铁掺杂TiO_2/高岭土复合矿物光催化剂的制备及其光催化活性的研究

以钛酸丁酯为原料,以高岭土为载体,采用溶胶-凝胶法制备了铁掺杂TiO2/高岭土复合矿物光催化剂。采用XRDI、R等测试手段对铁掺杂TiO2/高岭土复合矿物光催化剂进行了表征,并通过对偶氮砷Ⅲ的降解反应,考察了其光催化活性,实验结果表明,该复合矿物光催化剂在铁的掺杂量0.75%、被降解溶液的pH值在3.5时,对偶氮砷Ⅲ的脱色率可达到100%。     

TiO2纳米管制备与掺杂改性的研究进展

本文总结近年来TiO2纳米管制备与掺杂改性的研究进展.介绍TiO2纳米管的制备方法以及纳米管的形成机理,讨论影响阳极氧化法制备TiO2纳米管的主要因素.总结使用不同元素对TiO2纳米管进行掺杂的方法以及效果,重点介绍N掺杂的不同方法以及提高TiO2纳米管性能的机理.介绍通过量子点和有机染料对TiO2纳米管进行表面改性的...     

多种光源下氮掺杂TiO_2光催化降解染料废水的研究

以尿素为氮源,采用溶胶-凝胶法制备了氮掺杂纳米TiO2粉末,以甲基橙溶液为模拟染料废水,分别在可见光、模拟太阳光和紫外光条件下,研究了氮掺杂纳米TiO2光催化降解染料废水的性能。结果表明:氮掺杂可以提高TiO2的可见光催化活性;氮含量和煅烧温度对氮掺杂TiO2光催化活性影响较大,n(N)∶n(Ti)为10%且经500℃煅烧的氮掺杂TiO2在可见光和模拟太阳光下均具有最佳的光催化活性;然而在紫外光下,氮掺杂TiO2的光催化活性低于未掺杂的TiO2样品。     

稀土La掺杂二氧化钛纳米管的微波法制备

微波法制备纳米管是利用微波对水的介电作用进行的,它是一种合成纳米管的新型工艺方法。本研究以溶胶-凝胶法制备的掺杂TiO2纳米粉体为前体,利用微波法制备TiO2纳米管,用透射电子显微镜和扫描电子显微镜对其进行表征。结果表明:以TiO2纳米粉体为前体,利用微波法可以制得形貌比较完整的TiO2纳米管,其外径为8～15nm,内径为5～10nm,长50～100nm。未经HCl酸洗的TiO2纳米管在电镜下结构非常完整,而经过HCl酸洗的TiO2纳米管在电镜下观察则发现其局部遭到破坏。     

非金属元素掺杂二氧化钦纳米管的研究进展

TiO2纳米管对大部分可见光不能进行有效地吸收利用,成为其实际应用的"瓶颈".非金属元素掺杂TiO2纳米管可以有效地减小TiO2带隙,拓展光谱响应范围.本文介绍了非金属掺杂TiO2纳米管的原理和制备方法,对非金属单一元素掺杂、非金属与其它元素共掺杂TiO2纳米管的研究现状进行了详细的评述,指出了非金属掺杂TiO2:纳米管过程中存在的问题和未来的研究方向.     

非金属元素掺杂二氧化钛纳米管的研究进展

TiO2纳米管对大部分可见光不能进行有效地吸收利用,成为其实际应用的"瓶颈"。非金属元素掺杂TiO2纳米管可以有效地减小TiO2带隙,拓展光谱响应范围。本文介绍了非金属掺杂TiO2纳米管的原理和制备方法,对非金属单一元素掺杂、非金属与其它元素共掺杂TiO2纳米管的研究现状进行了详细的评述,指出了非金属掺杂TiO2纳米管过程中存在的问题和未来的研究方向。     

柔性TiO2纳米管薄膜电极的制备及其光电性能

采用水热合成法制备出TiO2纳米管,通过XRD、TEM和氮气等温吸附-脱附仪等测试手段对TiO2纳米管进行了表征.用烧结的TiO2纳米管和P25粉末混合制成薄膜电极,并研究了薄膜电极的表面形貌、染料吸附量和光电性能.研究表明,加入TiO2纳米管可以制备出机械稳定的薄膜;掺杂TiO2纳米管的含量越多,薄膜电极的染料吸附量越大;掺杂5%烧结纳米管粉末的薄膜电极的光电性能最好,其短路电流可达3.25mA,光电转换效率达到1.67%.     

氮掺杂纳米TiO2光催化性能的研究

以钛酸丁酯和硝酸氮为主要原料,采用溶胶-凝胶法制备不同掺氮比的纳米TiO2(纳米N-TiO2)光催化剂。研究了不同的氮钛比、焙烧温度对氮掺杂纳米TiO2降解甲基橙溶液催化效果的影响。利用XRD、SEM方法对氮掺杂纳米TiO2的晶体结构及微观形貌进行了表征。结果表明:通过氮掺杂纳米TiO2,抑制了纳米TiO2晶粒的生长和晶型的转变,同时提高了TiO2的光催化活性。在紫外线灯的照射下,煅烧温度为500℃,N/Ti的原料配比为0.5%,制备的催化剂可达到最大的降解效果(为92.49%)。     

TiO_2纳米管电极金属离子掺杂的表征

采用浸渍法对TiO2纳米管电极进行Zn2+、Fe3+、Cu2+离子的掺杂改性,并进行了各种性能表征.扫描电镜(SEM)及X射线衍射光谱(XRD)结果表明,金属离子掺杂后的TiO2纳米管电极依然保持了良好的表面形态及锐钛矿晶型,纳米管的直径为60—100 nm,其晶面主要为101面;可见紫外漫反射光谱(DRS)分析表明,进行掺杂的TiO2纳米管电极的光学性质有不同程度的改变,Zn2+、Fe3+和Cu2+掺杂的TiO2纳米管电极的禁带宽度分别为3.37 eV3、.14 eV、2.86 eV.这表明掺Cu2+的TiO2纳米管电极的吸收边带发生了明显的红移.     

氮掺杂纳米二氧化钛的制备及其光催化性能

以三乙醇胺为氮源采用水热法制备了氮掺杂纳米TiO2光催化剂,采用XRD、TEM和UV—vis／DRS分析、表征氮掺杂对TiO2微晶尺寸、晶体结构、表面组成与光学性能的影响,并通过降解甲基橙溶液研究其光催化活性。结果表明：制得的氮掺杂二氧化钛均为锐钛矿型,粒径约为10nm,a掺杂引起光催化剂的吸收波长向可见光区红移。当pH=11．0,300℃焙烧3h时制得的氮掺杂TiO2光催化活性最强,甲基橙50min的降解率达98％。     

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。