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中间相沥青基泡沫炭的制备、结构及性能 总被引:3,自引:0,他引:3
以萘系中间相沥青为原料,考察了发泡条件、炭化和石墨化工艺对所制泡沫炭结构和性能的影响.结合粘温曲线、TG-DTG热重曲线以及不同发泡条件下泡沫炭的表面形貌分析,其最佳发泡条件为:发泡温度600℃,升温速率5℃/min,发泡压力5MPa.石墨化升温速率越低越有利于泡沫炭石墨微晶的生长及压缩强度的提高,其中以5℃/min升温至2800℃并恒温30min所制泡沫炭的压缩强度达1.38MPa. 相似文献
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以AR中间相沥青为原料,采用中间相沥青自发泡法在发泡压力为0.1、3.0MPa,发泡温度为450℃的条件下制备了两种不同体积密度的炭泡沫CF-1和CF-2.将CF-1经过10h和70h化学气相沉积热解炭(CVDPyC)处理后得到炭泡沫CF-1-PC1和CF-1-PC2.测定了炭泡沫的抗压强度和导热系数,利用SEM和光学显微镜观察了炭泡沫的孔结构,考察了CVD PyC对炭泡沫结构及性能的影响.研究结果表明,CVD PyC处理可以增加炭泡沫韧带宽度,封填孔壁微裂纹;沥青炭和热解炭之间无明显界面,结合良好;经过CVD PyC处理后得到的CF-1-PC1和CF-1-PC2的体积密度、抗压强度、导热系数分别为, 0.196g·cm-3、1.89MPa、0.314W·m-1·K-1和0.461g·cm-3、11.93MPa、1.581W·m-1·K-1. 相似文献
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中间相沥青基泡沫炭的制备与结构表征 总被引:11,自引:0,他引:11
将石油系中间相沥青利用限定尺寸法发泡后获得了泡沫炭,泡沫炭再经氧化、炭化和石墨化处理获得了具有良好孔结构的泡沫炭.利用SEM和XRD分析了泡沫炭的形态和结构.发现调整发泡模具中的自由空间可以控制泡沫炭的孔径;炭化和石墨化后泡沫炭的孔径减小,孔壁片层取向接近石墨;泡沫炭的孔壁由平直孔壁和“Y”形孔壁结构成,前者内部片层取向优于后者.大孔径泡沫炭的孔壁具有更紧密的内部分子排列,但其微晶尺寸较小. 相似文献
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中间相沥青基炭泡沫体的制备、结构及性能 总被引:12,自引:4,他引:12
以合成中间相萘沥青为原料,采用加压发泡法制备孔径均匀的初生炭泡沫体,经700℃~1000℃和2300℃~2800℃热处理制备出炭化和石墨化炭泡沫体;以700℃炭化处理所得的炭泡沫体作为芯材制成夹芯复合材料。研究了原料性能、发泡以及热处理工艺参数对炭泡沫微观结构和力学性能的影响,考察了炭泡沫体夹芯复合材料的微波吸收性能。结果表明:发泡过程中保持均匀的温度场是制备孔径均匀的炭泡沫体的关键因素,压力是影响孔结构的主要因素。炭泡沫体的微晶结构、力学性能以及微波吸收性能沿xy和XZ面方向(分别表示垂直和平行于重力方向)具有各向异性。 相似文献
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加热条件对炭泡沫材料孔结构和性能的影响 总被引:2,自引:0,他引:2
以AR沥青为原料,利用高压釜在不同恒温条件下制备了炭泡沫,并测定了其孔结构、体积密度、显气孔率、压缩强度、常温热导率以及微晶参数.结果表明:相对于短恒温时间,长恒温时间制得的炭泡沫孔径大(412nm)、显气孔率高(83.82%)、体积密度小(0.34g/cm~3)、压缩强度高(4.92MPa),多孔连通结构更丰富.经过石墨化处理后,石墨泡沫呈现出较高的常温热导率(71.34W/(m·K))和较小的层片间距d_(002)(0.33556nm).石墨泡沫的常温比导热率能达到210(W·(m·K)~(-1)) /(g·cm~(-3)),是铜的5倍,铝的4倍. 相似文献
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前驱体对炭泡沫孔结构的影响 总被引:3,自引:0,他引:3
分别以煤沥青、石油中间相沥青和AR沥青为前驱体制备炭泡沫材料。采用GPC测定前驱体分子量,SEM观察所制炭泡沫的孔结构,光学显微镜测量所制炭泡沫的孔径及其分布。结果发现,由于煤焦油沥青不含中间相,且QI含量较高,导致在实验条件下不能直接制备出合格的炭泡沫。以石油中间相沥青和AR沥青为原料均能制备出具有分布均匀开孔结构,且微观各向异性的炭泡沫。由AR沥青制备的炭泡沫呈现平均孔径较小(212μm)、孔壁较薄、孔径分布较窄(180μm~300μm)、开孔率较高、以及韧带排列较规整等特点,表明低QI含量、低分子量且分布较窄的前驱体有利于发泡。 相似文献
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Parkpoom Lorjai Sujitra Wongkasemjit Thanyalak Chaisuwan 《Materials Science and Engineering: A》2009,527(1-2):77-84
An organic foam derived from a new type of phenolic resin, namely polybenzoxazine, was successfully prepared with a noncomplex and economical foaming method by using azodicarbonamide (AZD) as a foaming agent. The influence of foam density on the physical and mechanical properties of the foams was studied. All resulting polybenzoxazine foams and carbon foams exhibit a tailorable uniform microstructure. Polybenzoxazine foams showed a density in the range of 273–407 kg/m3, and a compressive strength and a compressive modulus in the range of 5.2–12.4 MPa and 268–681 MPa, respectively. The foam density not only affects the physical and mechanical properties, but also affects the deformation response of the foam. In addition, the polybenzoxazine foam was further transformed into carbon foam by carbonization at 800 °C under an inert atmosphere, and its properties were examined. 相似文献
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研究了以中间相炭微球为原料,羧甲基纤维素为添加剂制备管式炭膜过程中膜孔的形成及控制.扫描电子显微镜(SEM)分析表明,炭膜中的孔隙主要是由微球堆积的间隙和粘结剂高温分解形成的.热重分析(TG)和气泡法孔径测试结果表明,随着添加剂用量的减少和升温速率的提高,炭膜孔径减小;同时低于800℃炭化处理能够显著增加炭膜孔径.浸渍液浓度的增加和浸渍次数的增加均能减小炭膜平均孔径,说明制备工艺条件的控制是调整膜孔结构的有效手段. 相似文献
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AbstractA detailed study is given on the synthesis of a hierarchical porous carbon, possessing both meso- and macropores, using a mesophase pitch (MP) as the carbon precursor. This carbon material is prepared by the nanocasting approach involving the replication of a porous silica monolith (hard templating). While this carbon material has already been tested in energy storage applications, various detailed aspects of its formation and structure are addressed in this study. Scanning electron microscopy (SEM), Hg porosimetry and N2 physisorption are used to characterize the morphology and porosity of the carbon replica. A novel approach for the detailed analysis of wide-angle x-ray scattering (WAXS) from non-graphitic carbons is applied to quantitatively compare the graphene microstructures of carbons prepared using MP and furfuryl alcohol (FA). This WAXS analysis underlines the importance of the carbon precursor in the synthesis of templated porous carbon materials via the nanocasting route. Our study demonstrates that a mesophase pitch is a superior precursor whenever a high-purity, low-micropore-content and well-developed graphene structure is desired. 相似文献
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AbstractMicrocapsules were prepared by in situ polymerization and microcapsulation. Tetraethyl orthosilicate was used as the core material and phenolic resin was used as the wall material in an emulsion system of polyacrylic and tetraethyl orthosilicate. The obtained microcapsules were slowly heated such that the core material was released by evaporation, leaving hollow-core spheres. The spheres were mixed with a phenolic resin-derived binder and molded to obtain a carbon foam precursor, which was carbonized at 1100 °C under the protection of N2 gas and graphitized at 2300 °C under the protection of Ar gas. Thus, the carbon foam of hollow closed-shelled microspheres with a graphitic structure was prepared. The properties and structure of this foam were discussed. 相似文献
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Ke-zhi Li Zhen-hai Shi He-jun Li Zhuo Tian Chuang Wang 《Science and Technology of Advanced Materials》2008,9(2)
Microcapsules were prepared by in situ polymerization and microcapsulation. Tetraethyl orthosilicate was used as the core material and phenolic resin was used as the wall material in an emulsion system of polyacrylic and tetraethyl orthosilicate. The obtained microcapsules were slowly heated such that the core material was released by evaporation, leaving hollow-core spheres. The spheres were mixed with a phenolic resin-derived binder and molded to obtain a carbon foam precursor, which was carbonized at 1100 °C under the protection of N2 gas and graphitized at 2300 °C under the protection of Ar gas. Thus, the carbon foam of hollow closed-shelled microspheres with a graphitic structure was prepared. The properties and structure of this foam were discussed. 相似文献