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聚乙烯/碳黑导电复合材料的导电性能 总被引:3,自引:0,他引:3
提出并验证了聚乙烯/碳黑(PE/CB)导电复合材料的网络导电性能和产生正温度系数(PTC)特性的原因,分析了加工过程、温度和辐射交联等后处理过程对其导电性能的影响. 相似文献
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原位缩聚法制备碳纳米管/尼龙11复合材料 总被引:1,自引:0,他引:1
用原位缩聚法制备了碳纳米管增强的尼龙11复合材料,用X射线衍射仪、红外(FTIR)、扫描电镜(SEM)、热重(TGA)、机械拉伸测试仪等对其结构、形貌、热性能及机械性能进行了表征测试.扫描电镜结果显示碳纳米管均一地分散在尼龙11/碳纳米管复合材料中.复合材料的拉伸模量比纯尼龙11有较大的提高.当复合材料中碳纳米管含量分别为1%,5%,10%时,材料的拉伸模量分别提高了34.5%,92.9%和113,7%.同时,复合材料的储能模量也有提高.热分析结果显示当复合材料中碳纳米管含量为1%时,其失重5%和10%的温度分别由纯尼龙11的404℃、424℃提高到414℃和437℃.示差扫描量热分析(DSC)显示复合材料的结晶温度随碳纳米管的加入而升高,而结晶度则降低. 相似文献
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碳纳米管(CNTs)自从1991年被发现以来,以其特有的力学、电学和化学性能以及独特的准一维管状分子结构和在未来高科技领域中所具有的许多潜在应用价值,迅速成为化学、物理及材料科学领域的研究热点[1]。碳纳米管的C-C共价键链段结构与高分子链段结构相似,能通过配位键作用与高分 相似文献
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聚苯胺/纳米二氧化锰复合材料Ⅰ.原位氧化合成制备 总被引:6,自引:1,他引:6
用固相合成法制备了纳米二氧化锰(nm-MnO2),并通过原位聚合法制备了聚苯胺/纳米二氧化锰复合材料。研究结果表明:在苯胺/nm-MnO2的盐酸反应体系中,nm-MnO2可以使苯胺氧化聚合。在一定的nm-MnO2用量下,聚苯胺的产率随苯胺添加量的增加而下降,nm-MnO2在产物中的含量也随之下降,且含量很低。在苯胺:/nm-MnO2/过硫酸铵的反应体系中,研究了Nm-MnO2通过两种不同的加料方式原位制备PA-NI/nm-MnO2复合材料的合成条件。第一种方式为nm-MnO2和过硫酸铵同时与苯胺混合,一起参与苯胺的氧化聚合。第二种方法是先将过硫酸铵和苯胺混合,3min后再将nm-MnO2加入反应体系中。研究表明:第一种加料方式得到的队NI/nm-MnO2中nm-MnO2的含量很低;第二种加料方式可以得到高nm-MnO2含量(w=0.14-0.73)的产物,其电导率约10^-4S/cm。 相似文献
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利用端羟基超支化聚胺-酯(HBP3-OH)与马来酸酐的酯化反应,合成了含双键的超支化聚胺-酯(HBP3-MA),并用红外光谱和核磁共振光谱对HBP3-MA进行了表征.将HBP3-MA作为改性剂,液体硅橡胶为基体,镀银铜粉为导电填料,制备了改性硅橡胶导电复合材料.HBP3-MA参与到液体硅橡胶的固化,采用示差扫描量热仪(DSC)对复合体系的固化条件进行了研究.采用原位还原法在复合体系中生成纳米银,利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)对银纳米粒子的形貌和复合体系的结构进行了表征,探讨了纳米粒子增强复合物体系导电性的机理,即银纳米粒子具有低温烧结的特性,固化时可在镀银铜粉表面烧结,降低了镀银铜粉之间的接触电阻.最后,对导电复合材料的导电性能和粘结性能进行了研究.研究发现,当醋酸银用量为4.4份时,导电复合材料的体积电阻率和剪切强度均达到最佳值,分别为3.6×10-3Ω·cm和0.32 MPa. 相似文献
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以2,5-二甲基-2,5-双(叔丁基过氧基)己烷(DHBP)在聚丙烯体系中引发形成自由基,以二硫化四甲基秋兰姆(TMTD)调控自由基反应,通过熔融共混一步法制备了共价接枝的聚丙烯/碳纳米管(PP/CNTs)复合材料。 通过拉曼光谱和透射电子显微镜证明发生了共价接枝反应,并研究了PP/CNTs的结晶性能、热性能与力学性能。 结果表明,发生共价接枝的PP/CNTs与未接枝的PP/CNTs及PP相比,其结晶温度分别提高了2.6和12.0 ℃,热分解温度T5%分别提高了6.4和34.8 ℃,其拉伸强度和拉伸模量略有提高,冲击强度分别提高了56.7%和58.1%。 相似文献
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利用聚偏氟乙烯(PVDF)微小结晶的物理交联点作用,制备了形状记忆性能优异的聚偏氟乙烯/丙烯酸酯聚合物(PVDF/ACM)共混材料,为提高其导电及导热性能,于其中引入了碳纳米管(CNT),系统研究了PVDF/ACM/CNT三元体系纳米复合材料的导热及导电性能。结果表明,碳纳米管在PVDF/ACM体系中分散均匀;在基本保持其形状记忆性能的前提下,碳纳米管的加入使材料导热性能及导电性能有较大程度的提高:质量分数为4%的CNT使材料25℃的电阻值降低至5000Ω/square,导热系数提高至0.157 W/(m·K)。 相似文献
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以聚苯乙烯(PS)和锌盐中和的磺化聚苯乙烯(Zn-SPS)膜为基体, 在超临界二氧化碳(SC-CO2)环境中用化学氧化法原位制备了聚吡咯(PPy)导电复合材料. 由于SC-CO2对聚合物基体的强溶胀作用, 吡咯分子高效地扩散到基体内部进行聚合而形成导电通路, 得到比传统的水溶液法更高的电导率. 聚合物基体的性质对复合材料的导电性和形貌产生重要影响. 在相同条件下, Zn-SPS/PPy的电导率比PS/PPy高3~4个数量级, 而它们的体积逾渗阈值分别为2.7%和6.2%, 远远低于理论预测值(16%). 相似文献
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二氧化锡填充多壁碳纳米管材料的制备及电化学性能 总被引:1,自引:0,他引:1
用硝酸氧化法处理多壁碳纳米管(MWCNTs), 使得MWCNTs端口打开, 长度变短, 表面得到改性. 通过二氯化锡与硝酸银反应, 过滤后的溶液在浓硝酸环境中, Sn2+在毛细作用下扩散进入碳纳米管管腔, 吸附、成核并在热处理作用下沉积, 从而制备出SnO2/MWCNTs纳米复合材料. XRD和TEM测试表明, 部分SnO2填充到MWCNTs管腔, 形成不连续的纳米颗粒. 电化学测试表明, SnO2填充的MWCNTs可以结合两者的优势, 使得复合材料的循环性能和比容量均有所改善. 相似文献
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接枝聚苯乙烯/多壁碳纳米管纳米复合材料制备及合成机理 总被引:2,自引:0,他引:2
通过原位悬浮聚合的方法, 以过氧化苯甲酰(BPO)做引发剂, 制备了聚苯乙烯/多壁碳纳米管(MWNT-g-PS)纳米复合材料, 复合材料在水和乙醇中均表现出良好的分散性及稳定性. 通过高倍透射电镜(HRTEM)、场发射扫描电镜(FESEM)分析, 多壁碳纳米管上包覆有1~3 nm的聚苯乙烯膜, 并分布有半径从几十纳米到几百纳米不等的聚苯乙烯微球. 通过傅立叶变换红外光谱(FTIR)、拉曼光谱(Raman spectroscopy)、X光电子能谱(XPS)和热重分析(TGA)对复合材料进行分析, 结果表明, 自由基将多壁碳纳米管表面π键打开, 形成一种新的自由基, 引发聚苯乙烯的自由基聚合, 形成了接枝聚苯乙烯/多壁碳纳米管纳米复合材料. 相似文献
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Dr. Kunpeng Ruan Prof. Xuetao Shi Dr. Yali Zhang Dr. Yongqiang Guo Dr. Xiao Zhong Prof. Junwei Gu 《Angewandte Chemie (International ed. in English)》2023,62(38):e202309010
The positive liquid crystals, 4′-heptyl-4-biphenylcarbonitrile (7CB), are used to functionalize carbon nanotubes (LC-CNT), which can be aligned in the liquid crystalline polyimide (LC-PI) matrix under an alternating electric field to fabricate the thermally conductive LC-CNT/LC-PI composite films. The efficient establishment of thermal conduction pathways in thermally conductive LC-CNT/LC-PI composite films with a low amount of LC-CNT is achieved through the oriented alignment of LC-CNT within the LC-PI matrix. When the mass fraction of LC-CNT is 15 wt %, the in-plane thermal conductivity coefficient (λ∥) and the through-plane thermal conductivity coefficient (λ⊥) of the LC-CNT/LC-PI composite films reach 4.02 W/(m ⋅ K) and 0.55 W/(m⋅K), which are 90.5 % and 71.9 % higher than those of the intrinsically thermally conductive LC-PI films respectively, also 28.8 % and 5.8 % higher than those of the CNT/LC-PI composite films respectively. Meanwhile, the thermally conductive LC-CNT/LC-PI composite films also possess excellent mechanical and heat resistance properties. The Young's modulus and the heat resistance index are 2.3 GPa and 297.7 °C, respectively, which are higher than the intrinsically thermally conductive LC-PI films and the thermally conductive CNT/LC-PI composite films under the same amount of CNT. 相似文献
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Summary: Nanocomposites of ultra-high molecular weight polyethylene (UHMWPE) filled with multi-walled carbon nanotubes (CNT) were obtained by in situ polymerization of ethylene by TpTiCl2Et. This novel catalytic complex activated with polymethylaluminoxane (P-MAO) (Al:Ti = 200) allowed to incorporate the CNT at different compositions (0,1-1 w/w %) into the UHMWPE matrix. The filler addition produced an important enhancement of the catalytic activity when it was compared to that of homogeneous ethylene polymerization carried out under the same experimental conditions (30 min; 1bar; 25 °C). This fact was attributed to in situ support of TpTiCl2Et onto the CNT surface, which not only could induce the stabilization of the catalytic system but also allowed the growing of polymeric chains around the CNT structures. The characterization of these nanocomposites was carried out by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Thermal analysis showed that the incorporation of CNT (at the tested concentrations) did not produce changes in the polymer thermal stability, as revealed by the initial degradation temperature values. However, the CNT produced a nucleating effect in the crystallization of UHMWPE as observed by DSC, independently of the filler content. The crystallization temperature of the obtained nanocomposites increased and the crystallinity degree slightly increased as well. 相似文献
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LUO Pei-wen YU Jian-guo SHI Zhi-qiang HUANG Hua LIU Lang ZHAO Yong-nan LI Guo-dong ZOU Yong-cun 《高等学校化学研究》2012,28(5):780-783
Fe2O3/active carbon(Fe2O3/AC) nanocomposites were readily fabricated by pyrolyzing Fe3+ impregnated active carbon in a nitrogen atmosphere. The as-prepared composites were studied by X-ray powder diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM). The capacitive property of the composites was investigated by cyclic voltammetry(CV) and galvanostatic charge-discharge test. Physical characterizations show that the γ-Fe2O3 fine grains dispersed in the AC well, with a mean size of 21.24 nm. Electrochemical tests in 6 mol/L KOH solutions indicate that the as-prepared nanocomposites exhibited improved capacitive properties. The specific capacitance(SC) of Fe2O3/AC nanocomposites was up to 188.4 F/g that was derived from both electrochemical double-layer capacitance and pseudo-capacitance, which was 78% larger than that of pristine AC. A symmetric capacitor with Fe2O3/AC nanocomposites as electrode showed an excellent cycling stability. The SC was only reduced by a factor of 9.2% after 2000 cycles at a current density of 1 A/g. 相似文献
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镍基板上低温合成定向纳米碳管 总被引:1,自引:0,他引:1
纳米碳管具有非常优异的场发射效应 ,亮度高、均匀且稳定的纳米碳管场效应发射器 ,例如平板显示器、阴极射线管以及信号灯等有着非常广阔的应用前景 [1] .由于纳米碳管的场发射效应与纳米碳管的方向性有关[2 ] ,因此定向纳米碳管的制备及其场发射性能研究是当前的一个研究热点 相似文献
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采用悬浮聚合、炭化、活化制得碳纳米管/活性炭复合微球; 而后利用重氮盐偶合法将对氨基苯磺酸接枝到此复合微球上, 得到磺化碳纳米管/活性炭复合微球; 将其用于吸附血清中的低密度脂蛋白(LDL). 结果表明: 所制备的磺化碳纳米管/活性炭复合微球球形度好, 表面光洁, 中孔发达, 并且接枝有对氨基苯磺酸. 此复合微球对LDL的吸附量随着碳纳米管加入量的增加而逐渐增大; 当碳纳米管加入量为45% (w)时, LDL吸附量达6.564 mg·g-1, 是未添加碳纳米管的3.3倍. 此复合微球在作为血液灌流LDL吸附剂方面有较好的应用前景. 相似文献
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《Analytical letters》2012,45(7):1226-1240
In this paper, we described a novel sensor based on tiron-doped polypyrrole and carbon nanotubes (CNTs) fabricated on low resistance monolayer-modified glassy carbon electrode. First, the dodecylamine monolayer was chemically modified. Second, CNTs were controllably adsorbed onto dodecylamine. Then, tiron doped polypyrrole was electro-deposited on the CNTs film. The layer-by-layer modified electrode was sensitive to dopamine, while it made no response to even high concentration of ascorbic acid. Parameters influencing the dopamine response were optimized. High performance of the sensor was obtained, such as wide concentration range, low detection limit (3 nM), low background current, high stability, and reproducibility. 相似文献