共查询到19条相似文献,搜索用时 46 毫秒
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为提高金属有机骨架材料ZIF-8(Zn(Hmim)2,Hmim=2-甲基咪唑)的性能及扩展其应用范围,以石墨烯气凝胶微球(rGOAM)为载体,将ZIF-8均匀负载于石墨烯片层上,制得ZIF-8/石墨烯复合气凝胶微球(ZIF/rGOAM).首先通过静电喷雾结合热/微波还原得到2种多孔、疏水的rGOAM,然后采用原位生长的... 相似文献
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以硅溶胶为原料,通过W/O乳液法结合溶胶-凝胶过程制备SiO_2气凝胶微球。在硅溶胶中掺杂氧化石墨烯(GO),经过洗涤、溶剂替换、表面改性、真空干燥制备出掺杂量不同的氧化石墨烯/SiO_2复合气凝胶微球(GOS-CAMs),最后经高温处理得到石墨烯/SiO_2复合气凝胶微球(GS-CAMs)。经过堆密度、氮气吸附-脱附、扫描电子显微镜及傅里叶变换红外光谱等测试,选择GO掺杂量为0.4%(wt,质量分数,下同)的GS-CAMs,分别与石墨烯、SiO_2气凝胶微球进行对比,研究其在不同温度下对水溶液中不同浓度甲苯的吸附性能,并从吸附热力学、吸附动力学探讨其吸附机理。结果表明:掺杂量为0.4%的GO制备的GS-CAMs的综合性能最好,其松散堆密度为300kg/m~3,比表面积、平均孔径分别为328m~2/g、31.23nm;与纯SiO_2气凝胶微球相比,GS-CAMs的比表面积、孔径明显增加;GS-CAMs对不同温度下不同浓度甲苯水溶液的最大饱和吸附量为211mg/g,约为SiO_2气凝胶微球、石墨烯吸附量的1.2倍、1.6倍。吸附过程符合Langmuir等温吸附模型和准二级动力学模型。 相似文献
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以正硅酸乙酯(TEOS)为先驱体制备硅溶胶,再以硅油为分散介质,在吐温80为乳化剂的油相与SiO2溶胶为水相的乳化体系中,应用雾化法和乳液成球技术制备微米级SiO2凝胶小球,然后,通过超临界CO2干燥技术制备微米级siO2气凝胶小球,用光学显微镜、SEM、红外光谱(FT—IR)及cBET技术对其表征,结果表明,微米及SiO2气凝胶小球表观粒径较为均匀,平均粒径约为30μm,密度为216kg/m2,平均孔径6.72nm,BET比表面积为802.35m2/g,孔体积为1.15cm3/g,是一种具有典型气凝胶结构的微粒状轻质纳米多孔材料。 相似文献
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为拓展SiO2气凝胶的应用范围和效率,弥补SiO2气凝胶微球制备技术中的不足,以水玻璃为硅源采用液滴成球工艺在单一油相中制备了直径为毫米级别的SiO2气凝胶微球,并研究了微球原始粒径和干燥工艺对其线性收缩率的影响,结果表明微球收缩率随原始粒径的减小而降低,干燥工艺不同收缩率也有差异.经三甲基氯硅烷(TMCS)表面改性后再超临界干燥的样品收缩率最小,射线衍射(XRD)和孔隙度分析仪对其测试表明为无定型结构,所有孔径均<80nm,平均孔径为5.5nm,比表面积为181m2/g. 相似文献
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研究硅溶胶的雾化方法和形成油包水的乳化体系,在乳化体系中加入凝胶剂制备SiO2湿凝胶微球。制得的湿凝胶微球在常温常压下老化3d后用过滤的方法分离湿凝胶微球和油相;用正己烷清洗微球表面的油和杂质,用乙醇除去湿凝胶微球内部的水;最后,用超临界CO2的方法干燥湿凝胶微球得到SiO2气凝胶微球。研究结果表明,该方法最大的优点是可以大规模化制备气凝胶微球,制得的气凝胶微球直径<50μm,大部分集中在15~35μm之间。SiO2气凝胶微球具有明显的介孔材料特征,孔径为10nm左右,比表面积高达846.14m2/g,堆积密度约为221kg/m3。 相似文献
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环糊精基石墨烯气凝胶的制备及其气体吸附性能研究 总被引:1,自引:0,他引:1
以氧化石墨烯(GO)为骨架,β-环糊精(β-CD)为交联剂,采用一步水热法成功制备了结构均匀的环糊精基石墨烯气凝胶(C-GAs)。采用比表面及孔径分析仪对样品的孔隙结构进行了表征,并进一步研究了其孔隙结构对二氧化碳(CO_2)、氢气(H_2)和甲烷(CH_4)气体的吸附性能的影响。结果显示,在β-CD∶GO的质量配合比为0.5∶1条件下,C-GAs拥有较高的比表面积537m~2/g和总孔容0.750m~3/g,显示了其极好的结构特性,在298℃,1.0Pa条件下,C-GAs对CO_2的吸附量达到44.73mg/g,对CH_4的吸附量达到6.82mg/g;在77℃,1.0Pa条件下,C-GAs对H_2的吸附量达到1.17mg/g,制备的C-GAs对CO_2具有较强的吸附能力以及良好的吸附选择性,且制备过程简单、绿色、安全。 相似文献
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SiO2气凝胶是一种含有纳米介孔结构的轻质固体材料,具有高孔隙率、高比表面积、低导热性、低介电性等特性,在隔热、吸附、吸声、发光、催化、电子等工业领域具有广阔的应用前景。但SiO2气凝胶自身孔结构存在易碎、易坍塌等缺陷,导致应用受到较大限制。在保持SiO2气凝胶良好特性的前提下,对其进行增强改性制备力学性能优良的SiO2气凝胶复合材料是近年来的研究热点。本文报道了无机/有机纤维增强改性SiO2气凝胶、有机聚合物增强改性SiO2气凝胶及无机物掺杂增强改性SiO2气凝胶等复合材料的主要制备工艺过程、材料综合性能表现及增强改性机制,探讨了增强改性SiO2气凝胶复合材料研究进展及重点方向,以期为增强改性SiO2气凝胶复合材料的研究和应用提供新的设计思路。 相似文献
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Two-dimensional graphene film exhibits sluggish ion diffusivity while three-dimensional(3D)graphene aerogel has low packing density and poor mechanical flexibility.Consequently,there is an urgent need for graphenebased film with both mechanical robustness and high specific capacitance.Here,we present an easy and scalable strategy for fabricating a free-standing flexible graphene-based aerogel film electrode with a two-layered structure,in which the top layer is an interconnected macroporous reduced graphene oxide/carbon nanotube(RGO/CNT)aerogel,and the bottom layer is a flexible electrospun polyacrylonitrile(PAN)nanofiber membrane.The porous 3D structure of the aerogel provides fast transport of electrolyte ions and electrons,while the nanofiber membrane provides both strong support for the aerogel and mechanical flexibility.Polypyrrole(PPy)can be uniformly loaded on RGO/CNT/PAN(RCP)composite aerogel film to provide pseudocapacitance,and nitrogen-doped RGO/CNT/carbon nanofiber(NRCC)aerogel film can be obtained by further pyrolysis.The resultant RCP@PPy-0.05//NRCC based asymmetric supercapacitor can have a maximum voltage of 1.7 V and a maximum energy density of 60.6 W h kg-1at 850.2 W kg-1.This indicates that free-standing graphene-based aerogel film can be used in flexible supercapacitors. 相似文献
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Jintawat Chaichanawong Koranit Kongcharoen Surat Areerat 《Advanced Powder Technology》2013,24(5):891-896
Carbon aerogel microspheres were successfully prepared using a simple-injection emulsification method, employing sol–gel polycondensation of a resorcinol–formaldehyde solution containing sodium carbonate as a catalyst. This process was followed by solvent exchange using acetone, supercritical drying with carbon dioxide and carbonization in a nitrogen atmosphere. The effect of curing time before starting injection, injection rate and agitation rate of continuous phase on the particle size and the porous properties of the carbon aerogel microspheres was investigated. Adsorption of phenol by using the prepared carbon aerogel microspheres was also examined. The diameter of carbon aerogel microspheres was controlled in the range of 20–55 μm by varying injection rate and agitation rate. The mean diameter of carbon aerogel microspheres decreased with increasing the injection rate and the agitation rate, whereas their mean diameter was independent of the curing time. The BET surface area and total pore volume of carbon aerogel microspheres increased with increasing the curing time. In contrast, their BET surface area and total pore volume decreased with increasing the injection rate and the agitation rate. The BET surface area, total pore volume, mesopore volume and micropore volume of the carbon aerogel microspheres with a mean diameter of 45 μm were 903 m2/g, 0.60 cm3/g, 0.31 cm3/g and 0.27 cm3/g, respectively. The phenol-adsorption capacity of these carbon aerogel microspheres was 29.3 mg phenol/g adsorbent. 相似文献