共查询到18条相似文献,搜索用时 171 毫秒
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本研究采用基于密度泛函理论的第一性原理方法, 在广义梯度近似下, 分别建立了具有不同碳氧比的“铝/氧化石墨烯/铝(Al/GO/Al)”界面模型以及含缺陷“Al/GO/Al”三层界面模型。探讨了含氧官能团和单空位缺陷、双空位缺陷以及拓扑缺陷对还原氧化石墨烯增强铝基复合材料界面性质的影响。研究结果表明: 在“Al/GO/Al”界面模型中, 环氧基优于碳原子而与铝原子产生明显的电荷交互作用, 氧原子净电荷为-0.98 e, 铝原子净电荷为0.46 e, 环氧基有利于复合材料中还原氧化石墨烯与铝基体之间的界面结合。当缺陷存在时, 含缺陷的“Al/GO/Al”界面模型中缺陷处碳原子净电荷在-0.05 e至-0.38 e区间, 环氧基与碳原子之间存在较弱的相互作用, 与铝原子间相互作用明显较强。环氧基抑制了空位缺陷处碳原子与铝原子之间的反应, 可保护含空位还原氧化石墨烯中碳原子结构的完整性。本研究可为开发高性能Al/GO/Al基复合材料提供理论指导。 相似文献
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采用改进的Hummers法制备氧化石墨烯,然后将其与聚丙烯/尼龙6(PP/PA6)两组分聚合物进行熔融共混制备聚丙烯/尼龙6/氧化石墨烯纳米复合材料。通过拉伸强度测试、差示扫描量热测试并结合扫描电子显微镜对尼龙6分散相尺寸大小观察表明,由于氧化石墨烯表面环氧官能团与尼龙6中端氨基能发生化学反应,有效提高了各组分之间的界面相互作用;少量的氧化石墨烯使尼龙6分散相尺寸大幅度减小,并使复合材料拉伸强度大幅度提高,由此表明石墨烯对热力学不相容聚丙烯/尼龙6两组分聚合物具有良好的增容作用。 相似文献
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石墨烯衍生物是利用氧化石墨烯表面的含氧官能团进行化学修饰而形成的复合炭材料。在兼备石墨烯非凡的物理及化学性质基础上,石墨烯衍生物还具有优良的水溶性和生物相容性,从而拓展了石墨烯的应用领域。综述石墨烯衍生物在肿瘤治疗方面的研究进展,主要包括生物成像、纳米载药及光动力疗法,为其在生物医药领域的进一步应用提供了新方法和新思路。 相似文献
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石墨烯是一种具有单层蜂窝状二维网格结构的新型材料,具有优异的力学、化学性能。氧化石墨烯(GO)作为氧化-还原法制备石墨烯的中间体,具有较高的比表面积以及石墨烯所不具备的丰富官能团。鉴于官能团的存在,GO具有优良的化学修饰性能,以此可制备性能更高的或具备新性能的GO/聚合物复合材料。文中综述了氧化石墨烯的结构、性能及制备方法,主要介绍了制备GO的Hummers法,比较了GO/聚合物复合材料的不同制备方法,列举了复合材料的性能特点,最后对GO复合材料制备方法的发展和GO/聚合物复合材料的应用前景进行了展望。 相似文献
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目的研究氧化石墨烯含量对氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶性能的影响。方法将氧化石墨烯作为物理交联剂,改变氧化石墨烯的相对含量,制备氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶,并分析其结构、热稳定性、力学、平衡溶胀比和弹性恢复能力。结果氧化石墨烯的含氧官能团与聚乙烯醇的-OH、聚丙烯酸的-COOH以氢键结合,增加氧化石墨烯相对含量可使复合水凝胶的热稳定性和力学性能得到増强,平衡溶胀比减小。结论在试验参数范围内,制得的氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶具有优异的热稳定性、力学性能和弹性恢复能力。 相似文献
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目的总结归纳氧化石墨烯及其复合材料在抗菌纺织品类包装材料的应用现状,为氧化石墨烯及其复合材料在纺织领域的应用提供参考。方法总结氧化石墨烯的性能、结构特点以及抗菌机理,阐述氧化石墨复合材料、复合纤维材料和复合织物等纺织品类材料的抗菌性能应用,并简单讨论氧化石墨烯的抗菌影响因素和氧化石墨烯的生物安全性。结果氧化石墨烯具有二维纳米结构、优异的比表面积和水溶性,纺织品类包装材料通过与氧化石墨烯的复合应用可改善其抗菌性能。目前,氧化石墨烯抗菌性能的应用尚处于初级阶段,需要更深入的研究。结论随着对氧化石墨烯研究的不断深入,氧化石墨烯在抗菌纺织品类包装材料的应用会越来越广泛。 相似文献
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Franklin Kim Laura J. Cote Jiaxing Huang 《Advanced materials (Deerfield Beach, Fla.)》2010,22(17):1954-1958
Graphene oxide (GO) is a promising precursor for preparing graphene‐based composites and electronics applications. Like graphene, GO is essentially one‐atom thick but can be as wide as tens of micrometers, resulting in a unique type of material building block, characterized by two very different length scales. Due to this highly anisotropic structure, the collective material properties are highly dependent on how these sheets are assembled. Therefore, understanding and controlling the assembly behavior of GO has become an important subject of research. In this Research News article the surface activity of GO and how it can be employed to create two‐dimensional assemblies over large areas is discussed. 相似文献
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Huang X Yin Z Wu S Qi X He Q Zhang Q Yan Q Boey F Zhang H 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(14):1876-1902
Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed. 相似文献
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An effective carbon fiber/graphene oxide/carbon nanotubes (CF-GO-CNTs) multiscale reinforcement was prepared by co-grafting carbon nanotubes (CNTs) and graphene oxide (GO) onto the carbon fiber surface. The effects of surface modification on the properties of carbon fiber (CF) and the resulting composites was investigated systematically. The GO and CNTs were chemically grafted on the carbon fiber surface as a uniform coating, which could significantly increase the polar functional groups and surface energy of carbon fiber. In addition, the GO and CNTs co-grafted on the carbon fiber surface could improve interlaminar shear strength of the resulting composites by 48.12% and the interfacial shear strength of the resulting composites by 83.39%. The presence of GO and CNTs could significantly enhance both the area and wettability of fiber surface, leading to great increase in the mechanical properties of GO/CNTs/carbon fiber reinforced composites. 相似文献
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Wang J Wang Y He D Liu Z Wu H Wang H Zhao Y Zhang H Yang B Xu H Fu M 《Journal of nanoscience and nanotechnology》2012,12(8):6460-6466
Hydrophobic graphene-based material at the nanoscale was prepared by treatment of exfoliated graphene oxide with organic isocyanates. The lipophilic modified graphene oxide (LMGO) can then be exfoliated into the functionalized graphene nanoplatelets that can form a stable dispersion in polar aprotic solvents. AFM image shows the thickness of LMGO is approximately 1 nm. Characterization of LMGO by elemental analysis suggested that the chemical treatment results in the functionalization of the carboxyl and hydroxyl groups in GO via formation of amides and carbamate esters, respectively. The degree of GO functionalization can be controlled via either the reactivity of the isocyanate or the reaction time. Then we investigated the thermal properties of the SPFGraphene by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), the TGA curve shows a greater weight loss of approximately 20% occurred indicating removal of functional groups from the LMGO sheets and an obvious exothermic peak at 176 degrees can be observed from 150 to 250 degrees. We also compared the structure of graphene oxide with the structure of chemical treated graphene oxide by FT-IR spectroscopy. The morphology and microstructure of the LMGO nanosheets were also characterized by SEM and XRD. Graphene can be used to fabricate a wide range of simple electronic devices such as field-effect transistors, resonators, quantum dots and some other extensive industrial manufacture such as super capacitor, li ion battery, solar cells and even transparent electrodes in device applications. 相似文献
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Heo S Cho SY Kim do H Choi Y Park HH Jin HJ 《Journal of nanoscience and nanotechnology》2012,12(7):5990-5994
Graphene, a single layer of carbon atoms in a two-dimensional lattice, has attracted considerable attention owing to its unique physical, chemical and mechanical properties. In particular, because of its excellent thermal properties such as high thermal conductivity and good thermal stability, graphene has been regarded as a one of the promising candidates for the reinforcing fillers on the polymer composites field. In this study, we prepared the poly(methyl methacrylate) (PMMA)/graphene oxide (GO) nanocomposite by a simple solution mixing process, and examined the thermal reinforcing effects of GO on a PMMA matrix. Using thermogravimetric analysis, differential scanning calorimeter, and thermal conductivity meter, we investigated the effects of GO on the thermal properties of PMMA/GO nanocomposites. With 3 wt% of GO loading, the glass transition temperature (Tg) of the PMMA/GO nanocomposite were increased by more than 7 degrees C and the thermal conductivity of which also improved 1.8 times compared to pure PMMA. 相似文献
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Graphene is a two-dimensional carbon based material. Remarkable mechanical, thermal and electrical properties of graphene make it as promising material for advanced applications; nevertheless, majority of its mechanical properties are still unknown. This research investigates buckling and bending behaviors of monolayer and multilayer armchair and zigzag graphene sheets. Bending stiffness, critical buckling force per unit length and critical strain of graphene sheets have been measured by molecular dynamic simulation method. Zigzag graphene sheet shows higher bending stiffness than armchair sheet. Van der Waals interaction between graphene sheets has an improving effect on the stability of middle layers. Cross-linkages reduce the buckling force per unit length and the buckling strain of multi layer graphene sheets. 相似文献
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Marques PA Gonçalves G Singh MK Grácio J 《Journal of nanoscience and nanotechnology》2012,12(8):6686-6692
Graphene and its derivatives have attracted great research interest for their potential applications in electronics, energy, materials and biomedical areas. When incorporated appropriately, these atomically thin carbon sheets are expected to improve physical properties of host polymers at extremely small loading. Herein, we report a novel two-step method for the preparation of PLLA/Hap/graphene oxide nanocomposites with augmented mechanical properties when compared to PLLA/Hap and neat PLLA. The presence of graphene oxide (GO) had a positive effect on the dispersion of hydroxyapatite particles on the polymeric matrix contributing for a good homogeneity of the final nanocomposite. PLLA nanocomposites prepared with 30% (w/w) of Hap and 1% (w/w) of GO showed the highest hardness and storage modulus values indicating an efficient load transfer between the fillers and the PLLA matrix. These materials may find interesting biomedical applications as for example bone screws. The following step on the study of these materials will be in vitro tests to access the biocompatibility of these new nanocomposites. 相似文献