酞菁类光敏染料的研究进展

酞菁类光敏染料具有低成本、化学性质稳定、对环境友好等优势,越来越受到人们的重视,近年来已成为研究的热点。研究人员现已对许多种酞菁类光敏染料进行了大量研究,数千种不同分子结构的该类型化合物已被合成,研究表明在取代基的作用下,与不同的金属络合所表现出的性能、特征各不相同,从而得出了一些能有效改善酞菁光谱吸收特性和提高光电转...     

4,4′,4″,4''''''''''''-四叔丁基酞菁化合物的合成及性能研究

在七十年代中期以前,酞菁化合物研究的重点主要有两个方面,一是从纺织品、印刷油墨、涂料和塑料等专用着色的角度出发研究开发一些酞菁类商品染料和颜料;二是从化学的角度出发,研究不同金属取代、不同周边取代的酞菁化合物的合成和他们的光化学、光物理性能以及分子结构、晶体结构等等。而进入七十年代中期以后,随着现代高技术的发展,出现了对功能性染料的需求,而酞菁类化合物以其独特的光化学、光物理性质及廉价、低毒的优     

桥连吸附基团对酞菁敏化太阳能电池性能的影响

染料敏化太阳能电池中,光敏剂是影响电池光伏性能的重要因素,其中酞菁类光敏剂在红光区具有优良的光吸收性能,光化学稳定性高。根据染料敏化太阳能电池的工作原理,通过扩大共轭结构和引入吸电子结构,可以有效的调节染料的能级。综述了吸附基团和桥连结构对染料光敏性能的影响,吸附基团通过共轭结构或直接连接在酞菁环上,会有效的增强电子的流动。     

金属酞菁及其取代衍生物的结构与光电性能研究进展

由于取代方式的不同,使得金属酞菁衍生物数目庞大,结构各异。晶体结构的不同,造成配合物光电性能等多种性质的改变。酞菁类光敏材料研究方法有溶剂调节法,相转移法、溶胶-凝胶法、气相沉积法和真空热蒸发等,这些技术调变了酞菁衍生物的光电导性能,在光动力疗法等领域意义重大。酞菁类气敏材料对某些气体具有选择性高、响应灵敏等特点,可用于气体传感器的制作。建议进一步探讨取代金属酞菁衍生物的光敏、气敏机理,以便在分子层次上优化设计分子的结构,改善材料性能,拓宽应用范围。     

偶氮染料的光敏性研究

合成了单偶氮蒽醌、双偶氮蒽醌和双偶氮芴酮三个系列偶氮染料,并以此制成了功能分离型双层光电导体。蒽醌类单偶氮染料扩大取代基的共轭体系,可以提高光敏值,最大可由Ix.S2800提高到Ix.S62,含-NO_2的染料光敏性最高,最低为-OCH_3。蒽醌双偶氮类染料取代基对光敏性的影响与蒽醌单偶氮类染料相同,前者的光敏性高于取代基相同的后者。取代基对芴类双偶氮染料光敏性的影响与前两类不同,含-Cl取代时光敏性最高,含-NO_2最低。染料的光敏性排序为:芴酮类>双偶氮蒽醌类>单偶氮蒽醌类。     

不对称周环取代酞菁配合物的分子结构特征

文章综合分析了迄今国内外合成的不对称周环取代酞菁配合物的研究成果,总结了不对称周环取代酞菁配合物一般具有的ABBB、AABB和ABAB三种类型的分子结构特征。不对称取代酞菁配合物所具有的这些特殊结构特征使得它们在化学、物理学、生物学上呈现出特异的性能。     

酞菁衍生物的组装改性技术及应用研究进展

酞菁及金属酞菁的改性组装可以调变其结构和特性,进而开发出多种先进的功能材料。酞菁改性的理化方法包括聚合、取代、负载等手段,技术工艺包括气相沉积法、真空镀膜法、旋涂法、电化学聚合法、相转移法、溶胶-凝胶法、LB膜技术等。除用于染料和颜料外,酞菁衍生物的应用领域主要有新型功能材料(光敏材料、气敏材料等),新型仿酶催化剂(新型脱硫催化剂、有机反应的催化剂、新型水质处理剂等)。     

酞菁分子结构特征对复合凝胶玻璃体系光限幅性能的影响

用溶胶凝胶法将2组具有不同分子结构特征的酞菁配合物分别植入二氧化硅凝胶基质,制备均匀掺杂的复合凝胶玻璃,并对其光限幅性能进行测试。研究结果表明:掺杂酞菁分子结构特征对其复合体系的光限幅性能有显著影响。掺杂无金属酞菁(phthalocyanine, H2Pc)和不同金属酞菁配合物(metallophthalocyanine, MPc)的硅氧凝胶玻璃,其光限幅效应随中心离子不同而异,并依 H相似文献   

蒽醌型负二向性液晶染料的研究——Ⅱ.染料的分子结构对其显示性能的影响

介绍了五类α-位取代的蒽醌型负二向性染料的光谱性能及其在液晶中的应用性能,这些染料的有序参数最高达0.36。探讨了染料分子结构对有序参数及溶解的影响。     

光敏染料在Gr(a)tzel型太阳能电池上的应用及其研究进展

对光敏染料在Gratzel型太阳能电池上的应用及其研究进展进行了综述.比较了天然染料、纯有机染料和金属有机配合物染料对此类电池的敏化效果,并讨论了染料的结构和性质对电池性能的影响,指出通过分子设计合成高效光敏染料可推动Gratzel型太阳能电池的发展和实用化.     

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。