电气石/TiO_2复合光催化材料在实验室废水处理中应用

纳米TiO_2光电催化技术是有效提高光催化反应效率的重要途径之一。电气石/TiO_2复合光催化材料体系中,电气石微粒天然电场能够有效降低光生电子(e-)和光生空穴(h’)之间的再复合反应率,电气石微粒辐射的远红外线能够降低水分子团中水分子数目,电场和红外线协同促进生成羟基自由基.OH。以电气石/TiO_2复合光催化材料为核心的实验室废水自动处理装置,对甲基橙的去除率为99.1%、Cu~(2+)去除率为99.5%、Cd~(2+)浓度为去除率为99.9%、Pb~(2+)浓度为去除率为99.9%。     

氢化黑二氧化钛-电气石复合可见光催化材料的制备及性能

为提高纳米Ti O₂在可见光区的催化效率，以天然电气石、钛酸丁酯等为原料，应用溶胶-凝胶技术制备了纳米Ti O₂-电气石复合光催化材料(T-T)，然后通过高温氢化还原黑化法，制备了氢化黑T-T复合可见光催化材料。研究表明，氢化黑T-T复合可见光催化材料受到扫描电镜(SEM)的电子束轰击后能够捕获电子而发亮，保持了黑色电气石的天然电场特性，同时微观表面不平整，呈现阶梯层次状，且分布着不均匀的纳米孔。在模拟太阳光下的甲基橙催化降解实验中，以550°C氢化4 h所制得的氢化黑T-T复合可见光催化材料对甲基橙的光催化降解率可达到99.8%，反应体系的溶解氧含量峰值可达到8.017 mg/L。氢化黑T-T复合可见光催化材料在电气石天然电场的作用下，其光催化能力优于常规氢化黑TiO₂。     

ZrO2-CNB复合光催化剂的制备及其性能研究

以四苯基硼化钠和尿素作为原料，通过热聚合法，利用热诱导前驱体发生缩聚反应，合成硼掺杂石墨相氮化碳(CNB)。然后，将ZrO₂与CNB混合均匀，通过煅烧法制备了不同ZrO₂含量的复合光催化剂ZrO₂-CNB。以甲基橙作为降解目标化合物，探究了ZrO₂-CNB的紫外光催化性能，并通过加入各种自由基清除剂，考察了在紫外光照射条件下光催化反应体系中生成的活性物种。研究表明：在所制备的复合光催化剂ZrO₂-CNB中，含有质量分数为0.75%的ZrO₂的ZrO₂-CNB催化剂具有最高的紫外光催化性能；在优化实验条件下，当用紫外光照射反应体系80 min时，以其为催化剂的光催化降解体系对甲基橙的降解率高达85%。ZrO₂-CNB光催化反应机制表明，h⁺和·OH在光催化降解甲基橙反应体系中起到显著作用，特别是h⁺在光催化降解反应过程中起到最主要的作用。     

电气石/TiO2复合薄膜的显微结构及光催化活性研究

在钛溶胶制备过程中加入天然电气石微粉，制得含电气石的钛溶胶，然后在紫铜表面镀膜形成含电气石的TiO2复合薄膜。用SEM研究电气石／TiO2复合薄膜的显微结构特征；用光催化降解甲基橙实验研究电气石微粉对TiO2薄膜光催化活性的影响。结果表明：电气石微粉能均匀的分布在紫铜表面的TiO2薄膜中，且形成了以电气石为核心的TiO2微粒簇，其中TiO2微粒具有阶梯层状结构和表面纳米凸起。用紫外线照射3h后，与不含电气石的TiO2薄膜相比，含质量分数为0．54％电气石的TiO2单层和双层复合薄膜对甲基橙的光催化降解率可分别提高12．1％和28．6％。     

多金属氧酸盐/二氧化钛复合光催化剂的制备及性能研究

通过溶胶-凝胶法和水热合成法制备出杂多酸(K_6P_2W_(18))/TiO_2复合光催化剂,并对其进行SEM,XRD,IR表征。采用该复合催化剂和单一TiO_2在紫外光条件下对模拟染料废水甲基橙溶液进行光催化降解,考察两者的光催化活性,并分别测出降解之后的甲基橙溶液的COD值(化学需氧量)。通过实验可以得出,杂多酸/TiO_2复合光催化剂的光催化活性明显优于单纯的TiO_2光催化剂。并且,经模拟紫外灯照射甲基橙溶液8h后,加入复合光催化剂的甲基橙溶液COD去除率达到61.98%,而加入单纯的TiO_2光催化剂的COD去除率仅达到40.63%。     

电气石原位组装纳米TiO2降解甲基橙染料废水研究

本研究采用溶胶-凝胶法在天然铁电气石微粒表面原位组装纳米TiO2,实现天然电气石微粒对纳米TiO2固定和功能增强的双重目的.XRD结果表明,TiO2/电气石复合材料的主要物相组分是锐钛矿型TiO2,其原生颗粒尺寸为45.79nm.SEM显微形貌观察发现,纳米TiO2均匀地固定在天然铁电气石微粒表面.光催化实验表明,天然铁电气石可有效提高纳米TiO2的光催化活性,在一定条件下,甲基橙染料溶液的脱色率可达到100％.电气石含量为2％的复合材料光催化活性最高;甲基橙溶液初始浓度越小,光催化活性越高;复合光催化剂的最佳用量是3.0g·L-1.     

稀土元素Ce掺杂TiO_2光催化剂制备及微波强化光催化活性

在[Bmim]PF6离子液体介质中微波辅助制备稀土元素Ce掺杂改性的TiO_2光催化剂TiO_2-Ce,以甲基橙溶液和苯酚溶液为模拟污染物,在紫外光照和微波辐射-紫外光照降解条件下考察TiO_2-Ce催化剂的光催化活性。利用荧光技术以对苯二甲酸作为荧光探针检测TiO_2-Ce催化剂表面产生的羟基自由基,并对光催化降解反应进行动力学分析,以了解光催化降解反应机理。结果表明,通过优化反应条件制得的TiO_2-Ce催化剂具有较高光催化降解活性和热稳定性,在紫外光照和微波辐射-紫外光照条件下降解60 min后,甲基橙降解率分别为98.6%和99.3%,苯酚降解率分别为96.6%和97.2%。荧光光谱分析表明,TiO_2-Ce在微波辐射-紫外光照条件下产生的羟基自由基比紫外光照多,因而微波辐射-紫外光照具有强化TiO_2-Ce降解模拟污染物作用的效果。反应动力学数据表明,TiO_2-Ce光催化降解甲基橙溶液反应呈一级反应动力学规律,其表观速率常数k最大值为0.056 2 min-1。     

活性炭掺杂WO_3/ZnO复合薄膜制备及其光催化性能研究

采用溶胶-凝胶法在铝箔上制备WO3/ZnO复合薄膜,并用活性炭对其改性,以甲基橙水溶液模拟有机污染物,研究了WO3/ZnO薄膜的光催化降解性能。实验结果表明:白炽灯照射2h、WO3质量分数为2.5%时,WO3/ZnO/铝箔对甲基橙的降解率达到78.54%;紫外光照射下降解率达到99.89%。当活性炭掺杂量为10g/L时,制得的WO3/ZnO复合薄膜均匀一致且光催化性能良好,可见光照射下甲基橙降解率达到85.71%。     

TiO_2/FeOOH/硅藻土纳米复合材料的制备和光催化性能研究

采用分子组装的方法,以硅藻土为基底制备TiO_2/硅藻土、TiO_2/FeOOH/硅藻土纳米复合材料,通过UV-Vis、TEM方法对材料进行表征,以甲基橙溶液为目标降解物探究纳米复合材料的光催化性能,结果表明,基底制备TiO_2/硅藻土、TiO_2/FeOOH/硅藻土纳米复合材料对甲基橙均有不错的降解率,其中TiO_2/FeOOH/硅藻土纳米复合材料降解率达到67.16%。     

还原石墨烯/硫化镉纳米棒复合材料制备及其光催化性能

为调控硫化镉尺寸和形貌,采用水热法合成了还原型氧化石墨烯/硫化镉纳米棒(RGO/Cd S)复合材料,采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)等方法对产物进行了表征。通过调节硫化镉颗粒成核和生长速度,在乙二胺溶剂中水热合成了结构规整的硫化镉纳米棒及与石墨烯的复合材料。紫外分析表明,RGO/Cd S禁带宽度为2.81 e V。光催化降解实验表明,RGO/Cd S对甲基橙具有良好的光催化降解作用,当甲基橙溶液质量浓度为20 mg/L、RGO/Cd S用量为0.2%(质量分数)时,在可见光下反应480 min,甲基橙降解率可达96.3%。RGO/Cd S在光催化氧化处理废水领域具有潜在的应用价值。     

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.     

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。     

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.