石墨烯量子点的制备方法及应用进展

石墨烯量子点(GQDs)作为石墨烯家族中的最新一员,不仅具有石墨烯优异的特性,同时还具备量子点的特殊结构特征如量子限域效应、边缘效应和量子隧道效应等。GQDs表现出很多新颖的特性,引起了越来越多的科研工作者的关注。本文综述了近年来GQDs的主要制备方法以及在相关领域的研究进展,并对GQDs的应用前景进行了展望。     

石墨烯量子点的制备、表征与应用研究

将天然鳞片石墨氧化后用水合肼还原,再利用电化学扫描法,制备出发绿色荧光的接近于球形,直径为3~5 nm的石墨烯量子点(GQDs)水溶液。通过透射电子显微镜(TEM)对所制备的GQDs进行形貌表征,GQDs的粒子大小均一,为单层石墨烯。通过紫外可见吸收光谱(UV-vis)、荧光光谱(PL)、傅里叶变换红外光谱(FTIR)对所制备的GQDs进行性质测定,发现GQDs可以发出强烈的绿色荧光,毒性低、具有良好的水溶性、荧光稳定性和生物兼容性,并通过荧光成像证实,GQDs可以通过细胞膜顺利进入细胞内。因此,细胞发出优异的荧光表明,合成的GQDs可在细胞标记与成像等方面具有广泛的应用前景。     

石墨烯量子点的制备及应用

石墨烯量子点(GQDs)作为石墨烯家族的最新一员,除了继承石墨烯的优异性能,还因量子限制效应和边界效应而显现出一系列新的特性,引起了化学、物理、材料和生物等各领域科研工作者的广泛关注。GQDs的制备方法通常分自上而下和自下而上的方法。对其各种制备方法和应用分别进行了介绍,并结合各种应用对GQDs的要求给出了制备方法的建议。指出了GQDs研究中存在的问题及发展方向。     

石墨烯量子点与纤维素构筑的蓝色发光水凝胶研究

以氢氧化钠/尿素为溶剂溶解微晶纤维素,在溶解过程中原位引入高量子产率的蓝光石墨烯量子点(GQDs),制备了GQDs/纤维素发光水凝胶。我们发现交联剂的用量增加,复合水凝胶的力学强度增大,透光率减小,溶胀率减小,GQDs释放速率减小,但是光谱仍保持稳定。Fe3+对GQDs/纤维素水凝胶具有荧光猝灭特性。我们相信,这种基于天然生物资源的发光水凝胶为化学和生物传感器的设计提供了低成本、多样化、环境友好的选择。     

N-掺杂石墨烯量子点的制备及荧光成像研究

以石墨烯量子点(GQDs)为碳源,三聚氰胺为氮源,采用高温热解而后硝酸氧化的方法制备N-掺杂石墨烯量子点(N-GQDs),并对其微观形貌、光学性质、细胞毒性和细胞成像性质进行表征。结果表明:N-GQDs的尺寸分布较为均匀,平均粒径为3.5 nm。在365 nm紫外灯照射下,N-GQDs呈现明显的蓝色荧光,且其量子产率为15.8%,明显高于GQDs(0.8%)。在浓度≤120μg/mL的情况下,N-GQDs对脑胶质瘤U251细胞未表现出明显毒性,可应用于U251细胞的荧光成像。     

石墨烯量子点的制备及其在生物医学领域的应用

石墨烯量子点(GQDs)作为石墨烯家族的一员,因其边界效应和量子限域效应而具备光致发光等优异的性质,同时具有良好的生物相容性及低细胞毒性,这使其在生物医学领域备受关注。综述了石墨烯量子点的制备方法,包括水热法、微波辐射法、弧光放电法及电化学法等。并结合最新的研究进展,讨论了石墨烯量子点在生物医学领域的应用,包括生物成像、生物传感及药物传递。     

含甲氧基官能团的石墨烯量子点的制备与研究

采用溶剂热的方法,在200℃的温度下反应10 h制备了石墨烯量子点;并利用透射电子显微镜、荧光光谱、红外光谱等方法分析表征样品.测试结果表明材料具有以下特点:该石墨烯量子点颗粒尺寸在1.5 ～4 nm;能够均匀的分散在水溶液中;表面含有甲氧基官能团;发射光谱随着激发光的红移而红移;并且具有上转换的发光性能.     

GQDs@Gel纳米体系的制备及其抑菌性能研究

将具有光动力性能的石墨烯量子点(GQDs)包载于可降解的水凝胶(Gel)内,形成酸度敏感型GQDs@Gel复合体系。经光学和结构性能表征,显示GQDs成功包载于Gel, Gel在弱酸性条件下可降解,使GQDs的释放具有酸度响应性。抑菌实验证实,GQDs@Gel对于大肠杆菌和金黄色葡萄球菌具有明显的抑菌效果,抑菌效果呈现明显的酸度依赖性和光敏感性。     

纳米碲化镉/石墨烯水溶液的制备及荧光性能研究

以石墨为原料,通过热还原法制备了还原性氧化石墨烯(rGO),然后采用水热法将CdTe量子点与r GO以非共价键的方式复合在一起,制备出了纳米CdTe/rGO水溶液。通过X射线衍射仪、紫外-可见分光光度计、透射电子显微镜和荧光分光光度计对样品进行了表征。结果表明,160℃下水热30 min制备的CdTe/rGO荧光性能最好。CdTe量子点均匀地负载在rGO表面;CdTe量子点的团聚体尺寸由复合前的220 nm减小到60~120 nm;并在527 nm处产生荧光猝灭,说明rGO与CdTe量子点之间存在着光诱导电子转移,从而为制备性能可靠的光伏器件提供可能。     

异丙威荧光分子印迹聚合物的制备

以石墨烯量子点(GQDs)为荧光组分,异丙威为模板分子,甲苯/石蜡混合溶剂为致孔剂,甲基丙烯酸为功能单体,三羟甲基丙烷三丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用热引发沉淀聚合法制备了对异丙威有吸附作用的异丙威荧光分子印迹聚合物。结果表明:异丙威荧光分子印迹聚合物表面凹凸不平,直径较大;其与甲基丙烯酸之间以非共价键结合;荧光分子印迹聚合物内部存在大量印迹"空洞"或"孔穴",对高温有一定的耐受性;异丙威荧光分子印迹聚合物具有良好的吸附性、荧光性、选择特异性,可为环境、食品中农药痕量残留检测提供一种新途径。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.