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本文以钛酸丁酯[Ti(OC4H9)4]、去离子水、盐酸和聚乙二醇(PEG)1000为原料,采用溶胶-凝胶法和旋转涂膜工艺,在玻璃基底上制备纳米TiO2薄膜和TiO2多孔薄膜.利用原子力显微镜(AFM)、X射线衍射仪(XRD)和紫外-可见光谱仪(UV-Vis)对薄膜进行分析表征.结果表明,实验制备的TiO2粉体为锐钛矿晶型,纳米TiO2薄膜的平均粗糙度为17.2nm,TiO2多孔薄膜平均粗糙度为1.55 nm.TiO2多孔薄膜有较高的透射性和光催化活性,可直接用于光催化降解有机物等领域. 相似文献
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纳米复合结构二氧化钛薄膜的制备及其光降解水中若丹明B的能力 总被引:3,自引:0,他引:3
用双氧水低温氧化金属钛片的方法制备了TiO2纳米棒阵列,并以该阵列为基体,用浸渍渗透溶胶-凝胶技术制备了TiO2纳米颗粒嵌入TiO2纳米棒阵列基体的复合结构薄膜.用X射线衍射、场发射扫描电镜及光致发光光谱研究制得薄膜的结构和发光性能.结果表明:纳米棒阵列为金红石与锐钛矿的混晶结构,而溶胶-凝胶获得的TiO2为纯锐钛矿结构.在复合构造薄膜中TiO2纳米颗粒嵌入到纳米棒阵列间隙中,其光生电子-空穴对的空间分离效果得到明显改善.用制得的薄膜进行光催化降解水中若丹明B的实验结果显示:复合结构薄膜的光催化效率高于相应的纳米棒阵列,其表观反应常数是相同质量的溶胶-凝胶法制备薄膜的3倍,这是因为第二相TiO2纳米颗粒嵌入TiO2纳米棒阵列中促进了光生电子-空穴对的空间分离,从而提高了复合结构薄膜的光催化活性. 相似文献
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将纳米TiO2颗粒以电泳沉积法披覆于导电玻璃上,同时整合光电极、反电极、电解质及染料制备出染料敏化太阳能电池.首先将TiO2纳米颗粒与异丙醇所混合的电泳悬浮液通过电泳技术沉积出适当厚度的多层膜结构;精确控制制程中的电流、电压与沉积时间而获得单层厚度为3.3μm的TiO2薄膜.此多层膜通过低温烧结增加其致密性及染料披覆效果.最后将此多层薄膜作为工作电极,封装成染料敏化太阳能电池,经由I-V曲线检测结果显示,所制染料敏化太阳能电池的光电转换效率为5.29%,且这种染料敏化太阳能电池的制造成本十分低廉. 相似文献
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以单分散聚苯乙烯(PS)微球为原料,水为稀释溶剂,利用垂直沉降法制备出多层PS球有序阵列模板.采用溶胶-凝胶法制备TiO2溶胶,并用胶晶模板法制备出锐钛矿型TiO2有序多孔薄膜.然后将金属银纳米晶掺入多孔膜骨架中制备出含银纳米晶的TiO2有序多孔发光薄膜.分析了掺银的TiO2有序多孔膜的形貌与结构,并研究了掺银的TiO2有序多孔膜吸附罗丹明B及量子点CdSe荧光物质的荧光增强性能.结果表明:掺银的TiO2薄膜基本呈现多孔结构并保留有一定的有序性.有序多孔骨架中银纳米晶的表面荧光增强作用可大幅度提升荧光物质的荧光性能,从而扩展了TiO2有序多孔薄膜在生物信息探测、光信息处理领域的应用. 相似文献
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采用水热合成法制备出TiO2纳米管,通过XRD、TEM和氮气等温吸附-脱附仪等测试手段对TiO2纳米管进行了表征.用烧结的TiO2纳米管和P25粉末混合制成薄膜电极,并研究了薄膜电极的表面形貌、染料吸附量和光电性能.研究表明,加入TiO2纳米管可以制备出机械稳定的薄膜;掺杂TiO2纳米管的含量越多,薄膜电极的染料吸附量越大;掺杂5%烧结纳米管粉末的薄膜电极的光电性能最好,其短路电流可达3.25mA,光电转换效率达到1.67%. 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献