碳纳米管增强天然橡胶复合材料的制备与性能研究

碳纳米管以其特殊的结构与优异的性能成为橡胶的理想填料。本文分别采用四种不同牌号(分别为Flotube7000 9000 9011 9400)的碳纳米管为实验原料,制备了碳纳米管/天然橡胶复合材料,并对其性能进行了研究探讨。结果发现,碳纳米管的加入能显著提高复合材料的力学性能和热导率,具有一维取向排列且长径比较大的Flotube7000(以下简称7000)对力学性能的提高程度最大,Flotube7000以及经过酸处理的表面具有-OH、–COOH官能团的Flotube9011(以下简称9011)对导热性能提高程度最为明显。     

碳纳米管／炭黑／天然橡胶复合材料的性能研究

研究碳纳米管/炭黑/天然橡胶复合材料的性能。结果表明:碳纳米管的加入能明显提高复合材料的定伸应力,具有一维取向排列且长径比较大的碳纳米管Flotube 7000对物理性能的提高作用明显;碳纳米管与炭黑并用对提高复合材料的导热性能具有一定的负协同效应。     

碳纳米管／天然橡胶复合材料的性能研究

研究4种不同牌号的碳纳米管(Flotube 7000,9000,9011和9400)对碳纳米管/天然橡胶复合材料性能的影响。结果表明,碳纳米管的加入能显著提高复合材料的物理性能和热导率,具有一维取向排列且长径比较大的Flotube 7000对物理性能的提高程度最大,Flotube 7000和经酸处理表面具有OH和COOH官能团的Flotube9011对导热性能提高程度最为明显。     

碳纳米管/纳米氧化铝/天然橡胶复合材料的性能研究

以偶联剂Si69原位改性法制备碳纳米管/纳米氧化铝/天然橡胶(NR)复合材料,对其性能进行探讨。结果表明:复合材料的动态力学性能优异,动态压缩生热较低;碳纳米管与纳米氧化铝并用对提高复合材料导热性能具有协同效应,复合材料的导热性能良好。碳纳米管和纳米氧化铝并用可以解决内部温升造成复合材料寿命缩短的问题。     

N234/N660炭黑并用对炭黑在SBR1712橡胶中分散及物理性能影响

通过不同比例的N234/N660炭黑在SBR1712橡胶中的分散状态及物理性能分析,发现N234/N660以不同比例并用时分散度均较其加权平均值明显提高,扫描电镜观察胶料的脆断面发现炭黑结团数目降低,说明N234/N660炭黑的并用能促进炭黑在胶料中的分散。同时炭黑并用混炼胶的各项物理性能高于其加权平均值,说明炭黑分散度的提高对于胶料的各项物理性能的提高有明显效果。不同比例的N234/N660炭黑并用时均产生了协同效应。     

华光炭黑填充丁苯橡胶纳米复合材料的结构与性能

研究华光炭黑用量对丁苯橡胶(SBR)复合材料性能的影响,并与炭黑N330进行对比。结果表明:与炭黑N330相比,华光炭黑具有中空结构、较大的比表面积和较高的结构性;相同用量华光炭黑填充SBR胶料的门尼粘度和拉伸强度较大,导电性能和导热性能较好。随着炭黑用量的增大,两种复合材料的物理性能、导电性能和导热性能均提高。当华光炭黑用量为15份时,华光炭黑/SBR复合材料已成为导电材料。     

功能化碳纳米管/炭黑复合橡胶性能研究

表面活性剂十二烷基苯磺酸钠对碳纳米管进行非共价键改性包覆,研究功能化碳纳米管与炭黑复合材料性能。结果表明,十二烷基苯磺酸钠与碳纳米管的石墨表面形成π-π堆叠,可有效阻止碳纳米管间的团聚。功能化碳纳米管/炭黑复合材料硫化时间缩短,加工性能得到改善,断裂伸长率提高66.1%,导热率提高8.4%。Payne效应和TEM表明,十二烷基苯磺酸钠包覆碳纳米管可有效改善碳纳米管在橡胶基体中分散,也改善了炭黑在复合材料中的分散。混合填料在橡胶基体均匀分散,加强了填料与基体的界面作用,建立良好的三维空间网络结构,使复合材料性能得到改善。     

炭黑N660/裂解炭黑并用在轮胎气密层胶中的应用研究

研究炭黑N660/裂解炭黑并用对溴化丁基橡胶(BIIR)气密层胶性能的影响。结果表明:裂解炭黑粒径大于炭黑N660;随着裂解炭黑用量的增大,胶料的门尼粘度提高,t10和t90总体延长,加工安全性能较好,硫化速度较慢;与纯炭黑N660胶料相比,添加裂解炭黑的胶料物理性能总体降低,炭黑N660/裂解炭黑并用比为40/20的胶料综合物理性能较好,成本降低;炭黑N660/裂解炭黑并用胶料的耐热氧老化性能和气密性较好。     

少量碳纳米管非等量替代炭黑对丁苯橡胶抗疲劳破坏性能的影响

对于炭黑/丁苯橡胶复合材料,分别用1、2和3份(质量,下同)碳纳米管替代4、8和12份炭黑,研究了复合材料在宽应变范围(30%~100%)的抗疲劳破坏性能。结果表明,在30%~70%应变下,与纯炭黑填充的胶料相比,加入碳纳米管疲劳寿命提高,裂纹增长速率降低;在70%~100%应变下,胶料的疲劳寿命降低,裂纹增长速率提高。原因是碳纳米管的加入增大了滞后损失,在小应变下滞后生热可分担部分外界能量,而在大应变下滞后生热增大,使降解加速所致。撕裂能与裂纹增长速率的关系也证明了这一点。此外还证明了采用1份碳纳米管与4份炭黑N 234对丁苯橡胶抗疲劳破坏性能的贡献基本相同。     

DMA研究炭黑/天然橡胶复合材料

选用炭黑N330、N550、N660和白炭黑,利用溶液法/混炼法结合制备炭黑/天然橡胶复合材料,通过控制单因子变量法,利用动态热机械分析(DMA)研究了炭黑种类、温度因素对复合材料力学性能的影响,并与传统混炼法进行了对比。结果表明,溶液法/混炼法结合所得复合材料的力学性能较好;炭黑分散越均匀,炭黑粒径越小,复合材料的储能模量和损耗模量越大;复合材料力学性能稳定性取决于炭黑/天然橡胶的界面结合方式。     

Melt mixing of carbon fibers and carbon nanotubes incorporated polyurethanes

Polyurethane composites filled with carbon fibers (CF) and carbon nanotubes (CNT) were prepared by mixing and injection molding, and its mechanical as well as their thermal properties were investigated. Dynamic mechanical analysis (DMA), thermogravimetry analysis (TGA), and thermal conductivity tests were done, and the properties were evaluated as a function of the filler concentration. The storage modulus of the composites increased with fillers concentration, which also mean the increase of the stiffness, suggest a good adhesion between the polyurethane matrix and the fillers. Addition of more CF and CNT to the composites broadened and lowered the peak of tan δ specifies that the polyurethane composite became more elastic because there is a good adhesion between the fillers and the matrix. The addition of carbon fillers improves the thermal stability of the polyurethane. The inclusions of CNT show a better thermal stability when compared with CF. The addition of carbon fillers also increased the thermal conductivity of the polyurethane composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

CO与CO2甲烷化反应研究进展

介绍了甲烷化反应的催化剂,尤其是Ni基催化剂的研究进展,综述了助剂、载体以及制备方法对甲烷化催化剂催化性能的影响,不同催化剂上CO和CO2甲烷化反应过程的机理。     

Borate treatment of carbon fibers and carbon/carbon composites for improved oxidation resistance

Carbon fibers and carbon/carbon composites have been treated with borate additives and then cured at 500–600°C to produce a continuous film of boron oxide on all exposed surfaces.This treatment has been found to be highly effective in retarding oxidation of the carbonaceous substrate for extended periods in flowing air at temperatures up to 1000°C. At higher temperatures, and in the presence of water vapor, borate species were appreciably volatile and the oxidation protection provided by the coatings was less effective.     

Friction behaviors of carbon/carbon composites with different pyrolytic carbon textures

Friction and wear properties of carbon/carbon (C/C) composites with a smooth laminar (SL), a medium textured rough laminar (RL) and a high textured RL pyrolytic carbon texture were investigated with a home-made laboratory scale dynamometer to simulate airplane normal landing (NL), over landing (OL) and rejected take-off (RTO) conditions. The morphology of worn surfaces at different braking levels was observed with scanning electron microscopy. The results show that C/C composites with RL have nearly constant friction coefficients, stable friction curves and proper wear loss at different braking levels, while friction coefficients of C/C composites with SL pyrolytic carbon decrease intensely and their oxidation losses increase greatly under OL and RTO conditions. Therefore, C/C composites with a high and medium textured RL pyrolytic carbon may satisfy the requirements of aircraft brakes. The good friction and wear properties of C/C composites with RL are due to the properties of RL, which leads to a uniform friction film forming on the friction surface.     

Material advancements in supercapacitors: From activated carbon to carbon nanotube and graphene

The electrochemical capacitor (EC), also known as supercapacitor, is an energy storage device possessing a near infinite life‐cycle and high power density recognised to store energy in the double‐layer or through pseudocapacitance as a result of an applied potential. Fundamental principles of charge storage in relation to the important physical and chemical characteristics of electrode materials are addressed in the following review, with carbon‐made electrodes, specifically activated carbon, carbon fibres and aerogels, carbon nanotubes and graphene emphasised in regards to their enhancement of the characteristic energy and power densities of ECs. Pseudocapacitive materials, notably transition metal oxides and nitrides, and conducting polymers are remarked by the potential to further improve EC performance through synergistic effects and asymmetric design. Research towards gaining a better understanding of charge storage in sub‐micropores, material design and improving the performance of alternative electrolytes are expected to greatly enhance the capabilities of these devices in the near future.     

有序介孔碳和活性炭对阿莫西林的吸附研究

阿莫西林是废水中一类典型的药品与个人护理品类新型有机污染物,会对周围环境和人体健康造成潜在威胁。以蔗糖为碳源、以SBA-15为模板制备有序介孔碳（OMC）。采用动态吸附法研究其对阿莫西林的吸附行为,并与常规吸附材料商用活性炭（GAC）作对比。探讨了废水中阿莫西林的初始浓度、温度及流速对动态吸附的影响。结果表明：在同等条件下,OMC的吸附能力远强于GAC,以OMC为吸附剂可有效去除废水中的阿莫西林类新型有机污染物。     

Frictional properties of diamond-like carbon, glassy carbon and nitrides with femtosecond-laser-induced nanostructure

This paper reports macro and micro frictional properties of DLC, TiN, CrN films and GC substrate of which surfaces are nanostructured with femtosecond (fs) laser pulses. The friction coefficient μ of the nanostructured surface was measured at a usual load with a ball-on-disk friction test machine. The results have shown that carbon materials of DLC and GC provide lower values of μ than TiN and CrN, and μ of DLC and TiN measured with a hardened steel ball decreases with an increase of the laser pulse energy. On the other hand, μ of nanostructured surfaces of thin films monotonously increases with an increase in laser pulse energy, which was measured with a micro-scratch test at an ultralight load of 1.5 mN utilizing a diamond tip. The friction coefficient of the GC substrate irradiated at a low fluence around the ablation threshold has shown a lower value than that of the non-irradiated surface.     

氧化石墨烯的制备及其掺杂的炭/炭复合材料导热性能研究

设定两种不同配比强酸氧化剂,以鳞片石墨为原料,采用Hummers法,制备了氧化石墨烯,再经过高温炭化得到热处理氧化石墨烯。并分别以中间相沥青为基体炭前驱体,炭纤维为增强相,氧化石墨烯及其热处理物为热疏导功能体,制备出掺杂氧化石墨烯的炭/炭复合材料。TEM、SEM等表征表明,选用强酸氧化剂组合配比用量较少的制备出的氧化石墨烯,其形貌整体上要优于用量较多的,具有独特的褶皱结构;相比于氧化石墨烯,掺杂其热处理物的复合材料界面覆盖均匀平滑且结合更优良,且其导热系数可达到60 W.m-1.K-1,是无掺杂的纯复合材料两倍多,导热系数得到了较大幅度提高。