掺杂改性TiO2紫外光催化降解甲苯的动力学研究

探索了用水热反应制备的锐钛型掺杂改性的TiO2(即A-TiO2)对甲苯的光催化降解作用.通过分析甲苯的初始浓度、TiO2用量、掺铁量和溶液的pH值对光催化速率的影响,研究改性TiO2催化甲苯的动力学行为;结果表明:甲苯溶液初始浓度为1.2 g/L(pH =5)、催化剂用量为2.0 g/L,掺铁量为4％(摩尔分数)、室温下紫外光照(λ=365 nm)反应2h,甲苯的降解率D％(47.93％)和表观反应速率常数k达到最大值0.2523 h-.光催化反应符合L-H动力学方程,降解过程表现为拟一级反应.     

自制改性TiO2光催化降解对硝基苯胺的动力学研究

本文采用水热法制备了改性TiO2粉末,用XRD测定了样品的晶型,研究了以自制催化剂对对硝基苯胺的光催化降解效果.通过分析初始浓度、TiO2用量和掺铁量对光催化速率的影响,研究改性TiO2催化对硝基苯胺的动力学行为;结果表明:对硝基苯胺溶液初始浓度为25 mg/L(pH =7)、催化剂用量为0.2 g/L,TiO2掺铁量为0.2％(摩尔分数)、室温下紫外光照(λ =365 nm)反应2.5h,对硝基苯胺的降解率为55.6％,表观反应速率常数,达到最大值0.3152 h-1.光催化反应符合L-H动力学方程,降解过程表现为拟一级反应.     

铁掺杂二氧化钛光催化降解硝基苯的动力学研究

采用水热法制备了锐钛矿型铁掺杂TiO2光催化剂,以分析初始浓度、催化剂用量、TiO2的掺铁量、溶液的pH值对光催化速率的影响为基础,研究了铁掺杂二氧化钛催化硝基苯动力学行为.结果表明:可见光照射下,硝基苯溶液初始浓度为50 mg/L、TiO2掺铁量为0.05％(物质的量分数)、催化剂用量为1.2 g/L,溶液pH为3、室温下光照反应2.5h,硝基苯的降解率和反应速率常数k达到最大值.光催化反应符合Langmuir-Hinshelwood动力学规律,硝基苯的降解过程表现为一级反应,k为0.0028 min-1.     

纳米二氧化钛光催化降解染料废水动力学研究

以纳米二氧化钛为光催化剂,研究了光催化降解染料废水溶液的动力学规律及溶液的pH值、TiO2投加量和染料起始浓度对光催化降解活染料废水动力学的影响。结果表明,该反应符合Langmuir-Hinshelwood(L-H)动力学模型,且光催化过程符合一级反应动力学方程,一级反应动力学常数(K')随溶液pH值及染料起始浓度的降低而增大;TiO2的最佳投加量为2.0 g/L,低于或超过该值都会导致降解速率的下降。     

氮掺杂二氧化钛光催化降解亚甲基蓝的动力学研究

以分析MB初始浓度,催化剂用量以及pH值对光催化速率的影响为基础,研究了氮掺杂二氧化钛催化亚甲基蓝动力学行为;结果表明催化反应符合Langmuir等温吸附规律,pH值为3时降解速率达到最大值,并且光催化速率的变化随着催化剂用量呈现饱和现象.     

紫外光照下用自制掺Fe~(3+) TiO_2催化降解二甲酚橙

以水热法制备了掺Fe~(3+)的TiO_2粉末,用XRD测定了晶型,研究了以其为催化剂对二甲酚橙的光催化降解作用,分析TiO_2投放量、掺Fe~(3+)量、二甲酚橙的初始浓度和溶液的初始pH等对光催化降解效率的影响。结果表明,用自制的掺Fe~(3+)A-TiO_2光降解二甲酚橙溶液的最佳条件是:催化剂用量为1.2 g/L,TiO_2掺铁量为7%(摩尔分数)、二甲酚橙溶液初始浓度为300 mg/L(pH=6)、室温下紫外光照(λ=365 nm)反应30 min,二甲酚橙的降解率(D%)最大,达到67.9%。     

紫外光照下用自制掺Fe~(3+) TiO_2催化降解二甲酚橙

以水热法制备了掺Fe⁽³⁺⁾的TiO_2粉末,用XRD测定了晶型,研究了以其为催化剂对二甲酚橙的光催化降解作用,分析TiO_2投放量、掺Fe(3+)的TiO_2粉末,用XRD测定了晶型,研究了以其为催化剂对二甲酚橙的光催化降解作用,分析TiO_2投放量、掺Fe⁽³⁺⁾量、二甲酚橙的初始浓度和溶液的初始pH等对光催化降解效率的影响。结果表明,用自制的掺Fe(3+)量、二甲酚橙的初始浓度和溶液的初始pH等对光催化降解效率的影响。结果表明,用自制的掺Fe⁽³⁺⁾A-TiO_2光降解二甲酚橙溶液的最佳条件是:催化剂用量为1.2 g/L,TiO_2掺铁量为7%(摩尔分数)、二甲酚橙溶液初始浓度为300 mg/L(pH=6)、室温下紫外光照(λ=365 nm)反应30 min,二甲酚橙的降解率(D%)最大,达到67.9%。     

Ag掺杂二氧化钛光催化降解甲基橙的研究

以二氧化钛为钛源,硝酸银为银源,制备了掺银的TiO2光催化剂,以分析TiO2的掺银量、催化剂用量、溶液的初始浓度的影响为基础,研究了掺银的TiO2光催化剂催化降解甲基橙的动力学过程。结果表明:在40 w紫外光条件下,初始浓度为5 mg/L的甲基橙溶液,掺银量为5%(摩尔分数),催化剂用量为0.9 g/L,室温下反应2 h时后甲基橙的降解率达到93%;银掺杂TiO2光催化降解甲基橙的反应可以用一级反应动力学方程进行描述。     

β2-SiW11Co/PANI光催化降解孔雀石绿的研究

以β2-SiW11Co/PANI为光催化剂。在紫外灯辐射下,研究了模拟染料废水孔雀石绿溶液的光催化降解的反应,考察了催化剂投加量、孔雀石绿的初始浓度、溶液的pH值对催化脱色效果的影响。实验结果表明,当溶液酸度为pH2,催化剂最佳用量为3 mg/L,浓度为10 mg/L的孔雀石绿溶液在15 W的紫外灯下照射300 min降解率可达96.4%。     

甲苯的光催化降解及其动力学研究

进行了以自制锐钛型Fe3+-TiO2催化降解甲苯的研究,在自制的光催化反应器中,室温下以40 W白炽灯为光源,分析了TiO2的掺Fe3+量、催化剂投放量、甲苯初始浓度和溶液初始pH等因素的影响.结果表明:自制锐钛型Fe3+-TiO2能较有效地催化降解甲苯.在pH为2,TiO2掺Fe3+量为5％(物质的量分数)、催化剂投放量为2.0 g/L时对1.2 g/L甲苯的去除率在5h内可达60％以上.甲苯的降解过程表现为一级反应,表观反应速率常数k为0.0666 h-1,反应可用Langmuir-Hinshelwood动力学方程描述.     

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。