 GPa, Young's modulus of up to 172 GPa, and electrical conductivity of up to 1.8 × 10⁵ S m^?1, which are much superior to previously reported CNT films or buckypapers. More importantly, this novel technique requires less rigorous process control and can construct CNT films with reproducible properties.     

碳纳米管改性聚丙烯复合材料的研究进展

综述了碳纳米管对聚丙烯力学性能改性、电学性能改性、结晶行为改性、阻燃和热稳定性能改性等方面的研究现状,包括单壁碳纳米管和多壁碳纳米管对聚丙烯改性的影响,展望了碳纳米管改性聚丙烯复合材料的发展前景。     

氧等离子体对碳纳米管改性的分子模拟研究

采用密度泛函理论研究了氧等离子体改性前后的(8,0)碳纳米管的性能,比较了改性前后结合能、能带结构及态密度之间的差异,结果表明改性后碳管的结合能变小,其表面的分散性提高,从而可以稳定存在.另外,尽管碳管的能隙Eg非常小,但其价带顶和导带底均未穿过费米能级,验证了(8,0)碳纳米管是半导体管的理论.改性后碳纳米管的几何结构受到羟基和羧基的影响很大,横截面C-C间距增大,比表面积增加;同时,羟基和羧基使得费米能Ef以及费米能级上的态密度明显增大,而且羧基的作用更显著,这表明氧等离子体增强了碳纳米管的化学活性,是一种有效的改性方法.     

Stretchable Transparent Conductive Films from Long Carbon Nanotube Metals

Flexible transparent conductors are an enabling component for large‐area flexible displays, wearable electronics, and implantable medical sensors that can wrap around and move with the body. However, conventional conductive materials decay quickly under tensile strain, posing a significant hurdle for functional flexible devices. Here, we show that high electrical conductivity, mechanical stretchability, and optical transparency can be simultaneously attained by compositing long metallic double‐walled carbon nanotubes with a polydimethylsiloxane substrate. When stretched to 100% tensile strain, thin films incorporating these long nanotubes (≈3.2 µm on average) achieve a record high conductivity of 3316 S cm^?1 at 100% tensile strain and 85% optical transmittance, which is 194 times higher than that of short nanotube controls (≈0.8 µm on average). Moreover, the high conductivity can withstand more than 1000 repeated stretch‐release cycles (switching between 100% and 0% strain) with a retention approaching 96%, whereas the short nanotube controls exhibit only 10%. Mechanistic studies reveal that long tubes can bridge the microscale gaps generated during stretching, thereby maintaining high electrical conductivity. When mounted on human joints, this elastic transparent conductor can accommodate large motions to provide stable, high current output. These results point to transparent conductors capable of attaining high electrical conductivity and optical transmittance under mechanical strain to allow large shape changes that may take place in the operation and use of flexible electronics.