聚噻吩敏化TiO_2复合材料的制备和光催化性能

以无水FeCl3为氧化剂,在CHCl3中采用原位氧化聚合法制备了一系列不同噻吩与TiO2摩尔比〔n(Th)/n(TiO2)〕的聚噻吩敏化TiO2(PTh/TiO2)复合材料。用TEM、FTIR、XRD、DRS和PL对复合材料进行了表征。用苯酚的光催化降解反应研究了复合材料在紫外光和太阳光下的光催化活性。结果表明,PTh的修饰减轻了复合纳米粒子之间的团聚,但对TiO2的晶体结构无影响,复合材料粒径25～30nm。PTh的敏化作用可使复合材料吸收200～800nm的光。两种光源下,复合材料的光催化活性均优于纯TiO2,当n(Th)/n(TiO2)=0.04时达最佳。紫外光下,200min时苯酚降解率达76.39%,太阳光下,120min时苯酚降解率达88.27%,较纯TiO2光催化活性分别提高了19.7%和31.53%。     

漂珠基聚吡咯敏化TiO2复合光催化剂的制备及其光催化性能的研究

本文利用溶胶-凝胶法实现了二氧化钛(TiO2)膜层在粉煤灰漂珠表面的负载,得到TiO2/漂珠复合光催化剂;采用原位聚合的方法将聚吡咯负载到TiO2/漂珠复合光催化剂上,实现材料的敏化改性,成功制备出聚吡咯-二氧化钛/漂珠(PPy-TiO2/漂珠)复合光催化材料.以亚甲基蓝(MB)为降解对象,研究了在不同吡咯(Py)与Ti投加摩尔比和不同掺杂盐酸浓度条件下制备的PPy-TiO2/漂珠复合光催化材料在可见光下的催化效果,并结合SEM、XRD、UV-vis等表征手段较为系统地研究了复合光催化剂的表面形态、晶体结构、光响应范围等.结果表明:PPy-TiO2/漂珠的光催化活性优于TiO2/漂珠,当Py/Ti摩尔比为1％,以lmol/L盐酸溶液为掺杂剂时所制备的PPy-TiO2/漂珠复合光催化剂光催化降解性能最优.     

不同酸掺杂的聚苯胺复合二氧化钛光催化剂的研究

通过水蒸汽-水解法制备了纳米级TiO2粉体,并通过原位聚合法制备了不同酸掺杂的聚苯胺(PANI)/TiO2复合材料。利用单因素实验验证了盐酸、硫酸、对甲苯磺酸和对氨基苯磺酸四种掺杂酸对TiO2光催化活性的影响。以KBF染料模拟废水为研究对象,考察了PANI/TiO2复合材料在紫外光及可见光照射下降解水中有机物的效果。结果表明,其他单因素相同时,盐酸掺杂的聚苯胺复合二氧化钛粉体效果较好。聚合反应中苯胺与过硫酸铵的摩尔比为1∶2,反应温度为5℃,反应时间4h。不同酸掺杂的聚苯胺对纳米TiO2光催化剂的改性,显著改善了纳米TiO2光催化剂在可见光条件下的光催化性能,可有效降解KBF染料。     

掺杂Tb的TiO2异质结的制备

采用溶胶-凝胶法制备了掺杂Tb的TiO2粉末,再由其制备得到TiO2/Tb-TiO2复合催化剂粉末。使用SEM手段进行了表征,在可见光照射下,对罗丹明B溶液进行脱色反应实验,以研究不同Tb掺杂量以及不同复合比例对异质结催化活性的影响。结果表明,Tb-TiO2催化剂的光催化活性比纯TiO2好;而异质结结构TiO2/Tb-TiO2复合催化剂比纯TiO2光催化性能更高,但比Tb-TiO2光催化性能略差。     

胶原纤维为模板介孔TiO_2和Pt掺杂TiO_2纤维的制备及光催化降解黑液（英文）

以胶原纤维为模板,Ti（SO4）2为钛源,合成了新型光催化剂—介孔TiO2和Pt掺杂TiO2纤维。通过场发射扫描电镜（FESEM）、比表面积和孔径分析、紫外–可见光谱和分子荧光光谱等检测手段对两种介孔TiO2纤维的结构和物理性能进行了表征。FESEM分析表明,胶原纤维的表面结构能被较好地保留在介孔TiO2和Pt掺杂TiO2纤维中。N2吸附–脱附等温线为IV型,表明TiO2和Pt掺杂TiO2纤维具有介孔结构。基于结构的特点,在可见光和UV-A激发下,介孔TiO2和Pt掺杂TiO2纤维表现出强于商品级纳米TiO2（Degussa P25）的总有机碳（TOC）脱除率。此外,Pt的掺杂能明显改善介孔TiO2的光催化活性。光催化实验表明,Pt掺杂TiO2纤维（1.0g L–1）在可见光照射420 min后,黑液的TOC脱除率为37%;UV-A（360 nm）照射300min后,TOC脱除率为51%。因此,制备的介孔TiO2和Pt掺杂TiO2纤维作为一类性能优异的光催化剂,能用于黑液的光催化降解,并在其他类似的反应条件下具有潜在的应用前景。     

基于表面等离子体共振效应的Ag(Au)/半导体纳米复合光催化剂的研究进展

由具有表面等离子体共振(surface plasmon resonance,SPR)效应的贵金属(Ag、Au等)纳米粒子和半导体纳米结构组成的纳米复合光催化剂具有优异的可见光光催化活性,成为新型光催化材料的研究热点之一。本文综述了Ag(Au)/半导体纳米复合光催化剂的制备方法、基本性质以及光催化应用方面的一些重要研究进展;重点介绍了Ag(Au)等纳米粒子的表面等离子共振增强可见光催化活性的机理,以及Ag(Au)纳米粒子与不同类型半导体复合的光催化剂的光催化性能,其中所涉及的半导体包括金属氧化物、硫化物和其他一些半导体;本领域未来几年的研究热点将集中于新型高效的Ag(Au)/半导体纳米复合光催化剂的微结构调控及其用于可见光驱动有机反应的机理研究。本文为基于SPR效应构建Ag(Au)/半导体纳米复合光催化剂的研究提供了有力的参考依据,并且指出Ag(Au)/半导体纳米复合光催化剂的研究是发展可见光高效光催化剂的重要方向。     

金属掺杂二氧化钛的研究进展

二氧化钛(TiO2)是一种比较理想的光催化剂,具有无毒、生产成本低、耐光照等特点。但是较宽的禁带使其应用受到一定的限制,通过掺杂可以改变禁带的宽度提高TiO2的光催化和光电性能。掺杂可分为非金属掺杂和金属掺杂,非金属掺杂一般是拓展其光吸收范围,提高对可见光的响应能力。金属掺杂为了抑制电子—空穴的复合,提高光催化性能,此外TiO2掺杂金属后表现出光、电、磁性能。     

铽与电气石比对Tb/电气石/TiO_2纳米管的形貌及光学性能的影响

采用溶胶凝胶法与水热法相结合的方法成功制备了Tb/电气石/TiO_2纳米管,采用SEM、TEM、XRD、XPS等研究m(Tb)/m(T)质量比对合成Tb/电气石/TiO_2粉体的形貌和光学性能的影响。实验结果表明,不同的m(Tb)/m(T)比对水热法合成Tb/电气石/TiO_2有很大影响;当掺杂量为1∶2时,Tb/电气石/TiO_2纳米管的为中空管状结构,且结构完整,形貌整齐。水热处理后生成的复合纳米管样品具有更好的光催化活性,晶型以锐钛矿型为主,结晶质量与结晶程度都有所提升,同时在TiO_2表面形成了稳定的Ti-O-Si化学键;稀土Tb的掺杂拓宽了TiO_2的光响应范围;电气石的掺杂有助于提升TiO_2的光催化性能,最佳的掺杂质量比为1∶2,掺杂过多的电气石后光催化效率却有所下降,可能是由于电气石在TiO_2表面覆盖过多导致。     

TiO_2@酵母菌草莓结构型光催化剂的合成及其催化性能

调节水相悬浮液的pH值,使得酵母菌主体粒子和P25-TiO2客体粒子表面带相反电荷,通过静电自组装法一步合成了草莓结构的TiO2@酵母菌复合光催化剂。FESEM,EDS,FT-IR,XRD,UV-VIS表征了催化剂的物化结构。FESEM结果表明产品具有椭球形态,长度为(3.6±0.50)μm,宽度为(2.4±0.45)μm,分散性好。X射线粉末衍射表明TiO2客体粒子为锐钛矿和金红石矿晶型。紫外-可见光漫反射光谱证实催化剂对紫外光具有光响应。FT-IR分析表明TiO2@酵母草莓结构的形成与酵母细胞表面和TiO2粒子的表面化学官能团有关,其形成机理可概括为静电自组装过程。沉降性能测试表明该复合催化剂具有较好的悬浮性能,这有利于催化剂的分离回收。在光催化降解刚果红染料水溶液中,TiO2@酵母光催化剂表现出了较高的光催化活性。     

V掺杂TiO_2的制备及其可见光催化性能研究

本文采用水热法制备V掺杂TiO2(V-TiO2)光催化剂,借助XRD、XPS、UV-Vis DRS等手段对V-TiO2的结构进行表征,并以酸性红染料作为模型污染物,评价V-TiO2在可见光作用下的光催化性能。实验结果表明,V离子进入TiO2晶格并取代Ti4+离子,V离子掺杂在TiO2的导带下方引入了V3d掺杂能级,V-TiO2在可见光区具有显著吸收,且光生载流子的复合受到有效抑制,因此,V掺杂明显提高了TiO2降解酸性红染料的效率。     

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。