利用铝阳极氧化膜电镀制备纳米材料

铝阳极氧化膜由于具有孔径分布均匀、空洞之间互相不连通、取向一致等特点,在纳米结构材料中获得广泛研究,对铝阳极氧化膜及其合成的纳米线表征,是开展铝阳极氧化膜研究的关键.首先制备了铝阳极氧化模板,随后通过电镀法制备了纳米线,并对铝阳极氧化模板和纳米线进行了表征.最后,文章对铝阳极氧化膜的研究前景进行了展望.     

功能性铝阳极氧化膜的研究与表征

铝阳极氧化膜由于具有孔径分布均匀、空洞之间互相不连通、取向一致等特点而在纳米结构材料中得到广泛研究，对铝阳极氧化膜及其合成的纳米线表征，是开展铝阳极氧化膜研究的关键。本研究制备了铝阳极氧化模板和纳米线，介绍了常用的表征方法，利用这些方法对铝阳极氧化模板进行了表征，并对铝阳极氧化膜的表征与表征方法的前景进行了展望。     

草酸中纳米孔阵列阳极氧化铝膜的一步法制备及其形貌表征

报道了用一步阳极氧化法在经过预处理的高纯铝片上制备具有纳米孔阵列结构的阳极氧化铝膜(AAM)的技术,并用扫描电子显微镜(SEM)和原子力显微镜(AFM)对样品形貌进行了表征。结果表明,高纯铝片在0~20℃、0.1~0.5 mol/L的草酸溶液中用30~60 V的直流电一步阳极氧化,再经过去铝和除阻挡层的过程,可制得纳米孔阵列阳极氧化铝膜。制得的阳极氧化铝膜中的孔,尺寸都在纳米级别,且大小均匀,相互平行排列成规整阵列,可用作制备纳米线阵列的模板。     

多孔氧化铝模板的制备及应用

以磷酸溶液为电解液、以高纯铝为阳极,采用两步阳极氧化法制备氧化铝模板。扫描电子显微镜(SEM)对其表面形貌分析表明,氧化铝膜为多孔结构,膜孔径随着阳极氧化电压的增大而不断增大。对阳极氧化电流密度变化分析证实,铝的阳极氧化经历了三个阶段:阻挡层的生成、多孔层的形成和多孔层的稳定生长。以制备的氧化铝膜为阴极、锌片为阳极,以硝酸锌和硼酸的混合液为电解液,采用交流电沉积方法制备了针状氧化锌纳米线。     

Al2O3纳米线薄膜的制备及其生成机理研究

研究了一种简单新颖的制备Al2O3纳米线薄膜的电化学方法。以阳极氧化法在高纯铝片表面制备多孔阳极氧化铝的工艺为基础,在草酸电解液中通过一次阳极氧化过程,将阳极氧化铝孔壁溶解形成Al2O3纳米线,均匀覆盖在阳极氧化铝有序孔道的上方,得到一种特殊结构的纳米线薄膜。使用扫描电镜、高分辨透射电镜和X-射线能谱仪对纳米线的形貌、结构及成分进行了表征分析。并结合扫描电镜对不同反应时间长度的产物形貌来观察纳米线的生成过程。探讨了Al2O3纳米线薄膜的生成机理。     

纳米氧化铝模板(AAO)的制备

多孔性阳极氧化铝(AAO)模板具有制备容易、成本低、孔道分布均匀等特点,是制备纳米材料的理想无机模板,近几年颇受人们的关注,获得了深入的研究。本文介绍了在草酸和磷酸溶液中,制备纳米氧化铝模板的阳极氧化工艺以及不同的电解液对模板特性的影响,并用扫描电子显微镜(SEM)对阳极氧化铝膜的形貌和结构进行了表征。     

一维阵列银纳米线制备及其微观结构

通过直流电沉积,以多孔阳极氧化铝膜(Al2O3/ Al)为模板,在纳米孔道内进行限域生长,制备了金属Ag纳米线.用X射线衍射光谱(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)等检测手段对产物进行了表征.结果表明,Ag纳米线具有面心立方晶体结构,阵列排列整齐,长度超过5μm,单体纳米线的直径约为70 nm,与所用模板的孔径相当.     

在离子液体中用阳极氧化铝模板电沉积制备稀土镧纳米线

采用二次阳极氧化法获得纳米多孔阳极氧化铝(AAO)模板,在尿素-NaB r-KB甲r-酰胺离子液体中,用AAO模板电沉积稀土镧纳米线。扫描电子显微镜(SEM)结果显示,自制AAO模板孔洞分布均匀,孔径基本一致(约60~70 nm),孔口呈六边形。经过XRD、EDS和SEM对电沉积样品的成分和形貌进行表征和分析,显示在AAO模板中有镧纳米线的存在。     

模板法交流电沉积铜纳米线阵列及其表征

先通过二次阳极氧化法制备多孔阳极氧化铝膜模板,再采用交流电沉积法将Cu金属填入模板的纳米孔洞中得到铜纳米线阵列。分别采用扫描电镜、透射电镜和X射线衍射仪对Cu纳米线阵列的形貌和晶体结构进行表征。结果表明,多孔氧化铝模板的孔洞排布致密、均匀而有序。交流电沉积所得Cu纳米线为单晶结构,直径为60~90 nm,长度为0.5~4.0μm。     

孔间距和孔径连续可调的PAA模板的制备

在磷酸溶液中以二次阳极氧化制备的多孔阳极氧化铝(PAA)模板存在孔的规整低的缺点,文中提出了在磷酸/草酸混合溶液中采用二次阳极氧化法制备高规整(PAA)模板,利用图像处理软件(Image-Pro plus)对PAA膜的扫描电镜图进行分析处理,定量研究了阳极氧化电压、草酸含量和扩孔时间对PAA模板的孔径和孔间距的影响。由实验结果可知,在质量分数1%磷酸溶液中加入0.03 mol/L草酸溶液作为阳极氧化电解液,阳极氧化电压可以达到200 V。通过调节草酸添加量和阳极氧化电压可以得到孔间距在345—498 nm范围内高规整PAA模板。通过改变扩孔时间可以获得孔径在140-400 nm范围内高规整PAA模板,并且孔径与扩孔时间呈正线性相关关系,相关系数为0.99。这种高规整孔径、孔间距连续可调的PAA模板能够被用于制备规整金属纳米线阵列、纳米管阵列和高分子纳米柱等材料。     

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。