氧化石墨烯纳米带杂化粒子和石墨烯纳米带的研究进展

氧化石墨烯纳米带杂化粒子是将氧化石墨烯纳米带(GONRs)与其他纳米粒子经π-π键、氢键等结合方式复合在一起,通过这种特殊的结合形态一方面可以有效地防止GONRs的聚积,另一方面新的纳米粒子的引入能够赋予该杂化材料某些特殊的性能,从而有利于充分发挥GONRs杂化材料在聚合物改性等领域的综合性能。本文综述了氧化石墨烯纳米带杂化粒子的制备方法、性能和应用现状。此外,针对GONRs的还原产物石墨烯纳米带(GNRs)的结构、性能、制备方法及其应用领域也进行了系统性地论述。相关研究表明,氧化石墨烯纳米带杂化粒子的设计与制备是氧化石墨烯纳米带迈向实用领域的一个有效途径,而石墨烯纳米作为石墨烯的一种特殊结构的二维变体,继承了石墨烯优良的导电和导热等性能,同时特殊的边缘效应,因而呈现出了更广阔的应用潜力。     

氧化石墨烯表面稀土改性机理

石墨烯独特的物理、化学和力学性能为复合材料的开发奠定了重要基础,是各种复合材料的理想增强体,但石墨烯分散性和湿润性差的问题严重限制了其在复合材料中的进一步应用。采用浸润法和加热改性剂法制备了稀土改性氧化石墨烯(RE-M-GO),利用X射线衍射(XRD)和扫描电子显微镜(SEM),能谱仪(EDS)对RE-M-GO的形貌和相结构进行表征;并结合傅里叶变换红外(FTIR)和紫外光谱仪器(UV),分析改性氧化石墨烯的官能团结构的变化,探讨其改性机理。结果表明:稀土改性的氧化石墨烯的分散性有明显的改善,主要是由于稀土元素与氧化石墨烯的含氧官能团进行反应形成配位键,生成了新的官能团,降低了氧化石墨烯的界面能及表面能,从而改善了氧化石墨烯的分散性。     

氧化石墨烯的表面羧基化与表征

采用丁二酸酰基过氧化物对氧化石墨烯(GO)进行表面羧基化,制得羧基化氧化石墨烯(GO—COOH),利用红外光谱、X射线电子能谱、热失重等手段对产物进行了表征,并对GO和GO—COOH在水中和甲苯中的分散性能进行观察。研究结果表明:丁二酸酰基过氧化物受热分解产生的端羧基自由基以共价键的方式接枝到GO表面;与GO相比,GO—COOH在水中的分散稳定性更好,而在甲苯中的分散稳定性变差,这一现象说明GO—COOH较GO引入了更多的极性基团。本方法为GO表面增加更多的活性点提供了一条新途径。     

甲苯二异氰酸酯插层改性氧化石墨烯

采用Hummers法制备了氧化石墨,将过量的甲苯二异氰酸酯(TDI)加入到氧化石墨的N,N-二甲基甲酰胺(DMF)溶液中反应,采用X射线衍射(XRD)、红外光谱(FT-IR)、透射电镜(TEM)等对最终产物进行表征。结果表明:该法制备的功能化氧化石墨烯(TDI-GO)表面含有苯环和异氰酸酯(-NCO)基团;由于TDI的插层作用使得GO在12°左右的结晶衍射峰完全消失。将上述TDI-GO分散在不同的溶剂中,发现其在有机溶剂如N,N-二甲基酰胺(DMF)、丙酮(MEK)、二氯甲烷(DCM)中均具有较好的分散性能,不能分散于水中;由于表面含有活性的-NCO基团,该功能化氧化石墨烯可用于制备含其它功能基团石墨烯的载体,也可用于制备石墨烯与聚合物之间有化学键连接的功能性复合材料。     

氧化石墨烯制备石墨烯的研究进展

近年来,石墨烯已成为世界各国学者研究的热点。由石墨粉先制备氧化石墨烯进而制备石墨烯成为了石墨烯最重要的制备方法。本文综述了氧化石墨烯制备石墨烯的主要方法:化学法、热法、微波法、电化学法、水热法、碱法等,并对各方法的优缺点进行了阐述,最后对石墨烯的未来进行了展望。     

氧化石墨烯负载阿莫西林的研究

主要研究了氧化石墨烯(GO)对阿莫西林(AML)的负载情况。通过超声、振荡、离心和干燥等手段来制备GO-AML复合物,采用傅里叶变换红外光谱和紫外-可见分光光谱等手段对GO-AML复合物进行结构表征。还对不同pH的缓冲溶液中GO对AML的负载情况进行了控释研究。结果表明:GO与阿莫西林以氢键方式结合;在中性条件下负载量大,且在酸性条件下实行效果好。     

氧化石墨烯复合材料的研究进展

氧化石墨烯是一种性能优异的新型碳材料,具有较高的比表面积和表面丰富的官能团.简单介绍了氧化石墨烯的制备方法,重点阐述了氧化石墨烯复合材料的研究进展,包括聚合物类复合材料以及无机物类复合材料的合成方法、性能以及应用领域,展望了氧化石墨烯的制备及其复合材料今后的研究方向,提出少引入或者不引入杂离子的新型绿色环保的制备方法是氧化石墨烯制备的发展方向,氧化石墨烯的表面改性成为另一个研究重点.     

生物材料的离子束表面改性

随着表面处理技术的发展,国内我对如何改善现有的生物材料表面的各种性能,如耐蚀性,耐磨性,生物相容性等进行了研究。各种表面处理的方法受到高度重视,其中离子束表面改性技术,由于其对材料本体无负效应,已被证明是最为成功的一种。本文在综述离子束改性技术在生物材料及器械方面应用的同时,提出将梯度功能材料的新概念与离子束改性技术相结合,用以制备表面性能优异的仿生生物材料。     

氧化石墨烯改性聚硫密封胶

采用Hummers法制备了氧化石墨烯(GO)。X射线衍射(XRD)、红外光谱和拉曼光谱等表征结果表明,产物成分较纯且含有较多的活性基团;将其超声分散在邻苯二甲酸丁苄酯中,采用拉伸和粘接性能测试研究其对聚硫胶力学性能的影响。结果表明,随氧化石墨烯含量增加,拉伸强度和粘接强度先增后减;加入0.2 phr氧化石墨烯增强效果最为显著,拉伸强度由1.71MPa提高到2.12MPa,粘接强度由1.06MPa提高到1.29MPa,断裂伸长率变化较小。     

KH550表面改性氧化石墨烯/酚醛树脂复合材料的力学性能和摩擦性能

采用Hummers法对天然鳞片石墨进行氧化处理和超声剥离制备氧化石墨烯,通过γ-氨丙基三乙氧基硅烷(KH550)与氧化石墨烯(GOs)反应得到改性氧化石墨烯(MGOs)。采用模压成型方法制备MGOs/酚醛树脂(PF)复合材料。利用热重分析(TGA)、红外光谱(FT-IR)和X射线光电子能谱(XPS)分析其表面改性效果,研究不同MGOs含量的MGOs/PF复合材料的力学性能、摩擦性能,利用扫描电镜(SEM)观察复合材料磨损面的形貌。结果表明,GOs经KH550改性后彼此间形成共价键连接,MGOs的热稳定性显著提高;MGOs的加入能有效提高复合材料的力学性能和摩擦性能;其中,MGOs/PF复合材料的冲击强度提高了45.5%,弯曲强度和弯曲模量分别提高了36.7%、26.7%。     

原子转移自由基聚合反应改性氧化石墨烯研究进展

原子转移自由基聚合(ATRP)是一种具有潜在应用价值的可控活性自由基聚合方法,通过ATRP反应对氧化石墨烯(GO)进行改性,可以有效控制各种接枝聚合物分子链的长度和接枝密度,赋予GO不同的功能性,如良好的溶剂分散性、环境敏感刺激响应性、生物相容性等。文中分别从GO表面固定引发剂直接引发ATRP反应和GO表面非共价键结合ATRP聚合物分子链2种途径,对ATRP反应改性GO进行综述,总结了ATRP改性反应的过程条件和研究方法,并指出了GO功能化复合材料的功能特性和应用前景。     

Surface Energy Engineering in the Solvothermal Deoxidation of Graphene Oxide

A route to achieving high yields of monodisperse, deeply deoxidized graphene oxide (GO) in solution is presented. It overcomes many of the problems of dispersibility and inefficient reduction of GO in solvothermal deoxidation that are usually observed, despite the previous use of strong reducing agents (e.g. Fe²⁺, S or hydrazine). It is shown that the incomplete deoxidation is most likely due to agglomeration/self‐assembly of partially reduced GO, which also creates poor dispersibility. GO deoxidation is found to be highly sensitive to the solvent surface energy and, through experiments and empirical calculations, tuning the solvent surface energy to around 85.6 mJ/m² (at 100 °C) leads to fully deoxidized GO. These calculations also allow appropriate solvent surface energies to be calculated for other temperatures for deep deoxidation of GO. This approach makes solvothermal deoxidation of GO a potential route to large scale, economic production of highly disperse monolayered graphene.     

From Graphite to Graphene Oxide and Graphene Oxide Quantum Dots

Many methods have been reported for synthesizing graphene oxide (GO) and graphene oxide quantum dots (GOQDs) where a tedious operational procedure and long reaction time are generally required. Herein, a facile one‐pot solvothermal method that allows selective synthesis of pure GO and pure GOQDs, respectively is demonstrated. What is more, the final product of either GO or differently sized GOQDs can be easily controlled by adjusting the reaction temperatures or reactant ratios, which is also feasible when enlarged to gram scale. The 2.5 nm GOQDs show excellent photoluminescence that can be utilized for bioimaging or distinctive detection of Eu³⁺ and Tb³⁺ from their respective mixtures with other rare earth and/or transition metal ions, at sub‐ppm level.     

Graphene Oxide Quantum Dots Exfoliated From Carbon Fibers by Microwave Irradiation: Two Photoluminescence Centers and Self‐Assembly Behavior

Graphene oxide quantum dots (GOQDs) attract great attention for their unique properties and promising application potential. The difficulty in the formation of a confined structure, and the numerous and diverse oxygen‐containing functional groups results in a low emission yield to GOQDs. Here, GOQDs with a size of about 5 nm, exfoliated from carbon fibers by microwave irradiation, are detected and analyzed. The exfoliated GOQDs are deeply oxidized and induce large numbers of epoxy groups and ether bonds, but only a small amount of carbonyl groups and hydroxyl groups. The subdomains of sp² clusters, involving epoxy groups and ether bonds, are responsible for the two strong photoluminescence emissions of GOQDs under different excitation wavelengths. Moreover, GOQDs tend to self‐assemble at the edges of their planes to form self‐assembly films (SAFs) with the evaporation of water. SAFs can further assemble into different 3D patterns with unique microstructures such as sponge bulk, sponge ball, microsheet, sisal, and schistose coral, which are what applications such as supercapacitors, cells, catalysts, and electrochemical sensors need. This method for preparation of GOQDs is easy, quick, and environmentally friendly, and this work may open up new research interests about GOQDs.     

A Review of Recent Applications of Ion Beam Techniques on Nanomaterial Surface Modification: Design of Nanostructures and Energy Harvesting

Nanomaterials have gained plenty of research interest because of their excellent performance, which is derived from their small size and special structure. In practical applications, to acquire nanomaterials with high performance, many methods have been used to modulate the structure and components of materials. To date, ion beam techniques have extensively been applied for modulating the performance of various nanomaterials. Energetic ion beams can modulate the surface morphology and chemical components of nanomaterials. In addition, ion beam techniques have also been used to fabricate nanomaterials, including 2D materials, nanoparticles, and nanowires. Compared with conventional methods, ion beam techniques, including ion implantation, ion irradiation, and focused ion beam, are all pure physical processes; these processes do not introduce any impurities into the target materials. In addition, ion beam techniques exhibit high controllability and repeatability. Here, recent progress in ion beam techniques for nanomaterial surface modification is systematically summarized and existing challenges and potential solutions are presented.     

L-半胱氨酸还原氧化石墨烯的研究

采用改进Hummers法合成氧化石墨,在水中超声分散获得氧化石墨烯水溶胶,并加入L-半胱氨酸于95℃进行回流反应后得到还原氧化石墨烯。采用X射线衍射仪、傅里叶变换红外光谱仪和热重-差热扫描仪等探讨氧化石墨烯还原前后的结构与性能变化。结果表明,L-半胱氨酸能有效还原氧化石墨烯,且还原后的氧化石墨烯在乙醇中有较好的分散性,其所制薄膜的导电率为500S/m。由此法制备的石墨烯有望广泛应用于电子、光电、电容器和传感器等器件中。     

微波辐照气相法合成氮掺杂石墨烯

以天然鳞片石墨为原料, 采用Staudenmaier法先制备出石墨氧化物, 再经饱和碳酸铵溶液浸渍后生成NH₄⁺插层石墨氧化物. 在微波照射下, NH₄⁺分解生成的NH₃与剥离的石墨烯氧化物反应原位合成出氮掺杂石墨烯. 通过SEM、TEM、EDS、XRD、XPS和Raman测试手段对氮掺杂石墨烯进行了表征. 结果表明, 所合成的氮掺杂石墨烯呈透明绢丝状结构, 每个石墨烯片含有2~5层石墨层; 氮元素含量为1.56wt%, 其中N元素是以pyridinc N、 pyrrolic N和graphitic N形式掺入石墨层网格中.