共查询到19条相似文献,搜索用时 93 毫秒
1.
以氧化石墨为前驱体,采用真空热膨胀还原法获得了功能化的石墨烯材料。以石墨烯为纳米填料,采用静电纺丝法制备了一系列石墨烯改性聚丙烯腈(PAN)纳米复合纤维,经进一步预氧化和炭化得到纳米炭纤维。使用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、元素分析(EA)、热重(TGA)和差示扫描量热仪(DSC)研究了石墨烯对纳米炭纤维的宏观性能与微观结构的影响。结果表明,加入石墨烯后,PAN纳米纤维中分子取向变大,结晶度下降。对氧化、环化和脱氢反应可产生一定的抑制作用,导致预氧化反应程度下降。同时,石墨烯可作为炭化阶段微晶生长的晶核,有利于碳网平面的快速生长。 相似文献
2.
以石墨烯为改性剂,醋酸锌为锌源,采用水热合成法制备石墨烯/ZnO纳米复合物。随着石墨烯在反应体系中用量的增加,石墨烯/ZnO纳米复合物的形貌和抗菌性能存在显著差异。m(石墨烯)∶m(ZnO)为0.02时,纳米ZnO在石墨烯片层表面负载分布均一,石墨烯/ZnO纳米复合物尺寸较小,抗菌性能较纯纳米ZnO显著提高,最低抑菌浓度从313μg/mL降至157μg/mL。石墨烯/ZnO纳米复合物涂覆玻璃纸的透光性能优良,对李斯特氏菌和大肠杆菌的抑菌率分别为98.3%和99.1%,可作为新型功能材料用于食品、药品的抗菌包装。 相似文献
3.
以氧化石墨和氯铂酸为前驱体,在油胺中简便地合成了还原氧化石墨烯-铂(Reduced graphene oxide-platinum,rGOPt)纳米复合物,并对其进行了表征。透射电子显微镜和光谱测试结果表明,铂纳米颗粒均匀分布在石墨烯表面,尺寸约为30nm,铂纳米粒子为多孔隙结构,结晶性能良好,氧化石墨在高温下转变为还原氧化石墨烯。用此方法也可以制备还原氧化石墨烯-金(rGO-Au)或还原氧化石墨烯-银(rGO-Ag)的纳米复合物,金、银纳米颗粒呈球状,对可见光具有明显的表面等离子吸收。同时,油胺作为溶剂、贵金属盐的还原剂和表面活性剂,使制备过程简单、快捷。 相似文献
4.
采用水相沉淀聚合-原位法合成银/聚丙烯腈(Ag/PAN)复合物, 通过测定其相对黏度, 系统地考察了反应物配比对Ag/PAN复合物分子量的影响。得到较理想的合成条件为, 丙烯腈(AN)单体浓度10%, AgNO3浓度0.6%, K2S2O8浓度2%。将所得复合物进行预氧化后得到纳米银/环化聚丙烯腈(Ag/C-PAN)复合物。通过FTIR分析复合物的组成, 并得到不同预氧化温度和时间下复合物的相对环化率。采用TEM、XRD等方法对复合物的微观结构进行表征。结果表明, 纳米银均匀地分散于环化聚丙烯腈基体中, 银粒子的晶型为面心立方, 粒径约为10 nm。 相似文献
5.
以氧化石墨烯(GO)为基体,采用界面聚合法制备了聚苯胺纳米纤维/氧化石墨烯的复合物(PA-NI/GO),经水合肼还原和APS再氧化得到聚苯胺纳米纤维/石墨烯复合物(PANI/GR)。用FT-IR、UV-Vis、XRD、SEM和TEM对复合物的结构和形貌进行表征,结果表明氧化石墨烯不仅为苯胺提供了聚合的基体,同时对聚苯胺有掺杂作用,聚苯胺纤维夹在片状石墨烯之间呈现"三明治"结构。通过循环伏安和恒流充放电测试发现,PANI/GR复合材料表现出双电层电容和法拉第赝电容双重特点,受协同效应的作用,在电流密度为400mA/g时,比容量高达460F/g,呈现出优异的电化学活性。 相似文献
6.
POSS/聚丙烯腈星型纳米复合物的制备及热性能 总被引:1,自引:0,他引:1
通过自由基聚合的方法,将八乙烯基多面笼形低聚倍半硅氧烷(POSS)与丙烯腈(AN)共聚合得到不同POSS含量的AN与POSS的共聚物(PAN-POSS)。采用傅立叶红外光谱(FT-IR)、硅核磁共振(~(29)Si-NMR)、X射线衍射(XRD)、热失重分析(TGA)和差示扫描量热(DSC)对PAN-POSS共聚物结构和性能进行了表征。研究结果表明,POSS笼形结构以化学键合的方式分子水平上均匀地分散在杂化聚合物中,形成了星型结构POSS/聚丙烯腈纳米复合物,复合物中POSS的含量随着反应单体中POSS配比的增加而增加,复合物的热性能随POSS含量增加明显提高。 相似文献
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制备了一种单壁碳纳米管担载金纳米颗粒复合材料,利用X射线衍射、扫描透射显微镜、能量色散X射线分析、比表面积分析、激光拉曼光谱和紫外-可见分光光度计等对其结构进行了表征.结果表明:纳米金粒为微晶体,其平均直径为7nm且直径分布范围较窄.研究了该单壁碳纳米管担载金颗粒对仲醇的无溶剂氧化的活性和选择性,发现其转化效率可达95%. 相似文献
9.
目的研究石墨烯/银纳米粒子(AgNP/G)复合抗菌材料简单快捷的制备方法。方法在碱性环境下采用原位还原法制备AgNP/G纳米复合材料。利用X射线衍射、红外、紫外和透射电镜等技术对AgNP/G复合材料的结构及形貌进行表征,探讨其形成机理,并通过平板计数法来观察AgNP/G复合材料的抗菌性能。结果所制备的AgNP/G复合材料中,形成的纳米银尺寸较小(15 nm)、粒径均一,在石墨烯片层上分布均匀。当AgNP/G的抗菌质量浓度为20μg/m L时,抗菌率达到98.7%。结论碱的存在能加速银纳米粒子在石墨烯片层上的形成,得到的AgNP/G复合材料抗菌性能优异。 相似文献
10.
以聚丙烯腈(PAN)为先驱体,N,N-二甲基甲酰胺(DMF)为溶剂配置质量分数10%的PAN溶液进行静电纺丝,输出电压为18 kV,注射流量为3 mL/h,收丝距离为15 cm,得到纳米PAN纤维无纺布,纤维直径为200nm~280nm,所得纤维布柔软有韧性。随后,无纺布经过280℃氧化交联和850℃氮气气氛热解处理,得到质轻柔软的纳米炭纤维无纺布,直径为100nm~200 nm。通过扫描电镜(SEM)、红外光谱(FT-IR)、电子探针显微分析(EPMA)、X射线衍射(XRD)等手段对纳米PAN和炭纤维布的形貌、成分和结构进行了表征。热重(TGA)分析结果表明,PAN基纳米炭纤维最终收率为51%。 相似文献
11.
Mohamed M. Abdel-Mottaleb Shrouk A. Karim Tarek A. Osman Aly Khattab 《先进材料力学与结构力学》2020,27(4):346-351
AbstractMostly, water filters are designed based on the steady state conditions “Laminar flow”, while the actual case is a turbulent flow as a result of chaotic changes in pressure and flow velocity, which can be lead to rapid failure thus decrease its service time. Also, the surface roughness of the synthesized filter was neglected, which has been classified as the main cause of shear failure. In this work, Polyacrylonitrile (PAN) nanofibers were enhanced by graphene oxide (GO) with different fractions in order to increase its performance, in terms of mechanical behavior. At the same time, GO was employed as a surface refining of the synthesized filter in order to decrease the friction between flow and filter surface thus delays the occurrence of shear failure. In this work, PAN/GO composite nanofibers were fabricated by electrospinning process. Different volume concentration of GO (0.05, 0.5, 1, and 1.5?wt%) have been investigated. PAN/GO composite nanofibers were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). As demonstrated by the results of tensile testing, mechanical properties of PAN can be effectively enhanced with the addition of GO filler. At 1?wt% of GO filler nanofibers membranes achieved 64.4% rise of tensile strength and 71.4% improvement of Young’s modulus. 相似文献
12.
将不同比例的氧化石墨烯(GO)和硝酸银混合,采用水合肼一步还原制备石墨烯/纳米银(RGO/Ag)复合材料。采用UV-vis、XRD、FTIR和SEM对RGO/Ag复合材料结构组成进行表征分析,并结合热流量和结构变化研究其构成和热处理工艺对导电性的影响。结果表明:Ag基本以类似球形与石墨烯(RGO)复合;RGO/Ag复合材料的导电性与其构成有很大关系,只有当GO加入量小于50wt%时,Ag含量的提高和热处理工艺的优化可以明显改善复合材料的导电性,其中,GO加入量为16wt%的RGO/Ag片方阻值可达到8mΩ/□;当GO加入量高于50wt%时,复合材料导电性与RGO接近,受Ag含量的提高和热处理工艺优化的影响较小。 相似文献
13.
M. M. Shokrieh S. M. Ghoreishi M. Esmkhani Z. Zhao 《Fatigue & Fracture of Engineering Materials & Structures》2014,37(10):1116-1123
The effects of graphene nanoplatelets (GPLs) and graphene nanosheets (GNSs) on fracture toughness and tensile properties of epoxy resin have been studied. A new technique for synthesis of GPLs based on changing magnetic field is developed. The transmission‐electron microscopy and the Raman spectroscopy were employed to characterize the size and chemical structure of the synthesized graphene platelets. The critical stress intensity factor and tensile properties of epoxy matrix filled with GPL and GNS particles were measured. Influence of filler content, filler size and dispersion state was examined. It was found that the GPLs have greater impact on both fracture toughness and tensile strength of nanocomposites compared with the GNSs. For instance, fracture toughness increased by 39% using 0.5 wt% GPLs and 16% for 0.5 wt% GNSs. 相似文献
14.
为了拓展天然纤维素材料的应用,在综合国内外对天然纤维素材料、纳米材料和抗菌材料相关研究的基础上,首先,利用LiCl/二甲基乙酰胺(DMAC)溶剂体系配置了不同共混比例的天然纤维素/聚丙烯腈纺丝液,采用静电纺丝技术制备了纤维素/聚丙烯腈纳米纤维。然后,用铜氨溶液对纳米纤维进行了抗菌处理,制备了具有一定抗菌功能的纤维集合体。最后,采用SEM观察不同共混比例下纳米纤维的微观形貌;采用TG和DSC表征其热性能;采用FTIR和表面接触角测量仪表征共混后纳米纤维的化学组成和亲水性的变化;采用振荡法测定纳米纤维的抗菌性能。结果表明:通过静电纺丝技术可制得直径在200~400nm范围内的纤维素/聚丙烯腈纳米纤维。随着纤维素含量的提高,纳米纤维的表面越来越粗糙,粘连愈加严重,且直径离散度也变大。当纤维素与聚丙烯腈的共混质量比大于75∶25时,纤维的直径标准偏差由纯聚丙烯腈纤维的100nm以下变为150nm以上。纤维素/聚丙烯腈纳米纤维具有良好的热性能,与纯纤维素纳米纤维相比热稳定性有一定提高,当纤维素与聚丙烯腈的共混质量比为25∶75时热稳定性最好。纤维素/聚丙烯腈纳米纤维的亲水性优于普通医用纱布的。经过铜氨溶液抗菌处理的纳米纤维具有良好的抗菌性能,对金黄色葡萄球菌和大肠杆菌的抑菌率分别为82%和75%。 相似文献
15.
Zhenyuan Ji Jili Wu Xiaoping Shen Hu Zhou Haitao Xi 《Journal of Materials Science》2011,46(5):1190-1195
Graphene-based nanocomposites are emerging as a new class of materials that hold promise for many applications. In this article,
we present a facile approach for the preparation of graphene/NiO nanocomposites using graphite oxide and nickel chloride as
starting materials. The as-synthesized composites were characterized using X-ray diffraction, Fourier transform-Infrared spectroscopy,
transmission electron microscopy, ultraviolet–visible spectroscopy, thermogravimetry, and differential scanning calorimetry
analyses. It was shown that graphene sheets were decorated by the in situ-formed NiO nanoparticles to form a film-like composite
structure and as a result, the restacking of the as-reduced graphene sheets was effectively prevented. The NiO-coated graphene
nanocomposites can be expected to remarkably improve the electrochemical properties of NiO and would be the promising candidates
for a variety of applications in future nanotechnology. 相似文献
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In this article, we present a surfactant-free method for the preparation of graphene/ZnS nanocomposites. The as-synthesised products were characterised by the X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy. It is shown that in the nanocomposites, individual ZnS nanoparticles are well-spread out on the graphene sheets. The good distribution of ZnS nanoparticles on graphene sheets would be promising for practical applications in future nanotechnology. 相似文献
18.
Nanocomposites of polyacrylonitrile (PAN) with reduced graphene oxide (rGO) were prepared using a solution mixing technique employing polyvinyl phenol (PVP) as a compatibilizer. The PVP can facilitate composite formation by interacting with both rGO and PAN via π-π and H-bonding respectively. Various amounts of rGO were used to prepare PAN nanocomposites. The cross-sectional morphology of the composite films shows a uniform dispersion of rGO sheets in the PAN matrix. The Fourier transform infrared (FT-IR) studies revealed that good interaction of the rGO/PVP hybrid with PAN. The wide angle x-ray diffraction (WAXS) study confirms that the rGO sheets were uniformely dispersed as individual sheets in the PAN matrix. Thermogravimetric analysis shows enhanced thermal stability of the composite compared to pure PAN. The tensile strength and elastic modulus of the nanocomposites increased with increasing rGO content. A 102% enhancement in tensile strength and a 62.9% enhancement in elastic modulus were observed in the nanocomposite with 5% rGO. 相似文献
19.
A novel intercalation nanocomposite based on polyacrylonitrile (PAN)/kaolinite was prepared by a simple in situ emulsion polymerization in the presence of organically modified layered silicates (kaolinite). The crude kaolinite (K0) was firstly modified by dimethylsulfoxide-methanol and potassium acetate-aqueous systems; acrylonitrile monomer was then intercalated into kaolinite by displacing potassium acetate from KAc-kaolinite (the kaolinite modified by KAc, marked as K2). The polymer/kaolinite composites were prepared by in situ emulsion polymerization, and characterized by means of X-ray diffraction, scanning electron microscope, transmission electron microscope and thermal gravimetric analysis. Experimental results indicate that the clay layers of kaolinite in PAN/K2 composites are well distributed and delaminated. The weight-average molecular weights were measured by small-angle X-ray scattering for all samples. The presence of clay results in an increase in molecular weights compared to pure PAN polymer due to the highly crosslinked structure. 相似文献