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71.
聚丙烯/有机蒙脱土纳米复合材的制备及性能研究 总被引:11,自引:0,他引:11
本文采用熔体插层法在双螺杆挤出机中制备了PP/OMMT纳米复合材料,讨论了有机化改性、相容剂以及辐照、接枝处理等因素对纳米复合材料性能的影响。用各种手段(SEM、TEM、DSC和XRD)对所制得的复合材料的形态结构进行表征。研究结果表明:对MMT进行有机化改性、加入适当的相容剂以及进行辐照、接枝处理的确能使复合材料的力学性能有所提高。形态结构表征证明:PP基体与纳米填料间的相容性增加,两者间的界面相互作用得到了加强;OMMT片层在PP基体中达到纳米级的分散。 相似文献
72.
The nanocomposite films were prepared by direct intercalation of poly (ethylene oxide) and PEO into MoO3 xerogel via sol-gel route,The electrochromic behavior and the chemical conditionws of Li^ ions were investigated by cyclic voltammograms,UV-visible spectral transmittance and XPS,The tesults show that the cycling efficiency and the reversibility of insertion/extraciton of Li^ ions in (PEO)1 MoO3 .nH2O nanocomposite film were improved.The intercalation of PEO into MoO3 xerogel modulated the wavelength range of electrochromism and enhanced the electrochromic efficiney,Two different chemical conditions of Li^ ions existing in the interlayer and interstitial positions of MoO3 lattice were observed in MoO3 XEROGEL AND (PEO)1 MoO3.nH2O naocomposite films. 相似文献
73.
锂离子蓄电池技术进展及市场前景 总被引:9,自引:2,他引:9
锂离子蓄电池是以锂离子在碳负极和嵌入化合物正极中的嵌入和脱嵌为原理发展起来的一种新型蓄电池.到目前为止,国外1865型圆柱Li_xC/LIPF_6—EC+DEC/Li_1-xCoO_2锂离子蓄电池的比能量已达到105Wh/kg和270Wh/L.而其月自放电已降至12%以下,在100%DOD和lC率下的循环寿命达到1000次.这种电池已广泛应用于大哥大,摄相机及笔记本计算机等设备中,还有可能在将来应用于电动汽车中作电源. 相似文献
74.
以辽宁某地钙基蒙脱石为原料,经碳酸钠钠化改型后,用十六烷基三甲基溴化铵作插层剂对其进行有机插层处理,考察插层剂的最佳用量。采用XRD技术对所研制的蒙脱石有机插层复合物进行分析,结果表明,插层剂用量为120%mmol/100gCEC时所制备的蒙脱石有机插层复合物的插层效果最好。 相似文献
75.
The superconducting properties of iodine-intercalated high-temperature superconducting Bi2Sr2Ca2Cu3O10+x
phase (Bi-2223) were systematically studied. It was found that for samples containing a significant amount of Bi2Sr2CaCu2O8+x
, iodine intercalation results in the dramatic decrease of the inter-granular critical current density, as well as a significant
decrease of the critical temperature (T
c), the critical current density in the grains (J
cg), and of the amount of Bi-2223. For samples with a large amount of Bi-2223, T
c changes insignificantly, whereas J
cg can even increase. We argue that the different behavior of the superconducting parameters is the result of various oxygen
concentrations, and we explain the effect of iodine intercalation based on the parabolic dependence between T
c and the number of holes per CuO2 layer. The H(T) curves (determined from the peak position in the loss signal of ac susceptibility) for intercalated samples deviate significantly
from the quasi 2D-like behavior, pointing toward an enhancement of the 3D fluctuations of vortices. For the change in the
values and dimensionality of the flux pinning in the process of the intercalation, we attempted a qualitative explanation
based on the models proposed in literature. 相似文献
76.
77.
When milling micrometer thin Nd2Fe14B platelets, of an average 1–2 mm diameter, in toluene in a closed reactor, part of the toluene decomposes at the surface
of the platelets and yields nascent hydrogen and carbon/low hydrocarbons. The hydrogen diffuses into the Nd2Fe14B platelets and the carbon forms a thin surface passivation layer of the platelets, forming the stable Nd2Fe14BH
x
,x ≤ 5, hydride at room temperature. On heating in a calorimeter, the hydrogen desorbs off the sample with a well-defined endotherm
between 370 and 425 K. An N2 gas atmosphere, if used during the heating, facilitates the H-desorption process with the modified kinetic parameters. For
example, the enthalpy of the H-desorption ΔH and the related activation energyE
a have the measured values ΔH = 153 J/g andE
a = 58·2 kJ/mol in argon and ΔH = 256 J/g andE
a = 41·6 kJ/mol in N2. It is argued that N2 gas has a fast reaction with the H atoms desorbing off the thin sample platelets and forms NH3 gas with an instantaneous decrease of the total external gas pressure at the sample. This supports the fast desorption of
H atoms in the sample with the modified desorption kinetics in N2 gas. 相似文献
78.
Mesoporous compound of cobalt-layered manganese oxide was synthesized by self-assembly reaction between 2D manganate nanosheets and cobalt ions. It was found that 2D manganate nanosheets are interstratified with cobalt ions, leading to the formation of porous intercalation heterostructure with expanded surface area of ∼ 44-100 m2/g. The mesopores with the average diameters of ∼ 11-17 nm originate from the house-of-cards type stacking of the layered manganate crystallites. Co K- and Mn K-edge X-ray absorption spectroscopy revealed that both the cobalt and manganese ions are stabilized in octahedral symmetry with the mixed oxidation states of Mn3+/Mn4+ and Co2+/Co3+. Considering high oxidation states of component metal ions, this porous material is expected to be very useful as redox catalysts and/or lithium intercalation electrodes. 相似文献
79.
以新型成炭剂(CFA)、改性聚磷酸铵(MAPP)、乙烯-丙烯酸酯-马来酸酐三元共聚物熔融插层有机蒙脱土(EMH-OMMT)母粒复配成膨胀阻燃剂(IFR),与聚丙烯(PP)共混后通过流延薄膜机制备膨胀阻燃PP薄膜。对其进行了阻燃性能、力学性能测试,并运用热重分析表征了其热分解过程。相比未熔融插层OMMT和传统的4A分子筛协效剂,EMH-OMMT不仅提高了体系的阻燃性能,使薄膜(0.2mm)在IFR添加28%时通过了VTM-0级,而且明显提高了体系的力学性能。 相似文献
80.
将聚酰亚胺(PI)与有机蒙脱土(OMMT)混合,制备了PI/OMMT粉状材料;将粉状材料与丁苯胶乳(SBR)混合,制备了颗粒状PI/OMMT/SBR复合材料.SEM照片显示,有机蒙脱土可改善聚酰亚胺与丁苯橡胶的相容性.X射线衍射(XRD)结果表明,聚酰亚胺分子链与丁苯橡胶分子链一起插入有机蒙脱土层间,使层间距变大;有机蒙脱土作为交联点存在.动态力学性能测试结果表明,在频率扫描下,加入PI/OMMT后丁苯橡胶的G′最高,但tanδ较低. 相似文献