阳极氧化TiO2基纳米管阵列改性的研究进展

阳极氧化TiO2纳米管阵列由于具有高度有序的独特纳米结构和优异的物理化学性能,已成为纳米材料以及太阳能光转化利用等研究领域的热点之一.国内外围绕纳米管阵列的制备、改性及应用等方面开展了大量研究,取得了显著成果.最近,纳米管阵列改性方面的研究受到人们的特别关注,相关研究已经为这种高度有序纳米材料的应用打下良好基础.本文较...     

Fabrication and Visible-Light Photocatalytic Activity of AgaPO4/TiO2 Nanotube Arrays

用浸渍–沉积法将 Ag3PO4 沉积在自组装 TiO2 纳米管阵列的管壁上制备 Ag3PO4/TiO2 纳米管阵列。用 X 射线衍射、扫描电子显微镜和紫外–可见漫反射光谱对样品进行表征。通过在可见光（λ 〉 420 nm）下降解水中的罗丹明 B 检测样品的光催化活性。结果表明：由于 Ag3PO4 与 TiO2 之间形成了异质结,在 Ag3PO4 的强可见光吸收性能和该异质结的协同作用下,Ag3PO4/TiO2 异质结纳米管阵列的可见光光电催化活性高于单一的纯 Ag3PO4 和TiO2 纳米管阵列膜。     

TC4合金表面氧化钛基纳米管阵列的制备和表征

采用电化学阳极氧化法在TC4合金(Ti-6Al-4V)表面制备了TiO2基高度有序纳米管阵列。阳极氧化电解液体系为0.5wt%NH4F+0.1MH3PO4的水溶液,通过对阳极氧化电压和氧化时间的研究,揭示了纳米管阵列的制备规律。纳米管阵列的最优制备电压为20V,时间为1h,所制备纳米管管径约120nm、壁厚约17nm、管长约300nm。能量色散型X射线光谱(EDX)和X射线光电子能谱(XPS)研究结果表明没有实现对纳米结构的晶格掺杂。所制备的高度有序纳米管阵列具有广阔的应用前景。     

Ti/TiO_2/Pd纳米电极的制备和电催化性能

采用阳极氧化法在纯钛表面生成结构高度有序的二氧化钛纳米管阵列,并通过室温固相反应制备了钯纳米颗粒。采用自组装方法将钯纳米颗粒修饰到Ti/TiO2表面制备了Ti/TiO2/Pd纳米电极。利用电子扫描显微镜、X-射线衍射分析二氧化钛纳米管、钯纳米颗粒和纳米电极的微观结构和表面形貌,并研究了Ti/TiO2/Pd纳米电极对甲醇的电催化性能。结果表明,TiO2纳米管排列整齐有序,Ti/TiO2/Pd电极中Pd纳米颗粒均匀分散在TiO2纳米管表面。电化学测试结果表明,Ti/TiO2/Pd纳米电极对甲醇的电催化氧化过程具有很好的电催化活性。     

钛基TiO_2纳米管制备及其生物医用研究进展

TiO2纳米管阵列作为一种新型的纳米TiO2材料,由于具有独特的阵列结构和优异的性能,引起了人们的极大关注。详细综述了采用阳极氧化法在钛基表面制备纳米管阵列的工艺条件、形成机理,及其生物医用领域的应用研究,分析了目前存在的问题,并提出了今后研究的对策。     

TiO2纳米管阵列的制备与填充研究进展

TiO2纳米管阵列具有三雏有序纳米管状结构、大比表面积和较强的吸附能力,广泛地应用于催化材料、能源材料等领域.综述了近十年来TiO2纳米管阵列的制备方法,包括模板法,阳极氧化法等；以及纳米管内的填充技术,如电沉积法,溶液浸渍-热熔解法,化学溶液沉积法,溶胶-凝胶法,紫外光还原法等.指出采用电沉积法对TiO2纳米管进行高...     

二氧化钛纳米管阵列制备及其在染料敏化太阳能电池中的应用

以NH4F的乙二醇溶液为电解液,采用阳极氧化法在钛板上制备二氧化钛纳米管阵列,通过调控氧化电压改变纳米管的长度和管径,得到了长度为10～45μm、管径为50～150nm的二氧化钛纳米管.分析了阳极氧化实验条件对TiO2纳米管尺寸的影响,并研究了TiO2纳米管阵列的尺寸对染料敏化太阳能电池(dye-sensitized ...     

TiO_2纳米管在不同条件光催化降解的活性研究

本文利用阳极氧化法在纯钛片表面制备了TiO2纳米管阵列膜,解决TiO2光催化剂的涂敷固定问题。采用场发射扫描电镜(FESEM)和XRD对制备TiO2纳米管阵列膜的形貌和晶体结构进行表征。结果发现,所制得的纳米管管径70～80nm,壁厚5～10nm,XRD显示经420℃热处理的TiO2纳米管为锐钛矿晶型,经500℃热处理的TiO2纳米管出现金红石晶型。以10mg·L-1的甲基橙溶液为降解物进行光催化试验,分别研究了溶液的初始pH值、TiO2纳米管阵列膜的晶型、TiO2膜的使用次数对降解率的影响。试验结果表明,当溶液初始pH值为1时,TiO2纳米管阵列的光催化性能最好,同时随着TiO2膜使用次数的增加,其光催化效果有所下降。     

TiO2纳米管的制备及形成机理研究进展

TiO2纳米管具有三维有序纳米管状结构、比表面积大、吸附能力较强,在光催化、环境净化、太阳能电池、气体传感器等领域具有广泛的应用前景。主要综述了近十年来纳米管TiO2的最新研究情况,介绍了纳米管TiO2的制备方法、形成机理以及应用前景。     

温度对TiO_2纳米管光催化性能的影响

采用阳极氧化法制备TiO2纳米管阵列,对其结构进行了XRD、TEM表征,并研究了温度对TiO2纳米管光催化性能的影响及作用机理。结果表明,在40~240℃,TiO2纳米管光催化降解苯的性能随温度的升高先提高后降低,在200℃时达到最高。升高温度导致TiO2纳米管表面水分子脱附,为苯的催化降解提供了更多的反应位,这是升温提高TiO2纳米管光催化性能的主要作用机制。     

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。