直线型和弯曲型纳米碳管特性对纳米复合材料有效力学性能的影响

在ANSYS平台构建直线型和弯曲型的实心和空心纳米碳管增强陶瓷基复合材料的三维特征体积单元模型.利用双尺度渐近均质化理论计算复合材料的有效力学性能,分析纳米碳管的几何形状和力学特性对复合材料有效刚度的影响.分析结果表明,随着长度和直径的变化,实心纳米碳管与空心纳米碳管增强复合材料的有效力学性能效果差异较大,两者具有不可替代性.而且纳米碳管的各向异性明显导致有效刚度降低,忽略纳米碳管的各向异性会高估复合材料的有效力学性能.此外,纳米碳管的弯曲程度对横向有效弹性模量和有效剪切模量有较显著的影响.正确构建纳米碳管模型,合理选择纳米碳管的形状和尺寸对准确评估纳米碳管增强复合材料的有效力学性能有重要意义.     

激光熔铸纳米碳管/铝基复合材料的工艺参数

采用激光熔铸工艺制备多壁纳米碳管（MWNTs）增强纯铝复合材料，研究不同铸模条件和激光工艺参数对复合材料熔铸缺陷和组织结构的影响。结果表明：在相同的激光工艺条件下，石墨铸模中激光熔铸的复合材料熔铸缺陷少，组织均匀细小；在相同的激光功率和铸模条件下，扫描速度为60mm/min时，熔铸的复合材料的熔铸缺陷最少，组织最均匀细小。     

纳米SiO2对环氧树脂浇铸体性能的影响

以纳米SiO2作为增强材料，制备纳米复合材料，研究了不同的纳米SiO2含量对纳米复合材料冲击强度，拉伸模量，玻璃化温度的影响，采用正电子湮没技术研究纳米粒子对自由体积参数的影响。结果表明，当纳米粒子SiO2含量为3％时，纳米复合材料的拉伸模量为3．57GPa，冲击强度为15.94kJ/m^2，玻璃化温度为126．65℃，分别比纯基体提高了12．6％，56．3％，40．4％。     

纳米碳管/聚醚酮酮复合材料的研究

采用原位聚合法合成了不同纳米碳管（CNTs）含量的纳米碳管／聚醚酮酮（CNTs／PEKK）复合材料，并利用红外光谱、差示扫描量热分析、热重分析、扫描电镜等对复合材料进行了表征。研究结果表明，在未经有机化处理的情况下，纳米碳管以纳米结构状态分散在基体中，显著地提高了聚醚酮酮的耐热性能，降低了其熔点。     

多壁纳米碳管的压力储氢研究

采用催化热解法制备了多壁纳米碳管，并对其进行酸化、灼烧、掺杂等一系列预处理后，在室温及氢气的压力分别为9，12MPa的条件下研究了多壁纳米碳管的储氢性能。通过对纳米碳管的不同处理可以提高纳米碳管储氢容量，掺杂金属锂后，纳米碳管的储氢量增加最大。     

Co/MgO固体催化剂CVD法合成单壁纳米碳管的研究

分别用浸渍法、离子吸附沉淀法、溶胶一凝胶法制备了四组Co／MgO催化剂．1000C时,这些催化剂均能在CH4气氛下合成单壁纳米碳管,产量受催化剂活性组分尺寸影响明显．经透射电子显微镜(TEM)和热重分析(TGA)结果发现,浸渍法中以乙醇作为溶剂制备的催化剂所制得的产物中含有最多的单壁纳米碳管;离子吸附沉淀法所得的催化剂因沉淀的活性组分颗粒过大而不适合于单壁纳米碳管的生长;溶胶一凝胶法通过优化工艺将有望获得高产率的制备单壁碳管的催化剂．TEM和电子衍射观测同时表明所制得的单壁纳米碳管的直径都分布在1nm左右,且大部分聚集成束．     

纳米ZnO/PP复合材料性能研究

以钛酸酯偶联剂对不同粒径的纳米ZnO粒子进行表面处理 ;采用熔融共混工艺制备了纳米ZnO/PP复合材料 ;并对复合材料力学性能及其结晶性能进行研究。结果表明 :偶联剂改善了复合材料的力学性能 ;平均粒径为 80nm的纳米ZnO质量分数为 4 %时 ,其复合材料的综合性能相对较好 ,复合材料的冲击强度、拉伸强度和弯曲强度均得到不同程度的提高 ;纳米ZnO具有异相成核作用 ,能够起到细化PP球晶的作用。     

纳米SiO2的表面处理及HDPE/SiO2复合材料研究

采用多种方法对纳米SiO2粒子进行表面处理,通过母料法工艺制备了HDPE/纳米SiO2复合材料,研究了纳米SiO2的含量对HDPE复合材料性能的影响.结果表明:经适当处理的纳米SiO2粒子能均匀地分散在HDPE中,能显著改善HDPE复合材料的力学性能;当纳米SiO2的质量分数为6%时,HDPE复合材料的综合力学性能最佳.     

镍基纳米碳管复合镀层的摩擦磨损性能

利用化学镀方法制备镍基纳米碳管复合镀层,用扫描电镜分析了镀层的表面形貌,并用销-盘式磨损试验机研究了复合镀层在干摩擦条件下的摩擦磨损行为.结果表明:纳米碳管均匀地嵌入在镍基体中,镍基纳米碳管复合镀层具有优良的耐磨性能;由于纳米碳管的自润滑作用,复合镀层的摩擦系数随着纳米碳管体积分数的增加而逐渐降低.     

催化分解制备纳米碳管的催化剂研究

对催化解解法制备纳米碳管的催化剂作了初步的探讨和研究,并对纳米碳管生物的影响朵理进行了分析。实验表明：载体的选择、催化剂的制备温度和反应气体的流量对纳米碳管生长有较大的影响,而制备的催化剂粒度越小,越有利于纳米碳管的生长;使用硅胶分散剂的催化剂与直接使用纳米金属颗粒催化剂相比,前者生成的纳 纯度较高,后者生成的是纳米碳管与纳米碳纤维的混合体;一定的后处理工艺可以纯化纳米碳管产物。因此,这是一种快速     

Effect of Co-polyester antistatic agent modified by carbon nanotubes on the properties of polypropylene fibers

Antistatic polymer fibers were investigated by using carbon nanotubes (CNTs) to enhance the antistatic ability of inner antistatic agents based on the mechanism of attracting moisture by polar radical groups. It is indicated that the antistatic ability of the fibers filled with composite antistatic agents that contain CNTs and organic antistatic agents was superior to that of the fibers filled either with pure organic antistatic agents or pure CNTs. The antistatic ability of the composite antistatic agent fabricated by an in situ process was superior to that of the composite antistatic agent fabricated by direct dispersing CNTs in the antistatic agent carrier. Moreover, the heat-treated CNTs could further enhance the antistatic effect compared with the initial CNTs. The antistatic effect is significantly influenced by the content of CNTs in the composite antistatic agent.     

碳纳米管复合镀层的界面结合

在锡铅合金基体上制备了碳纳米管镍基复合镀层,并利用水浴加热熔化基体的方法,成功制备出碳纳米管镍基复合镀层结合界面试样.采用场发射扫描电镜分析了复合镀层的表面和初始界面上的碳纳米管存在形式和分布.结果表明:碳纳米管可以部分直接沉积在初始界面,部分碳纳米管嵌入镍基镀层中.碳纳米管的有效嵌入镍基镀层有利于增强复合镀层的界面结合.     

Properties and Structure of Magnesium Matrix Composite Reinforced with CNTs

By using high pure Magnesium (99.9 wt% ) as matrix and multi-walled bended carbon nanotubes ( CNTs ) as reinforced phase, carbon nanotubes/magnesium matrix composite was prepared to the foundry method under the argon gas protection, and its mechanical properties were tested. The interface structure and component of plating and un-plating carbon nanotubes were analyzed by TEM and EDS , and the action mechanism was discussed. The experiment results show that the CNTs con strengthen mechanical properties of the nano-tube-reinforced Mg matrix composite, the tensile strength and elongation ratio are greatly improved. Furthermore, the plating CNTs are better than un-plating CNTs in strengthening effects. The tensile strength is inereased by 150% and the elongation ratio is increased by 30% than that of matrix when content of CNTs is 0.67 wt%.     

Development of supercapacitors based on carbon nanotubes

Block-type electrodes made of carbon nanotubes were fabricated by different processes. The volumetric specific capacitance based on such electrodes reached 107 F/cm3, which proves carbon nanotubes to be ideal candidate materials for supercapacitors. The composite electrodes consisting of carbon nanotubes and RuO2 ·xH2O were developed by the deposition of RuO2 on the surface of carbon nanotubes. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 600 F/g can be achieved when the weight percent of RuO2· xH2O in the composite electrodes reaches 75% . In addition , supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.     

超声辐照制备聚苯胺/碳纳米管复合微管

利用超声空化产生的强烈粉碎、分散等作用,在实现碳纳米管(CNTs)纳米分散的同时通过化学氧化法聚合单体苯胺,制备了聚苯胺(PANI)包覆CNTs结构的复合微管。用苯胺浸润CNTs解决了CNTs难于分散在HCl溶液中的问题。通过调节单体苯胺和CNTs的用量比调控PANI/CNTs复合微管的管径。XPS测试表明CNTs不影响PANI的掺杂度,但有利于稳定PANI的醌环结构。CNTs的加入提高了PANI的电性能,CNTs含量为12.82％时,PANI/CNTs复合材料比纯PANI的电导率高9.5倍。     

金属Co催化直流碳弧放电产物的研究

在直流碳弧法的阳极棒中掺入金属Co作催化剂生产单壁碳纳米管和碳包Co纳米晶 对产物进行了X射线衍射分析 ,用高分辨电镜观察单壁碳纳米管和碳包Co纳米晶的形貌 ;并比较了碳包Co的含量对Co纳米晶产量和粒径大小的影响 ;研究结果表明阳极棒中Co的加入有利于曲卷状的石墨结构碳纳米管和碳包Co纳米晶的形成 ,而纳米晶粒的粒径大小则随Co含量的增多而增大     

碳纳米管增强铝基复合材料制备及性能研究

采用真空热压烧结法制备碳纳米管与 SiO2多相增强铝基复合材料,测量复合材料的体积密度,根据其理论密度计算其致密度;再对制得的复合材料进行硬度、抗压强度、抗剪强度等力学性能测试,并观察样品的剪切断口微观形貌,研究 CNTs 对复合材料力学性能的影响。低含量的碳纳米管由于其在铝基体中的分散性及弥散度较好,作为第二相增强相,所制备的铝基复合材料的致密度、硬度、抗压强度与剪切强度均优于高含量碳纳米管增强铝基复合材料。 CNTs 的含量、以及其在铝基体中的弥散度是影响铝基复合材料力学性能的关键因素。     

镍基纳米碳管/二氧化钛复合镀层的制备及性能

为了改善金属基材的表面性能,以钛铁矿为原料,利用微波等离子体化学气相沉积法制备了纳米碳管/二氧化钛复合粉体.采用复合电泳电沉积法在不锈钢基体表面制备了镍基纳米碳管/二氧化钛复合镀层;利用扫描电镜、X射线衍射仪、数显维氏硬度计和电化学测试等手段研究了纳米碳管/二氧化钛复合粉体对复合镀层结构和性能的影响.结果表明纳米碳管/二氧化钛复合粉体的加入有效地减小了复合镀层中镍的晶粒尺寸,促进了金属镍沿(111)晶面择优取向生长,改变了镍的电沉积层结构,提高了镀层的硬度,改善了镀层的耐腐蚀性能;在复合粉体的作用下,复合镀层的硬度与纯镍镀层相比提高了110%,腐蚀电位正移了23mV,腐蚀电流密度减少了0.991微安/平方厘米.     

Preparation and properties of multi-wall carbon nanotube/SiC composites by aqueous tape casting

MWCNTS/SiC composites were fabricated by aqueous tape casting. High solid content (50 vol%) SiC slurries with sintering additives and multi-wall carbon nanotubes (MWCNTs) as reinforcements were prepared using Tetramethylammonium hydroxide as the dispersant. The stability of MWCNTs/SiC slur-ries was studied and characterized in terms of zeta potential and rheology measurements. The relative density of the composite was about 98% after hot-pressing at 1850℃ (at 25 MPa in Ar for 30 min). The hardness of the composites decreased with the increase in MWCNTs content. The flexural strength and the fracture toughness were 742.17 MPa and 4.63 MPa·m1/2, respectively when the MWCNTs content was 0.25 wt%. Further increase in MWCNTs content to 0.50 wt% did not lead to the increase in mechanical properties. Most of MWCNTs were found to be located at SiC grain boundaries and the pull out of the MWCNTs was observed.