8-羟基喹啉插层蒙脱土/丙烯酸酯复合荧光材料的制备

为了制备具有良好加工性能和高荧光强度的8-羟基喹啉(8-OQ)类有机光致发光材料,以铝基蒙脱土(MMT)中的Al(Ⅲ)为配位中心、8-OQ为配体合成了高荧光性8-OQ插层MMT(FS-MMT),并将其与环氧丙烯酸酯(EA)复合,采用UV固化法制备了高荧光性FS-MMT/EA涂层。采用红外、X射线衍射、紫外-可见光吸收光谱及分子荧光谱仪表征了FSMMT,并研究了FS-MMT/EA涂层的吸收及荧光光谱行为。结果表明,成功制备了FS-MMT,其紫外-可见光吸收光谱分析表明8-OQ与MMT上的Al(Ⅲ)发生配位作用;而荧光强度较Alq3显著增强。而FS-MMT/EA涂层的荧光发射峰出现在490 nm附近,较FS-MMT的发生了蓝移;同时荧光强度随FS-MMT含量增加而增强,且较FS-MMT的有明显升高。     

超支化含P,N活性预聚物/环氧丙烯酸酯涂层的阻燃及热稳定性

为改善环氧丙烯酸酯(EA)涂层的阻燃及热稳定性,通过环氧树脂YPE-128与磷酸反应合成了超支化含磷环氧树脂(HPEP),再将HPEP与羟乙基丙烯酸酯-甲苯二异氰酸酯的半加成物反应制备出超支化活性阻燃预聚物HPCA,并将其与环氧丙烯酸酯体系复配,经UV固化制备了含P,N阻燃元素的EA涂层。利用红外光谱、紫外-可见分光光度计、热重、氧指数仪、锥形量热计和垂直燃烧仪表征了产品结构与涂层的透过率、阻燃性及热稳定性。结果表明,添加HPCA的涂层具有较高的可见光透射率,且能促进涂层低温降解形成膨胀阻燃涂层,能显著改善涂层的高温阻燃性及热稳定性。且当HPCA质量分数为50%时,涂层阻燃效果最佳,600℃成炭率、极限氧指数、垂直燃烧级别及峰热释放速率分别为21.9%,39,V-0和248 kW/m~2。     

等离子喷涂CNTs/Al2O3复合涂层力学性能研究

通过等离子喷涂工艺制备了不同碳纳米管含量的CNTs/Al2O3复合涂层,系统研究了碳纳米管含量对涂层孔隙率、洛氏硬度和断裂韧性的影响规律。实验结果表明:采用喷雾干燥工艺制备的CNTs/Al2O3颗粒为球形,CNTs均匀分布在团聚颗粒的表面;部分CNTs经等离子喷涂后保留在沉积涂层内部并且与Al2O3基体形成冶金结合,起到一定桥接作用。涂层孔隙率和洛氏硬度值均随CNTs含量的增加呈现降低的趋势。随CNTs含量从6%(质量分数)增加到12%(质量分数),CNTs增韧效果的增强和涂层孔隙率的降低导致涂层断裂韧性值从48MPa增加到90MPa。     

微弧等离子喷涂碳纳米管/纳米Al2O3-TiO2复合涂层高温性能研究

采用等离子喷涂技术制备了5wt%CNTs/Al2O3-TiO2复合涂层,借助SEM、热红联仪和RAM反射率测试系统对CNTs/Al2O3-TiO2复合涂层的组织结构、高温氧化性能、电磁特性进行了分析.结果表明:CNTs/Al2O3-TiO2复合涂层的组织结构致密、孔隙率低,CNTs分散均匀,碳纳米管与Al2O3-TiO2陶瓷粘结剂之间具有良好的界面相容性.在20～700℃高温氧化过程中,CNTs起始失重温度为471.29℃,CNTs/Al2O3-TiO2复合涂层的高温氧化性能有一定提高,起始失重温度从471.29℃提高到507.8℃,而碳纳米管的失重率从100%下降到33.68%.CNTs/Al2O3-TiO2复合涂层具有较好的高温吸波性能,25℃时复合涂层的反射率峰值为-7.86dB.随温度的升高,CNTs/Al2O3-TiO2复合涂层的反射率峰值不断减小,谐振频率向低频移动,300℃时复合涂层的反射率峰值为-12.88dB,小于-5dB频带宽为4.48GHz.     

二次掺杂制备聚苯胺/石墨烯/碳纳米管复合材料及其防腐性能EI北大核心CSCD

在高氯酸体系中通过原位聚合将苯胺(ANI)单体分别与还原氧化石墨烯(RGO)、碳纳米管(CNTs)制备了一次掺杂态产物PANI/RGO和PANI/CNTs,产物分别经氨水解掺杂后,在高氯酸体系中经二次掺杂制备得到二次掺杂态聚苯胺/石墨烯/碳纳米管(Redoped PANI/RGO/CNTs)复合材料。通过扫描电镜、透射电镜、傅里叶变换红外光谱和紫外光谱对其不同产物形貌和结构进行表征,通过电化学工作站测试了不同产物在3.5%NaCl溶液的防腐蚀性能。结果表明,在RGO与ANI质量比为1:20、CNTs与ANI质量比为1:20时,二次掺杂态产物中聚苯胺纳米纤维可分别在RGO和CNTs上均匀生长并形成网状结构,纤维长度达到850 nm,形貌均一,其防腐蚀性能最优异,缓蚀效率可达81.79%。通过二次掺杂将PANI/RGO和PANI/CNTs复合制备Redoped PANI/RGO/CNTs材料,可有效避免石墨烯和碳纳米管在制备复合材料过程中的团聚,得到结构规整、防腐性能更优异的复合材料。     

高能球磨法制备的CNTs/Al-5%Mg复合材料的力学性能及断裂特性

采用高能球磨法制备了不同质量分数碳纳米管(CNTs)与Al-5%Mg(质量分数)粉末的复合粉末,用热压烧结工艺制备了CNTs/Al-5%Mg复合材料。结果表明:高能球磨法可以将CNTs均匀的分散到基体中,并与其产生良好结合;CNTs具有细化复合粉末晶粒尺寸的作用,当CNTs含量为3%时,复合粉末的平均晶粒尺寸达到最小值为63.6nm,继续增加CNTs的含量,复合粉末平均晶粒尺寸增大;当CNTs含量为2%时,复合材料的抗拉强度和硬度达到最大值,与基体材料相比分别提高了42.39%和36.5%;CNTs/Al-5%Mg复合材料的强化机制为细晶强化和载荷传递。     

航空用磁性胶粘剂的性能研究

首先对原始碳纳米管(CNTs)进行了纯化处理,再采用化学镀的方法制备了镀镍碳纳米管(Ni/CNTs),并采用溶液共混法制备镀镍碳纳米管/聚丙烯酸酯磁性压敏胶(Ni/CNTs/PSA)。扫描电镜(SEM)及X射线能谱仪(EDS)显示CNTs表面镀上了一层均匀紧凑的金属镍,镍层厚度约为50nm。SEM显示Ni/CNTs均匀地分散在聚丙烯酸酯(PSA)中。Ni/CNTs/PSA的饱和磁化强度(Ms)随着Ni/CNTs含量的增加而增大,Ni/CNTs/PSA的180°剥离强度随着Ni/CNTs含量的增加逐渐下降,剪切强度先上升后下降。当Ni/CNTs的含量为3.0%(体积分数)时,磁性压敏胶综合性能最佳。     

耐温布拉格光栅传感器用纳米蒙脱土改性环氧丙烯酸酯涂层的制备

对纳米蒙脱土(OMMT)进行改性, 用改性后的蒙脱土对环氧丙烯酸酯(EA)涂层进行改性, 并对改性后的OMMT/EA涂层进行了力学性能和热性能测试。研究表明, 加入质量分数2%改性蒙脱土的OMMT/EA涂层性能最好。OMMT的加入可提高涂层的拉伸性能、附着力和硬度, 并有效提高EA涂层的玻璃化温度, 降低其线性热膨胀系数。电镜和XRD分析表明, OMMT在OMMT/EA涂层中以单层片层均匀分布。将涂有该涂层的光纤布拉格光栅(FBG)传感器埋入复合材料中, 经一定温度与压力成型后, 与涂有未改性EA涂层的FBG传感器采集到的信号进行对比, 发现改性后涂层可明显降低FBG传感器信号滞后现象。     

碳纳米管/纤维素纤维复合纸及其电磁屏蔽性能研究

研究了以碳纳米管(CNTs)作为导电剂纤维素纤维为基体的复合纸的制备工艺和电磁屏蔽性能。通过使用球磨、超声、剪切和磁力搅拌等多种分散工艺制得CNTs/纤维素纤维复合纸,研究了不同分散工艺对复合纸性能的影响,并确定最佳制备工艺。采用扫描电镜(SEM)、透射电镜(TEM)和X-射线衍射(XRD)对CNTs检测检测。采用四探针电阻仪、矢量网络分析仪对CNTs/纤维素纤维复合纸进行性能检测。研究结果表明,球磨与剪切复合工艺制得的CNTs/纤维素纤维复合纸电导率达到47.35S/m,电磁屏蔽效能最高,为18~22.5dB,具有较好的性能。     

化学沉积法制备Ni—Cu—P／CNTs复合涂层及其表征

利用化学沉积法在45^#钢基体上成功制备出Ni—Cu-P／CNTs复合涂层，为了降低碳纳米管的长径比以及提高在镀液中的分散性，对其硝酸纯化、15min球磨处理，研究了沉积液组成对Ni-Cu-P／CNTs复合涂层沉积速率的影响，通过TEM、SEM和EDS表征了复合涂层的表面形貌和微观结构。结果表明：碳纳米管的分散性良好，在复合涂层中分布均匀，复合涂层在400℃热处理后结构更加致密，EDS表明复合涂层中碳纳米管的质量分数达到3．68％。     

Large-area, high-speed patterning of carbon nanotubes using material-assisted excimer laser photoablation

Large-area patterning of carbon nanotubes (CNTs) using a nonlithographic process is demonstrated. Projection imaging with deep ultraviolet radiation from 248 nm KrF excimer laser and material-assisted photoablation were used to pattern the CNTs. A matrix of CNTs dissolved in a DMF solution was deposited on a silicon wafer by spin coating, followed by coating of photodefinable polyimide on the CNTs. The CNTs and the polyimide layer were simultaneously patterned by the excimer laser projection photoablation process. Even though CNTs cannot be directly photoablated by low-fluence excimer laser radiation, simultaneous patterning of the illuminated CNT-polyimide combination region occurred due to the physical force of dissociated fragments of polyimide layer. We have demonstrated clean, large-area patterning of CNTs on 100 mm diameter Si wafers. Additionally, this patterning process is economical and provides higher throughput compared with conventional methods.     

超双疏耐磨PPS基涂层的制备与性能

以NH_4HCO_3为造孔剂,碳纳米管(CNTs)为纳米级纤维填料,采用简单的喷涂工艺制备出超双疏耐磨聚苯硫醚(PPS)基涂层。采用扫描电镜(SEM)、接触角测量仪分析涂层的表面形貌和疏水、疏油性能。采用定载砂纸打磨法测试双疏涂层的耐磨损性能。结果表明:造孔后的涂层表面粗糙,表面的多孔结构和CNTs构成了特殊的微纳二元复合网络结构。当NH_4HCO_3的含量为5%(质量分数)时,涂层实现超疏水和超疏油,对水、甘油和乙二醇的接触角分别为162°,158°和152°。用砂纸反复打磨10000次后,涂层表面轻微磨损,仍保持了高疏水效果,具有良好的耐磨性能。     

非共价法硫化锌修饰碳纳米管复合材料的制备

采用非共价法，利用两种不同的工艺成功制备了ZnS／CNTs复合材料。研究表明，沉淀法得到的复合材料中ZnS是立方相，而回流法得到的ZnS是六方相：碳纳米管经过SDS改性后，硫化锌粒子都成功地对碳纳米管进行了修饰，但回流法的修饰效果要明显好于沉淀法。用两种工艺制备的样品均可被紫外光激发产生荧光，但六方ZnS产生的荧光明显强于立方ZnS，并且六方ZnS产生的余辉时间较长，而立方ZnS产生的余辉较短。     

CNTs增强Cr基复合电刷镀层的性能

以45号钢为基体,采用电刷镀制备了Cr-CNTs复合镀层。通过X射线衍射仪(XRD)、扫描电镜(SEM)、扫描电子显微镜附带能谱仪(EDS)等技术对镀层的晶粒尺寸,截面与表面形貌及CNTs在镀层表面的分布进行了表征。此外,利用显微硬度计、电化学工作站、磨损试验机等仪器对镀层的硬度、抗腐蚀性、耐磨性等进行了测试。研究结果表明:Cr-CNTs复合镀层组织致密无明显缺陷,CNTs弥散分布于镀层中,在胞状组织的交界处出现了富集;适量CNTs的加入在一定程度上细化了镀层的晶粒;在CNTs弥散强化和细晶强化等作用下,复合镀层的硬度提高了23.8%,腐蚀速率降低了49.2%,而且耐磨性能也得到了显著的改善。     

A carbon nanotube–enhanced SiC coating for the oxidation protection of C/C composite materials

A carbon nanotube–enhanced SiC (CNT–SiC) coating was deposited on C/C composites to improve the oxidation resistance of C/C. The CNT–SiC coating was prepared by direct growth of CNTs on C/C surface at 700 °C followed by deposition of SiC using chemical vapor deposition at 1150 °C for 1 h. SiC was deposited on the CNTs as well as the interface between CNTs and C/C, making CNTs strongly rooted on C/C surface. The final CNT–SiC coating consisted of two layers: the CNT–SiC layer and SiC layer. In comparison to the SiC coating, the CNT–SiC coating showed fewer cracks and a better oxidation resistance because the CNTs reduce the stress in the coating caused by the mismatch of the coefficient of thermal expansion between C/C and SiC.     

Carbon fiber/epoxy composite property enhancement through incorporation of carbon nanotubes at the fiber–matrix interphase – Part I: The development of carbon nanotube coated carbon fibers and the evaluation of their adhesion

A new method to realize the uniform coating of carbon nanotubes (CNTs) to carbon fibers (CFs) has been developed, which enables the scalable fabrication of CNT containing CF/epoxy composites. In this method, CNTs are treated by cationic polymers, then, the CNTs are coated to CFs by immersion into a CNT/water suspension. Good dispersion is achieved by repulsive force between positively charged CNTs and uniform coating of the CNTs is achieved by attractive forces between positively charged CNTs and negatively charged CFs. It is found that the use of specific cationic polymers including polyethyleneimine (PEI) results in stable CNT/water suspensions, and uniform coating of the CNTs. Single fiber fragmentation tests of the CF/epoxy composites were conducted to evaluate the strength of interface and interphase under shear loading. The results show that the combination of epoxy resin sizing and PEI treated CNT coating to CFs results in high interfacial shear strength.     

Effect of a multiscale reinforcement by carbon fiber surface treatment with graphene oxide/carbon nanotubes on the mechanical properties of reinforced carbon/carbon composites

An effective carbon fiber/graphene oxide/carbon nanotubes (CF-GO-CNTs) multiscale reinforcement was prepared by co-grafting carbon nanotubes (CNTs) and graphene oxide (GO) onto the carbon fiber surface. The effects of surface modification on the properties of carbon fiber (CF) and the resulting composites was investigated systematically. The GO and CNTs were chemically grafted on the carbon fiber surface as a uniform coating, which could significantly increase the polar functional groups and surface energy of carbon fiber. In addition, the GO and CNTs co-grafted on the carbon fiber surface could improve interlaminar shear strength of the resulting composites by 48.12% and the interfacial shear strength of the resulting composites by 83.39%. The presence of GO and CNTs could significantly enhance both the area and wettability of fiber surface, leading to great increase in the mechanical properties of GO/CNTs/carbon fiber reinforced composites.     

Enhancement of field emission property from hills-like carbon nanotubes film

Improved field emission property of carbon nanotubes (CNTs) is achieved by using NiTi alloy film as catalyst under optimized condition. The NiTi alloy films are prepared by magnetron co-sputtering process and the CNTs films are synthesized by thermal chemical vapor deposition. With the increase of the Ni/Ti ratio from 19 at.% to 95 at.%, the CNTs density increases from discrete cluster to dense network, and the optimized field emission property of CNTs film is found at the medium density. However, the field emission property is significantly enhanced when the Ni/Ti ratio is about 76 at.%, and it is supposed to attribute to the combined effect of the hills-like surface enhancement and the intrinsic emission properties of CNTs.     

Incorporation of carbon nanotubes into micro-coatings film formed on aluminum alloy via plasma electrolytic oxidation

The influence of the incorporation of carbon nanotubes (CNTs) on the coating structure of aluminum alloy processed by plasma electrolytic oxidation (PEO) has been studied as a function of the current density. A series of PEO coatings was applied in a silicate-electrolyte containing CNTs at three current densities, such as 50, 100, and 150 mA/cm². As the current density increased, the responding voltage also increased due to a gradual increment in the amount of CNTs incorporated uniformly into the coating film. In addition, a number of CNTs were observed mainly near micro-pores formed in the coating film by plasma explosive arcs, resulting in a fairly uniform coating structure with a low density of micro-pores. This phenomenon was discussed based on the electrophoretic activity of CNTs.