氧化石墨烯的制备、结构控制与应用

石墨烯具有卓越的力学、电学、热学和阻隔性能,但疏水性、生物不相容性等缺点限制了其在诸多方面的应用。氧化石墨烯（GO）为石墨烯的衍生物,是一种新型的碳材料,边缘处具有羧酸官能团并且其表面含有羟基和环氧基团,具有良好的分散性、双亲性、生物相容性等性能,被视当代最具有发展前景的碳材料之一。本文简述了氧化石墨烯的结构模型、制备方法和官能团可控氧化石墨烯的制备,介绍了氧化石墨烯的性能和的应用进展,分析了氧化石墨烯在制备和应用方面的一些不足。最后,阐述了石墨烯未来面临的挑战以及潜在的发展前景。     

聚合物基氧化石墨烯纳米复合材料研究进展

氧化石墨烯作为石墨烯的重要衍生物,原料来源广泛,制备过程简单,成本低廉,具有优异力学性能、耐磨性能以及吸附性能等,其还原产物具有优良的导电性能和导热性能等,是聚合物基纳米复合材料的理想填料。近年来,随着复合材料制备方法的不断革新,聚合物基氧化石墨烯纳米复合材料得到了快速发展,并在储能、阻燃等领域实现了规模化应用,有助于引领聚合物基氧化石墨烯纳米复合材料相关产品的进一步开发和应用。本文系统介绍了氧化石墨烯的改性方法,综述了聚合物基氧化石墨烯纳米复合材料的研究进展,展望了聚合物基氧化石墨烯纳米复合材料的发展前景。     

氧化石墨烯纤维的制备工艺研究

石墨烯纤维是近年发展起来的一种新型碳质纤维,因其优异的电学性能、机械性能而具有良好的发展前景。本文采用Hummers法制备氧化石墨烯,并探索了氧化石墨烯通过纺丝过程制备氧化石墨烯纤维的方法。采用傅里叶红外光谱仪和扫描电镜对产物进行了表征。本文选出了成功制备氧化石墨烯纤维的凝固浴浓度和纺丝注射器内径等条件。红外结果显示制得的氧化石墨烯氧化效果良好,氧化石墨烯纤维具有一定强度和柔韧性。     

稳定氧化石墨烯陶瓷复合膜制备以及分离性能的研究

文章以氧化铝陶瓷管作为载体,利用抽真空的方法制备了氧化石墨烯陶瓷复合膜。探索了氧化石墨烯分散液的pH对所制备的氧化石墨烯陶瓷复合膜水稳定具有很大的影响,研究发现石墨烯分散液为酸性的时候,所制备的氧化石墨烯陶瓷复合膜的水稳定性最好;利用拉曼(Raman),扫描电镜(SEM)等对氧化石墨烯膜的结构及性质进行了表征。利用氧化石墨烯膜对盐进行了分离性能的测试,研究发现氧化石墨烯膜对NaCl、CaCl_2和MgSO_4的截留率分别为55%、80%和82%。     

磺化石墨烯的制备及其催化性能研究

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丰富的官能团。氧化石墨烯纳米片表面很容易进行化学修饰键合有机官能团而改变其性质。本文采用Hummers法制备氧化石墨烯,将制备的氧化石墨烯通过磺化反应制备出具有酸催化活性的磺化石墨烯固体酸催化剂,采用FT-IR、SEM和XPS等测试技术对其组成与结构进行表征。以制备的磺化石墨烯作为固体酸催化剂用于地沟油和甲醇反应制备生物柴油。通过GC-MS对反应产物组分分析及热值、黏度、酸值等指标测定,证实本实验制备的磺化石墨烯具有良好的酸催化性能。     

氧化石墨烯/环氧富锌底漆的制备及性能研究

采用分散性能优异的氧化石墨烯(GO)代替环氧富锌底漆中的部分锌粉,制备了一种氧化石墨烯/环氧富锌底漆。采用X射线衍射分析仪、透射电子显微镜、扫描电子显微镜、盐雾试验仪、耐冲击测试仪、附着力测试仪等对氧化石墨烯/环氧富锌底漆中氧化石墨烯分散效果以及氧化石墨烯/环氧富锌底漆涂层的性能进行了方法分析。结果表明,氧化石墨烯添加量为0.5%时,氧化石墨烯/环氧富锌底漆中氧化石墨烯的分散效果最好,且氧化石墨烯/环氧富锌底漆涂层具有最佳的防腐性能。     

氧化石墨烯/壳聚糖复合材料应用性能研究综述

近年来,石墨烯以其良好的导电性、导热性能、优异的力学性能以及光学性能等在众多领域得到广泛的应用。同时,石墨烯的制备也有了较大的进展。文章综述了石墨烯的化学制备方法及氧化石墨烯/壳聚糖复合材料的应用性能,并对石墨烯复合材料的应用进行了展望。     

石墨烯的氧化程度和含量对水性锌粉涂料防腐性能的影响

制备了 3种不同氧化程度的氧化石墨烯,利用氧化石墨烯对水性环氧富锌涂料进行改性。采用盐雾试验、电化学测试、耐冲击性及附着力测试等对改性涂层的性能进行研究,研究发现氧化程度较低的氧化石墨烯改性环氧富锌涂料性能最佳。然后探究了氧化石墨烯含量和锌粉含量对该涂层的耐腐蚀性和力学性能的影响。结果表明：氧化石墨烯（ GO）的添加可以有效延缓钢材的腐蚀,当 GO-1添加量为 0.36%（质量分数,下同）,锌粉含量为 44%时,制备所得的 GO-1/水性环氧富锌涂料的综合性能最佳。当制得的氧化石墨烯的氧化程度较小,含氧基团较少且没有出现羧基时,涂料的耐腐蚀性能得到改进。     

氧化石墨烯分离膜的制备及其水处理领域的应用进展

氧化石墨烯优越的物理化学性能和膜技术的广泛应用使氧化石墨烯分离膜成为解决水环境污染和水资源短缺问题最具潜力的手段之一。本文简要介绍了氧化石墨烯分离膜的概念、分类和制备方法,在氧化石墨烯分离膜的制备方法中,表面改性的氧化石墨烯膜和氧化石墨烯杂化复合膜的相关研究报道比较多;梳理了最近几年氧化石墨烯分离膜在水处理领域的应用研究,主要包括重金属的去除、脱盐、抗菌、油水分离、染料脱色以及天然有机物的去除。详细介绍了氧化石墨烯分离膜的独特分离性能和分离机理,氧化石墨烯能够改善原有聚合物膜的某些性能,比如提高水通量、污染物截留率、膜的机械强度和抗污染性等,分离机理主要为尺寸筛分机制和电荷效应。最后,展望了氧化石墨烯分离膜在水处理领域未来的发展和面临的挑战。     

Hummers法制备氧化石墨烯

石墨烯作为一种新兴碳材料,具有良好的物理和化学特性,在各个领域都具有广阔的开发前景。通过对石墨烯进行氧化,增加其表面的官能团,能帮助提升其性能。本文介绍了氧化石墨烯的常用制备方法 Hummers法,并提出了如何在制备条件上改进,以加强氧化石墨烯的性能。     

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

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.     

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.     

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。