Z型异质结In2O3/CdS的合成及光降解抗生素研究

为了拓展对可见光的吸收范围、抑制光生载流子的复合,并增强催化剂的光催化性能,通过将CdS原位生长于In_2O_3表面的方法制备出In_2O_3/CdS催化剂。结果表明:在可见光照射60 min后,In_2O_(3/)CdS异质结对盐酸强力霉素的去除效率达84.0%,远高于In_2O_3和CdS单体的降解效率,降解过程符合一级动力学。In_2O_3/CdS对盐酸强力霉素的降解速率常数为0.028 min~(-1),分别为In_2O_3和CdS单体的13.7倍和1.5倍。自由基捕获实验表明:·O_2~-和·OH是主要的活性基团,光催化性能的提高主要得益于Z型异质结的形成,有效加速了光生电子和空穴的转移和分离效率。     

NiO/In_2O_3 p-n结型光催化剂的制备及其降解盐酸强力霉素研究

采用水热合成法制备出了具有p-n异质结结构的立方形氧化铟表面负载片状氧化镍复合光催化剂。SEM,XRD和UV-VIS,FT-IR等方法对催化剂的晶相组成、微观结构、化学键组成以及吸光性能等进行了表征。结果表明,NiO/In_2O_3复合光催化剂的形成符合牺牲模板机理。片状氧化镍的负载使复合光催化剂的吸收带边发生了明显的红移,并在可见光区产生响应。光催化降解盐酸强力霉素实验表明,与单一的In_2O_3相比,氧化镍颗粒的负载使二氧化铟的光催化效果在紫外-可见光区有了明显地提高,且在中性以及碱性条件下的光催化效果最佳,降解效率达到93%,其主要原因应归功于氧化镍晶粒与二氧化铟晶粒紧密接触形成p-n异质结,有助于催化剂表面光生电子和空穴的快速分离。     

高可见光活性TiO2-BiOI的制备及其光催化性能

以钛酸丁酯、亚氨基二乙醇、碘化钾和五水合硝酸铋为原料,通过溶剂热法将TiO_2均匀地负载到Bi OI花状微球上,制备了TiO_2-Bi OI复合光催化剂。通过XRD、XPS、SEM、TEM和UV-Vis-DRS对样品进行了表征。以甲基橙为目标降解物,测定了TiO_2-BiOI复合光催化剂在可见光下的光催化性能。结果表明,纳米TiO_2的加入为复合光催化剂比表面积的增加作出了贡献,TiO_2与Bi OI之间形成的异质结结构可以促进光生电子和空穴分离,从而达到提高复合光催化剂光催化性能的目的。n(Ti)∶n(Bi)=0.4∶1.0的TiO_2-BiOI复合光催化剂表现出最佳的光催化降解性能,可见光(λ420 nm)照射60 min,其对甲基橙的降解率达到95%,远高于纯的TiO_2和Bi OI光催化剂。     

g-C_3N_4/TiO_2复合光催化剂制备及活性研究

光催化技术可直接利用太阳光实现有机污染物的深度降解,传统光催化剂二氧化钛存在可见光转换效率低,光生电子-空穴对容易复合等缺点。采用简单的化学法制备了二维纳米片层石墨相氮化碳(g-C_3N_4)包覆二氧化钛纳米粒子复合光催化剂(g-C_3N_4/TiO_2),利用XRD、UV-Vis、SEM、PL等手段对光催化剂的结构性能进行了表征,并考察了复合材料在紫外、可见光下降解亚甲基蓝(MB)、苯酚及双酚A的性能。研究结果表明:二维纳米片层g-C_3N_4的引入可以实现复合材料对可见光的吸收利用,并且可以极大地提高光生电子空穴在界面处的分离效率。在紫外光照射20 min后,5%g-C_3N_4/TiO_2复合物对染料亚甲基蓝(MB)的降解率高达90%,并且在重复使用5次之后仍具有较高的光催化性能。     

RGO/In_2S_3复合修饰TiO_2纳米管阵列及其光催化应用

采用脉冲电沉积法将In_2S_3纳米粒子沉积在TiO_2纳米管阵列(NTs)上,得到In_2S_3–TiO_2 NTs。然后通过脉冲电沉积法将石墨烯薄膜修饰在In_2S_3–TiO_2 NTs上,制备出RGO/In_2S_3–TiO_2 NTs复合材料。通过光电流测试和2,4-二氯苯氧乙酸(2,4-D)降解试验表征了RGO/In_2S_3–TiO_2 NTs的光电性能和光催化性能。结果表明:相对于纯TiO_2 NTs,RGO/In_2S_3–TiO_2 NTs复合材料的光生电子-空穴对的复合率更低,对可见光的吸收更强。光催化180 min后,RGO/In_2S_3–TiO_2 NTs复合材料对2,4-D的降解效率高达93.36%,重复使用5次后仍有90.70%。     

热解法合成增强光催化活性的In2O3-TiO2纳米管

通过热解法分解InCl_3形成In_2O_3并均匀沉积于通过阳极氧化法制备的TiO_2纳米管(TNAs)表面,并通过光催化降解罗丹明B(RhB)来测试In_2O_3-TNAs的光催化活性。结果表明,复合In_2O_3后TNAs的光催化活性显著提升。此外热解沉积工艺简单、成本低,有利于光催化剂的批量、工业化生产,为金属氧化物半导体的沉积提供了新思路。     

Au/TiO_2纳米片异质结薄膜的制备及其光催化性能研究

采用微波辅助化学还原法制备Au/TiO_2纳米片异质结薄膜(Au/TiO_2NSF)光催化剂,通过XRD、SEM、UVVis、PL和光电流响应对其进行表征,并考察了其在模拟太阳光下降解水相中有机染料亚甲基蓝(MB)和清除气相中氮氧化物(NO_x)的性能。结果表明,Au/TiO_2NSF光催化剂对光的吸收利用好、光生电子-空穴对复合几率小,其光催化降解MB和清除NO_x的活性比TiO_2NSF高,其中1.0Au/TiO_2NSF的效果最好。     

Fe~(3+)-CdS/TiO_2复合半导体光催化剂的制备与表征

采用溶胶-凝胶法制备了系列不同配比的Fe3+-CdS/TiO2光催化材料,用TEM、EDS、XRD、UV-vis等技术对其形貌、结构和光吸收特性进行了表征。以亚甲基蓝(MB)的脱色降解为模型反应,考察了光源、煅烧温度、煅烧时间、掺杂Fe3+和CdS对催化剂催化性能的影响。结果表明,Fe3+掺杂和CdS半导体复合相结合的技术,可以使TiO2对光的响应拓展到整个紫外-可见光区;当n(Fe3+)∶n(CdS)∶n(TiO2)=0.005∶1∶1、煅烧温度为300℃、煅烧时间为1 h、光源为太阳光时,Fe3+-CdS/TiO2的光催化活性最高,在1 h内可以使亚甲基蓝(MB)溶液的降解率达98.62%。     

溶剂热法制备高可见光活性TiO2-BiOI光催化剂及其光催化性能研究

通过溶剂热法将TiO2均匀负载到了BiOI花状微球上，制备了TiO2-BiOI复合光催化剂。XRD，FT-IR，XPS，SEM，TEM和UV-Vis-NIR对样品进行了表征。以甲基橙为目标降解物，研究了TiO2-BiOI复合光催化剂在可见光下的光催化性能。研究结果表明，纳米TiO2的复合为增加复合光催化剂的比表面积作出了贡献，TiO2与BiOI之间形成的异质结构可以促进光生电子和空穴分离，从而达到提高复合光催化剂光催化性能的目的。Ti:Bi摩尔比为0.4的TiO2-BiOI复合光催化剂表现出最佳的光催化降解效率，可见光（λ>420 nm）照射60 min对甲基橙的降解率达到了95%，光催化效率要远好于纳米TiO2和纯的BiOI光催化剂。     

α-Fe_2O_3改性空心玻璃微球/ZnIn_2S_4复合催化剂的制备及增强型光催化性能

采用改良后的水热法制备空心玻璃微球(HGM)/ZnIn_2S_4/α-Fe_2O_3漂浮型复合光催化剂。以HGM为载体,首先制备HGM/ZnIn_2S_4复合微球,然后利用自制的纳米棒状α-Fe_2O_3进一步改性,得到HGM/ZnIn_2S_4/α-Fe_2O_3漂浮型复合光催化剂。以六价铬(Cr~(6+))为目标污染物,研究了α-Fe_2O_3含量、催化剂投加量和原液pH值对复合催化剂光催化活性的影响。结果表明:纳米棒状α-Fe_2O_3与六方相型ZnIn_2S_4形成异质结构并均匀负载在HGM表面,形成HGM/ZnIn_2S_4/α-Fe_2O_3复合光催化剂,与α-Fe_2O_3粉体和HGM/ZnIn_2S_4复合微球相比,HGM/ZnIn_2S_4/α-Fe_2O_3漂浮型复合光催化剂的催化性能显著提高,且再循环后仍具有良好的光催化效率,并提出了HGM/ZnIn_2S_4/α-Fe_2O_3的增强型光催化机制。     

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。