聚苯胺改性负载型纳米二氧化钛的研究

采用悬浮聚合法制备聚苯乙烯微珠载体,通过矿化接枝技术将溶胶-凝胶法制备的纳米二氧化钛负载在微珠载体上,制成负载型纳米二氧化钛光催化剂。利用导电聚苯胺对负载型纳米二氧化钛光催化剂进行可见光改性研究,通过XRD,SEM等方法对负载型纳米二氧化钛光催化剂进行表征;通过光催化降解甲基橙实验评价了导电聚苯胺改性负载型纳米二氧化钛光催化剂在可见光条件下的光催化活性。实验结果表明：导电聚苯胺对负载型纳米二氧化钛光催化剂的改性,可有效改善负载型纳米二氧化钛光催化剂在可见光条件下的光催化性能,降解率提高了24.5%。     

二氧化钛-碳纳米管复合材料的制备和光催化性能

利用水热法制备了分别掺杂负离子粉和二氧化硅的二氧化钛溶胶,并分别以活性炭、碳纳米管作为载体进行负载,制备得到二氧化钛-碳纳米管(TiO_2-CNTs)复合材料;通过XRD及SEM对样品进行了表征;并以甲基橙为目标降解物评价了复合材料的光催化性能。XRD结果表明虽然负载体二氧化钛的峰的一致的;SEM的结果表明CNTs负载的TiO_2复合催化剂其晶粒尺寸变小,其中掺杂改性的TiO_2催化剂粒径更小。光催化降解实验结果表明碳纳米管作为载体所制复合材料光催化性能优于活性炭负载的。掺杂改性的TiO_2催化剂对甲基橙的光催化降解性能优于纯TiO_2催化剂,而掺杂二氧化硅的二氧化钛光催化性能优于掺杂负离子粉的。     

二氧化钛/微球光催化剂的溶胶-凝胶法制备与性能研究

以溶胶 凝胶法在自制硅酸盐微球载体上制备纳米二氧化钛 ,采用XRD ,SEM ,Raman等测试手段对样品进行表征 ,并以甲基橙作为目标物研究其光催化性能。实验发现 ,负载在微球表面的二氧化钛粒径为 2 0～ 30nm ,且分布均匀 ,晶型为锐钛矿相 ,该样品对甲基橙具有较高的光催化降解能力。     

纳米二氧化钛管阵列的制备及其光催化氧化降解甲基橙性能的研究

本文采用电化学阳极氧化法制备了管径为90—150nm的纳米管阵列。采用SEM和XRD对制备的二氧化钛纳米管阵列进行了表征。考察了焙烧温度对阳极氧化法制备纳米二氧化钛管阵列晶形结构的影响。将所制备的纳米管用于光催化降解甲基橙反应,考察了其在通气和不通气条件下光催化降解甲基橙的性能。结果显示：在550℃下焙烧的纳米管阵列具有良好的催化活性;反应器中通氧气可以提高纳米二氧化钛对甲基橙的光催化活性。     

纳米TiO2/硅藻土复合光催化材料的制备与表征

采用酸浸法对硅藻土进行了提纯处理,以四氯化钛为前驱体,用水解沉淀法对提纯前后的硅藻土分别进行了表面包覆改性,制备了硅藻土负载TiO2复合光催化材料.通过SEM、XRD等测试手段对复合材料的成分、物相、形貌等进行了表征,并用甲基橙溶液的光催化降解率对材料的光催化性能进行了评价.结果表明,负载在硅藻土表面的TiO2晶型为锐钛型,晶粒平均尺寸12 nm,纳米TiO2在硅藻土表面形成了均匀的包覆;这种硅藻土负载纳米TiO2复合光催化材料具有很强的光催化活性,对10 mg/L的甲基橙溶液1.5 h的脱色率达99%以上.     

PET基二氧化钛光催化涂层的制备及性能研究

采用旋涂法在聚对苯二甲酸乙二醇酯(PET)薄膜基材上制备出二氧化钛光催化涂层。为制备纳米二氧化钛(TiO_2)粒子富集于涂层与空气界面处的光催化涂层,采用偶联剂1H,1H,2H,2H-全氟辛基三乙氧基硅烷对纳米TiO_2粒子进行了表面氟化改性。采用SEM、紫外-可见分光光度计和接触角测定仪对PET基光催化涂层的结构进行了表征。结果表明,所制备的光催化涂层厚度约为4~6μm,且在可见光区具有极高的透明性。以甲基橙为目标污染物考察了光催化涂层的光催化活性,结果表明,含有氟化纳米TiO_2粒子的光催化涂层比含有纯纳米TiO_2粒子的光催化涂层具有更高的光催化活性,纳米TiO_2粒子表面氟化改性使纳米TiO_2粒子富集于涂层与空气界面处,这种粒子的分布状态有利于光催化活性的提高。     

壳聚糖/纳米纤维素/石墨烯改性纳米TiO2复合膜光催化降解性能

以氧化石墨烯改性纳米二氧化钛为光催化活性成分,通过流延成型法制备了壳聚糖/纳米纤维素/石墨烯改性纳米TiO₂光催化复合膜。利用热重分析仪(TG)、傅里叶红外光谱仪(FTIR)和扫描电子显微镜(SEM)对复合膜的结构进行表征。研究了壳聚糖/纳米纤维素/改性纳米TiO₂复合膜的力学性能,对比了复合膜对亚甲基蓝及甲基橙的光催化降解性能。结果表明,改性纳米TiO₂的添加提高了壳聚糖复合膜的力学性能及耐热性能。改性纳米TiO₂质量分数为4%的复合膜抗拉强度最大,达到43 MPa。改性纳米TiO₂质量分数为2%的复合膜断裂伸长率最大为13.6%。在模拟溶液质量浓度为20 mg/L时,改性纳米TiO₂质量分数为2%的复合膜对亚甲基蓝降解率最大,为51.7%。改性纳米TiO₂质量分数为4%的复合膜对甲基橙降解率最大,为42.2%。模拟溶液初始浓度愈高,则复合膜对亚甲基蓝及甲基橙降解率均降低。     

铜锡改性纳米二氧化钛光催化氧化还原性能的研究

在复合半导体基础上，采用超声浸渍法对催化剂表面作进一步铜改性，制备了铜锡改性的纳米二氧化钛光催化剂CuOx-SnO2／TiO2，考察了表面铜改性、二氧化锡复合对催化剂光催化氧化还原性能的影响．结果表明，表面铜改性和复合都有利于提高催化剂光催化氧化还原能力，二者间表现出相互增强的作用．结合XRD、XPS、TEM等催化剂表征结果，对铜锡改性纳米二氧化钛光激发机制进行了讨论，提出了二氧化碳光催化还原的可能机制．     

膨胀石墨负载纳米二氧化钛光催化剂的制备、表征与其光催化性能

采用Degussa P25(P25)改性溶胶-凝胶法制备膨胀石墨(exfoliated graphite,EG)负载纳米二氧化钛(TiO2)光催化材料.用X射线衍射分析、扫描电镜、Brunauer-Emmett-Teller(BET)比表面积等分析技术对样品结构进行表征.讨论了材料制备过程中热处理温度、负载次数、改性溶胶中P25浓度对其结构与光催化剂活性的影响.结果表明:TiO2以纳米颗粒的形式牢固负载在EG薄片表面.具有疏松多孔蠕虫状结构的EG为TiO2提供高浓度的三维降解环境.当P25浓度为5g/L时,与EG复合的材料经500℃热处理3h后,对甲基橙溶液的降解效能最高.     

负载型ZnO光催化降解有机废水

采用化学浴沉积法制备了ITO玻璃负载ZnO纳米膜,以甲基橙溶液作为模拟有机废水,研究了其光催化性能,考察了光催化时间、光催化膜循环使用次数对甲基橙模拟废水降解率的影响。试验结果表明,制备的纳米ZnO膜纯度高,结构均匀有序;在紫外光下照射4h,对甲基橙的降解率达到76.8%;简单冲洗干燥后即可重复使用,循环使用5次,对甲基橙的降解率仍良好。     

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。