石墨烯载钴材料的制备

本实验以150μm鳞片状石墨为原料,采用Hummers法制备氧化石墨,经超声波振荡得到氧化石墨烯,加入水合肼回流制得石墨烯材料.氧化石墨烯与CoSO4溶液混合,采用功能离子预吸附的方式,将金属离子有效地分散在氧化石墨烯载体上,原位还原金属颗粒和石墨烯,制备石墨烯载钴材料.     

石墨烯/TiO2复合材料的制备及其光催化性能的研究

本实验以细鳞片石墨为原料,采用Hummers法制备氧化石墨,经超声波振荡得到氧化石墨烯,加入水合肼回流制得石墨烯材料。采用溶胶-凝胶法制备锐钛矿型TiO2及石墨烯/TiO2复合材料。在紫外光照射下,分别以石墨烯/TiO2复合材料及锐钛矿型TiO2为催化剂,在甲基橙溶液中进行光催化降解,结果显示,石墨烯/TiO2光催化性能明显高于相同条件下的锐钛矿型TiO2。     

覆银石墨烯改性不饱和聚酯树脂导电性能研究

由鳞片状天然石墨通过改性Hummers法制备了氧化石墨,随后在硼氢化钠和硝酸银存在制得覆银石墨烯(Ag-G)。将Ag-G作为导电纳米填料添加到不饱和聚酯树脂中制备了复合材料。采用透射电子显微镜,拉曼光谱分析仪,X射线能谱仪及X射线衍射分析对Ag-G进行了表征,并对其复合材料的电性能及拉伸性能进行了测试。结果表明,银以单质的形态成功地覆载在石墨烯表面,银粒子大小为5~10 nm。随着Ag-G的用量增加,复合材料的导电性和拉伸性能呈增长趋势,Ag-G添加质量分数为25%时,材料导电性能最好,体积电阻率达0.437S/cm,拉伸性能提高了26%。     

石墨烯负载纳米银的制备及其对H2O2的电化学检测

采用改进的Hummers法制备了氧化石墨烯（GO）,然后以水合肼作为还原剂,并控制反应的pH=10来制备还原氧化石墨烯（RGO）。采用化学还原法,以石墨烯为载体,以乙酰丙酮银为前体,以硼氢化锂四氢呋喃溶液为还原剂将银离子还原,制备了石墨烯负载纳米银复合材料。通过X 射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）和透射电子显微镜（TEM）等表征方法证明了石墨烯上负载的银纳米颗粒结晶良好、尺寸均一、分布均匀,其中银纳米颗粒直径约为8nm。通过循环伏安和计时电流技术对石墨烯负载纳米银复合材料进行电化学测试,结果表明,石墨烯负载纳米银复合材料对过氧化氢的还原具有良好的电催化活性。以此复合纳米结构构建的过氧化氢传感器测试过氧化氢浓度的线性范围为0.1～62.3mmol/L（R=0.990）,检出限为0.017mmol/L（S/N=3）,响应时间小于2s。     

新型石墨烯/聚苯胺/银基复合材料的制备

通过对石墨烯(GN)制备、结构改性及与聚苯胺(PANI)、银粒子(Ag)的复合,设计了制备GN/PANI/Ag新型电极复合材料的工艺路线。首先利用Hummers氧化还原法将石墨氧化成氧化石墨烯,利用硼氢化钠将氧化石墨烯还原成石墨烯,将石墨烯与聚苯胺、银粒子反应,最后制得了GN/PANI/Ag复合材料。利用扫描电子显微镜(SEM),透射电子显微镜(TEM),热重分析(TG)和电导率测试对GN和GN/PANI/Ag的形貌,热稳定性和电化学性能进行了分析研究。结果表明,聚苯胺类衍生物、石墨烯以及银粒子三相在整个复合材料中共存,材料的复合使体系热稳定性和电化学性能得到提高。     

氧化石墨烯/聚氨酯复合材料的制备及性能研究

采用溶液共混浇注成膜法制备氧化石墨烯/热塑性聚氨酯(TPU)复合材料,并对其结构和性能进行研究。结果表明:氧化石墨烯在TPU基体材料中分散较好;随着氧化石墨烯用量(0～5份)的增大,氧化石墨烯/TPU复合材料的拉伸强度增大,拉断伸长率未明显下降;当相同用量(均为1份)的氧化石墨烯、碳纳米管、石墨和炭黑分别填充TPU时,氧化石墨烯/TPU复合材料物理性能提高幅度最大,补强性能最好。     

石墨烯纳米复合材料的制备及性能研究

以泡沫镍为模板、石墨为催化剂、酚醛树脂为碳源,采用水热法以及热处理方法制备了三维石墨烯复合材料,再利用化学沉积法制备三维氧化镍-石墨烯-泡沫镍复合材料,并对其结构和电性能进行了分析,研究结果表明,该复合材料的石墨化程度高,具备电极特性,电化学性能稳定。     

干燥方法对石墨烯在氧还原反应中活性的影响

氧化还原法制备石墨烯是已规模化的生产方法之一,制备过程中需通过干燥得到石墨烯,因此不同干燥方法对石墨烯在氧还原反应中活性的影响有所不同。以石墨为原料,通过改进的Hummers法得到氧化石墨烯(GO)溶液,再将GO溶液分别通过真空烘干干燥和真空冷冻干燥后经高温还原制备石墨烯。采用扫描电镜(SEM)、X-射线衍射(XRD)、BET比表面积测试和三电极系统电化学性能测试,比较了两种干燥方法对石墨烯的形貌、物相结构、比表面积、电化学性能及在氧还原反应中的催化活性的影响,采用Koutecky-Levich法探讨了两种干燥方法制备的石墨烯在氧还原反应中的催化机理。结果表明,相比于真空烘干干燥,真空冷冻干燥制得的石墨烯,石墨片层剥离效果优异,呈薄纱状结构,石墨化程度更高,比表面积更大。在氧还原反应中,真空冷冻干燥制得的石墨烯具有更正的起始电位、更大的极限电流密度和更高的氧还原反应催化活性,氧还原反应更接近四电子转移机制。     

银@石墨烯纳米复合材料的绿色制备及其抑菌性能

以聚乙二醇为还原剂通过水热反应,还原氧化石墨烯同时在石墨烯表面原位生长银纳米粒子,制备银@石墨烯纳米复合材料。采用紫外-可见吸收光谱、X射线衍射、红外吸收光谱、透射电子显微镜对所制备的银@石墨烯纳米复合材料进行了表征。结果表明：银以单质形态成功负载在石墨烯表面,银纳米粒子的平均粒径为30nm。以大肠杆菌为模型对纳米复合材料的抑菌性能进行测试,银@石墨烯纳米复合材料在100µg/mL时可以完全抑制大肠杆菌的生长,是一种效果显著的新型抑菌材料。     

UV固化型载银石墨烯/WPUA抗菌乳液的制备与表征

通过原位聚合法,在吸附银离子的异氰酸酯功能化石墨烯表面引入双键,再与制得的聚氨酯-丙烯酸酯进行掺杂,紫外固化后制备出载银石墨烯/聚氨酯-丙烯酸酯(IGAH/WPUA)乳液。采用FTIR、XPS、XRD、TEM、SEM、抗菌性能、机械性能和电化学等测试手段对复合物的结构和性能进行表征,探究了IGAH质量分数和光照时间对复合材料各项性能的影响。结果表明,当载银石墨烯(IGAH)质量分数(占WPUA质量,下同)为2%时各项性能趋于稳定,水洗144h后对大肠杆菌和金黄色葡萄球菌的抗菌率仍能分别达到99.9%和99.5%;体积电阻率为1.16×10~7Ω·cm,表面电阻为3.75×10~8Ω,复合材料具有优良的抗静电性;T10%从纯WPUA的296.51℃升高到308.50℃。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.