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1.
以不同比例将普通石墨与膨胀石墨添加到普通蛋白泡沫中,观察不同添加量对泡沫稳定性和耐热性能的影响,确定石墨与蛋白泡沫最佳添加量。根据普通石墨与膨胀石墨的特点,用控制变量法找到普通石墨与膨胀石墨的最佳配比,使泡沫具有最佳发泡率、稳定性与耐热性能。  相似文献   

2.
{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the electrolyte (1 mol/L lithium hexafluorophosphate (LiPF6)/ethylene carbonate (EC):diethylene carbonate (DEC):dimethyl carbonate (DMC), 1:1:1) with different contents of TESM2 were characterized by ionic conductivity measurement, galvanostatic charge/discharge test of graphite/Li half cells, and electrochemical impedance spectroscopy. Both the cycling performances and C-rate capabilities of graphite/Li half cells were significantly improved with an optimized content of 15% TESM2 in the electrolyte. The graphite/Li half cell delivered a very high specific capacity of 370 mAh/g at 0.2C rate without any capacity loss for 60 cycles, and retained a capacity of 292 mAh/g at 2C rate. The solid electrolyte interphase (SEI) film on the surface of the graphite anode was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), indicating that TESM2 was effectively involved in the formation of SEI film on the surface of graphite.  相似文献   

3.
采用溶胶-凝胶法制备了膨胀石墨负载TiO2和负载氮掺杂TiO2(N-TiO2)光催化剂,用XRD和SEM对样品进行表征,并以甲基橙溶液为目标降解物进行光催化性能的评价。结果表明:纳米TiO2可牢固地负载在膨胀石墨表面和层间,当达到吸附平衡后,煅烧温度为500℃条件下制备的膨胀石墨负载N-TiO2光催化剂在加入量为10 g/L、反应时间60 min的条件下,对初始浓度为15 mg/L的甲基橙溶液的降解率达到95.2%。  相似文献   

4.
采用常压吸附法研究了膨胀石墨吸附剂在二氧化碳/氮气体系中对二氧化碳的动态吸附性能,比较了其吸附量、穿透曲线和吸附性能的差异.研究了膨胀石墨的比表面积,孔径分布等因素对其二氧化碳吸附性能的影响.结果表明:膨胀体积越大的膨胀石墨,其对二氧化碳的吸附能力越强,最高可达190 mg/g以上.其吸附量随温度升高而呈现下降趋势,但在30℃时吸附量仍达到90 mg/g以上.  相似文献   

5.
INTRODUCTIONIthadbeenwellknownfordecadesthatcar bonnanofiberscanbepreparedbythecatalyticdecompositionofhydrocarbonsandcarbonmonoxidesonthesurfaceofcertainmetals,suchasFe ,Co ,Niandsomeoftheiralloys,inhy drogenatmosphere (Bakeretal.,1 972 ;Oberinetal.,1 976;Oyaeta…  相似文献   

6.
Bundles of pure carbon nanofibers were prepared by catalytic decomposition of acetylene on foam Ni. The morphological and structural characteristics of the carbon nanostructures, in the as-prepared state, were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HTEM). A special conformation of carbon nanofibers composed of segmented structures was found among the products by both SEM and TEM observations. Further HTEM examination indicated that the segments were stacked with well ordered graphite platelets arranged perpendicular to the axis of the filaments. Project supported by NSFC(Grant Nos 107202 n 19920 and 59872030)  相似文献   

7.
用直接混合法制备了碳原子线修饰碳糊电极,并研究了对苯二酚在该电极上的电化学行为.与未加碳原子线的空白碳糊电极相比,碳原子线修饰碳糊电极可使对苯二酚的氧化峰负移0.152V,还原峰正移0.161V,ΔEp减小了0.313V,反应的可逆性明显变好,说明该电极具有具有较高的电催化活性.同时还探讨了电解质溶液、浓度、扫描速率等因素对电催化性能的影响.  相似文献   

8.
采用了E-44环氧树脂与柔性固化剂邻苯二甲酸酐和粉末石墨混合且加热模压同时进行的成型工艺制备出复合材料双极板。该方法采用流体环氧树脂且加热模压同时进行一次性完成复合材料双极板的成形。本研究利用万能材料测试机采用三点弯曲法对不同混合比例样品做了力学性能分析;热重实验验证了该样品在工作条件下的稳定性;SEM扫描电镜分析观察了其微观组织情况。结果表明本文工艺方案所制备样品性能要优于采用聚酰胺固化剂制备所得样品。  相似文献   

9.
采用浸渍法在二氧化硅多孔材料中负载壳聚糖制备壳聚糖/SiO2复合材料,通过X射线衍射、扫描电子显微镜、傅立叶变换红外光谱等方法对所制备材料的组成与结构进行了表征,采用热重-差示扫描量热法研究了复合材料的热稳定性,采用电流中断法测定所制备材料的电导率来衡量其质子传导性能,并考察了壳聚糖溶液浓度对壳聚糖/SiO2复合材料导电性能的影响。结果表明,壳聚糖/SiO2复合材料具有较高的热稳定性,复合材料的电导率随着壳聚糖乙酸溶液浓度的增加而增加,当壳聚糖乙酸溶液质量百分比浓度为2.5%时,电导率可达1.82 S/cm。  相似文献   

10.
Cao  Zongjie  Liu  Huitian  Huang  Wenlong  Chen  Peng  Liu  Yuansheng  Yu  Yu  Shan  Zhongqiang  Meng  Shuxian 《天津大学学报(英文版)》2020,26(1):13-21
The practical application of silica-based composites as an alternative to commercial graphite anode materials is hampered by their large volumetric expansion,poor conductivity,and low Coulombic efficiency.In this work,a novel silica/oxidized mesocarbon microbead/amorphous carbon(SiO_2/O'MCMB/C) hierarchical structure in which SiO_2 is sandwiched between spherical graphite and amorphous carbon shell was succes sfully fabricated through hydrogen bonding-assisted self-assembly and post-carbon coating method.The obtained three-layer hierarchical structure effectively accommodates the volumetric expansion of SiO_2 and significantly enhances the electronic conductivity of composite materials.Moreover,the outer layer of amorphous carbon effectively increases the diffusion rate of lithium ions and promotes the formation of stable SEI film.As a result,the SiO_2/O'MCMB/C composite exhibits superior electrochemical performance with a reversible capacity of 459.5 mA h/g in the first cycle,and the corresponding Coulombic efficiency is 62.8%.After 300 cycles,the capacity climbs to around 600 mA h/g.This synthetic route provides an efficient method for preparing SiO_2 supported on graphite with excellent electrochemical performance,which is likely to promote its commercial applications.  相似文献   

11.
以水热法制备的掺杂不同量稀土La的铁钴合金/钴铁氧体纳米复合物为前驱体,通过与三聚氰胺在高纯氮气氛中发生固相反应合成出掺杂稀土La的Fe-Co合金/石墨纳米复合物。XRD表征结果显示,La与Fe,Co形成了体心立方(bcc)结构的合金;由TEM,HRTEM观察出,掺杂La的Fe-Co合金纳米颗粒尺寸范围为200500nm,且被石墨层包覆;VSM室温磁性能测试结果说明,掺杂La的Fe-Co合金/石墨纳米复合物的饱和磁化强度随着La的掺杂量的增大先减小后增大,而矫顽力先增大后减小。  相似文献   

12.
A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental scanning electron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous nodes. The calcium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose and smooth. Project (No. 2001BA744C) supported by the 10th Five-year National Key Technologies R & D Program, China  相似文献   

13.
碳的纳米材料种类多样,文章对结构化学中碳的纳米材料教学内容进行了拓展。通过介绍纳米金刚石、富勒烯、碳纳米管、石墨烯和石墨炔的结构、性质及应用,达到有效激发学生学习兴趣、开阔学生视野和提升学生综合素质能力的目的。  相似文献   

14.
To examine the effects of co-culture with bone marrow mesenchymal stem cells on expansion of hematopoietic stem/progenitor cells and the capacities of rapid neutrophil engraftment and hematopoietic reconstitution of the expanded cells, we expanded mononuclear cells (MNCs) and CD34+/c-kit+ cells from mouse bone marrow and transplanted the expanded cells into the irradiated mice. MNCs were isolated from mouse bone marrow and CD34+/c-kit+ cells were selected from MNCs by using MoFlo Cell Sorter. MNCs and CD34+/c-kit+ cells were co-cultured with mouse bone marrow-derived mesenchymal stem cells (MSCs) under a two-step expansion. The expanded cells were then transplanted into sublethally irradiated BDF1 mice. Results showed that the co-culture with MSCs resulted in expansions of median total nucleated cells, CD34+ cells, GM-CFC and HPP-CFC respectively by 10.8-, 4.8-, 65.9- and 38.8-fold for the mononuclear cell culture, and respectively by 76.1-, 2.9-, 71.7- and 51.8-fold for the CD34+/c-kit+ cell culture. The expanded cells could rapidly engraft in the sublethally irradiated mice and reconstitute their hematopoiesis. Co-cultures with MSCs in conjunction with two-step expansion increased expansions of total nucleated cells, GM-CFC and HPP-CFC, which led us to conclude MSCs may create favorable environment for expansions of hematopoietic stem/progenitor cells. The availability of increased numbers of expanded cells by the co-culture with MSCs may result in more rapid engraftment of neutrophils following infusion to transplant recipients. Project supported by NIH-Blood, Heart & Lung (National Institute of Health, USA, IR 01 4L70593-01) and Zhejiang Provincial Science Foundation (No. 011103397), China  相似文献   

15.
以正硅酸乙酯和蔗糖为原料,采用液相法制备了SiO/C复合负极材料。通过XRD、SEM以及恒流充放电测试等方法研究了煅烧温度、溶液pH值对SiO/C材料的相组成、颗粒形貌及电化学性能的影响。结果表明,煅烧温度为800℃、pH=6时制备的SiO/C负极材料具有高的可逆比容量(~500mAh/g)及优良的循环性能。这主要是由于煅烧温度为800℃时材料中无定形碳的碳化程度较高,pH=6时可形成较小的SiO核心颗粒。  相似文献   

16.
将窄带隙的Ti2O3负载在由生长碳纳米线阵列的碳毡制成的多级碳基底上制得新型光热转换材料(Ti2O3@CA/CF),考虑了亲水性、电解沉积电位、Ti2O3负载量等因素,为材料的制备提出了最佳的方法。然后用扫描电子显微镜、紫外可见光谱和电化学活性比表面积对样品的物化性质进行了表征,并对制得的Ti2O3碳基底材料的光热性能进行了实验测试。结果表明,Ti2O3@CA/CF具有高达71.9%的光热转换效率以及较高的蒸发率和对各种水体和光强的适应性。  相似文献   

17.
通过对苝-3,4,9,10-四羧酸二酐(PTCDA)酸化,合成了苝-3,4,9,10-四羧酸(PTCA),采用红外、氢谱等方法对目标产物进行了表征.并且采用荧光光谱研究了产物的光学性质,结果表明:酸化后的PTCA表现出很强的荧光特性.为了进一步揭示分子作用机制,以高定向热解石墨HOPG(Highly Oriented Pyrolytic Graphite)为基底,利用扫描隧道显微镜(STM)研究了PTCA分子在固-液界面的二维(2D)自组装行为,实验结果表明了分子间的作用力来源于分子间的氢键和π-π堆积相互作用力.  相似文献   

18.
以吐温80为分散剂,分别以丙烯酰胺和N,N’-亚甲基双丙烯酰胺为单体和交联剂,制备中间相碳微球/石墨(MCMB/G)浆料,采用凝胶注模工艺,制得直接醇类燃料电池管状阴极支撑体素坯,经液态干燥、滚动干燥和埋石墨粉烧结等过程处理制得其样品。所制备的直接醇类燃料电池管状阴极支撑体物理性能为:孔隙率42.7%,电阻率0.0276Ω·cm,抗折强度6.23 MPa,抗压强度16.29 MPa,具有收缩率低、变形量小、石墨化度高、电导率高、力学性能好等特点。  相似文献   

19.
防止石墨电极高温氧化的实验研究   总被引:2,自引:0,他引:2  
通过对石墨电极高温防氧化失重实验,对石墨电极高温防氧化机理进行了初步研究。采取向电极表面直接喷淋防氧化溶液的方法,迅速降低石墨电极表面温度,并在电极表面生成连续、均匀的防氧化膜,显著提高石墨电极高温抗氧化能力,达到降低石墨电极消耗的目的。  相似文献   

20.
本文研究了过滤式阴极电弧沉积方法获得的类金刚石薄膜.实验研究电弧的稳定性和探针电流与沉积参数的关系,并系统研究了膜层的性能.膜层的摩擦性能也得到了研究.  相似文献   

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