纳米二氧化钛的表面改性技术进展

纳米二氧化钛（TiO2）是一种用途广泛的无机材料,具有广泛的用途。介绍了纳米二氧化钛的表面性能以及表面改性技术进展,指出了其今后的发展方向。     

聚合物包覆改性纳米二氧化钛的研究进展

综述了近年来国内外采用聚合物包覆法对纳米二氧化钛进行表面改性的研究工作,主要从改性原理和制备工艺的角度对聚合物包覆改性纳米二氧化钛的方法进行了分类阐述。对表面接枝法、微胶囊法和锚定位包覆法、原位聚合法、后处理改性法以及一些物理方法进行了举例介绍和比较。最后提出了目前聚合物包覆法改性纳米二氧化钛存在的问题和发展方向等。     

纳米二氧化钛表面改性与应用研究进展

纳米二氧化钛作为一种重要的纳米材料,在陶瓷材料、催化剂载体等领域有着广泛的应用。在纳米二氧化钛粉体的工业化生产中,表面处理技术是必不可少的关键步骤之一,因为改性方法的选取以及包覆物的性质会直接影响产品的应用范围。在综合分析相关文献的基础上,概述了有关纳米二氧化钛粉体表面包覆的相关机理、方法和制备过程中的控制因素等内容;主要介绍了近几年世界纳米二氧化钛粉体表面改性的研究成果及进展,并提出了今后的研究方向。     

六甲基二硅氮烷改性纳米二氧化钛工艺研究

以纳米二氧化钛为原料,水为溶剂,采用湿法工艺对纳米二氧化钛表面进行了改性研究,分别探讨了改性剂种类、改性剂用量、乳液质量分数、反应温度和反应时间对纳米二氧化钛表面改性效果的影响.结果表明,纳米二氧化钛经六甲基二硅氮烷改性处理后,在有机溶剂中的润湿性明显改善;六甲基二硅氮烷用量、乳液质量分数、反应时间、反应温度对纳米二氧化钛表面改性均有影响.较佳工艺条件:六甲基二硅氮烷质量分数为15%,乳液质量分数为30%,反应温度为90 ℃,反应时间为1 h.通过对纳米二氧化钛润湿性的测定表征纳米二氧化钛的改性效果.     

纳米二氧化钛的表面改性研究

初步研究了硬脂酸对纳米二氧化钛陶瓷粉体的表面改性作用及其对粉体极性和流动性的影响。实验结果表明 ,硬脂酸中的羧基与纳米二氧化钛粉体颗粒表面的羟基发生了类似于酸和醇的酯化反应 ,并在其表面形成单分子膜。经过表面改性的纳米二氧化钛由极性转化为非极性 ,同时表现出良好的流动性能     

纳米二氧化钛的表面改性研究

采用不同的表面活性剂三乙醇胺、十二烷基硫酸钠(SDS)、聚乙烯吡咯烷酮(PVP)对纳米二氧化钛进行表面改性处理。对不同表面活性剂处理的纳米二氧化钛采用沉降法来表征纳米粉体在水中的分散性,目的是日后用来制备更均匀的复合薄膜。研究结果表明:三乙醇胺与其他两种表面活性剂混合使用较单种表面活性剂处理后的纳米二氧化钛其分散效果会更好。分散纳米二氧化钛效果最佳的表面活性剂为三乙醇胺与十二烷基硫酸钠的混合物(质量比为2∶1),表面活性剂总用量为30%(质量分数),采用搅拌和超声时间都为15 min,纳米二氧化钛的初始沉降时间为2.5 h,完全沉降时间大于120 h。     

纳米二氧化钛改性及其在涂料中的应用

简要介绍了纳米二氧化钛表面改性的常用方法,并综述了纳米二氧化钛在抗菌涂料、净化空气涂料、汽车面漆、耐老化涂料等方面的应用进展。     

纳米TiO_2负载方法概述

近年来人们对二氧化钛的研究日益深入,纳米二氧化钛作为一种经济有效的光催化材料受到人们的普遍关注,但是纳米TiO2在使用上存在大量问题牵制了其进步应用与推广。为了解决这个难题,目前较为有效的方法是通过负载使纳米二氧化钛改性。本文介绍了核壳与包覆的两种负载理论并介绍了化学及物理两类负载方法。     

纳米二氧化钛表面改性研究

纳米二氧化钛有机表面改性的研究，研究了纳米二氧化钛与不同量的有机表面改性剂月桂酸钠混合研磨、研磨不同的时间同研磨包覆后纳米二氧化钛在蓖麻油中溶解时间的规律，表明研磨时间长，溶解时间则变短，当混合研磨时间一定时，表面处理剂含量大则溶解时间会缩短。     

纳米二氧化钛光催化剂的制备及其表面改性的研究进展

简述了纳米二氧化钛材料的结构、性能及光催化机理,综述了其常用的制备方法,且针对纳米二氧化钛应用的局限性,重点总结了目前常见的二氧化钛表面改性的方法及研究进展。     

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。