MCM-41介孔分子筛合成与改性的研究进展

简要介绍了MCM-41介孔分子筛的特点,应用和改性原因.综述了MCM-41介孔分子筛的合成方法,主要包括水热合成法,室温合成法,微波合成法等,列出了每种合成方法的优缺点和合成过程中的影响因素,pH值、晶化时间、晶化温度、模板剂的种类及用量等都会对MCM-41介孔分子筛的结构和孔径产生很大影响.阐述了MCM-41介孔分子筛的改性方法,包括金属杂原子取代法,如主族金属、过渡金属、稀土金属等,有机修饰或功能化法,负载型改性法,如负载金属氧化物、无机酸、杂多酸、有机碱、金属的配合物等.最后就MCM-41介孔分子筛的应用前景做了展望.     

载镍金属有序介孔氧化铝催化一氧化碳 甲烷化反应性能研究

采用传统浸渍法制备出两种负载镍金属有序介孔氧化铝,并采用BET法比表面积测定、X射线衍射 （XRD）、程序升温还原（TPR）、X射线光电子能谱分析（XPS）、透射电镜（TEM）、电感耦合等离子体发射光谱仪（ICP-OES）等多种测试技术对合成的催化剂进行表征。通过一氧化碳甲烷化反应测定其催化活性并与负载镍金属普通氧化铝进行对比。实验结果表明,镍在两种有序介孔氧化铝上主要呈两种形态,即氧化镍和偏铝酸镍。合成的介孔氧化铝比普通氧化铝镍负载量大且分散性好,这主要归结于其具有的高比表面积（300~500 m²/g）及窄孔径分布（4~ 10 nm）的稳定有序结构。催化结果表明：由于具有较高的镍负载量及较好的镍金属分散性能,因而负载镍金属有序介孔氧化铝比普通氧化铝具有较好的催化活性。     

MCM-41介孔分子筛负载咔唑类荧光分子杂化材料的合成及发光性质

通过浸渍法将5种咔唑类荧光分子负载于介孔材料MCM-41上,制备有机-无机杂化复合荧光材料,并对咔唑荧光分子和杂化复合材料的表面结构、紫外-可见吸收、荧光发射等性质进行了对比。结果表明,负载后的咔唑类荧光分子分散于MCM-41孔道上,材料热稳定性提高,在100~350℃内没有明显失重,其紫外吸收和荧光发射也发生明显蓝移(λmaxabs=331~368 nm,λmaxem=401~435 nm)。制备的杂化复合材料可用作蓝色荧光材料(λmaxem=401~435 nm)。     

MCM-41分子筛的水热合成、改性及其应用研究进展

介绍了以水热合成法为主的介孔MCM-41分子筛的合成,简述了近几年国内外介孔MCM-41材料的改性,尤其是金属掺杂改性以及杂多酸改性等方面的最新研究,详细介绍了关于功能化的MCM-41在诸多工业反应上的应用,如在烷基化催化、酯化催化、异构化催化等反应中的应用,最后对介孔MCM-41分子筛材料的发展前景以及未来亟需解决的问题进行了展望。     

金属酞菁催化氧化含硫化合物的实验研究

采用浸渍法将1,4,8,11,15,18,22,25-(异戊氧基)酞菁钴(铜,镍)分别负载到介孔分子筛MCM-41上,形成MCM-41-Co Pc,MCM-41-Ni Pc,MCM-41-Cu Pc组装体。在(20±1)℃,p H=7氧气气氛下,以各组装体为催化剂,研究了其对Na2SO3溶液的催化氧化活性。实验结果表明:各组装体具有良好的催化氧化性能,不同金属酞菁组装体表现出不同的催化活性,MCM-41-Co Pc催化剂的催化氧化性能最好。同种催化剂在不同浓度Na2SO3溶液中的催化活性也有所不同,此类催化剂可重复利用5次。负载型金属酞菁对硫化物的催化氧化作用,可以应用到油气田开发中的污水处理方面,对环保贡献了一定力量。     

ZnO改性复合材料的制备及其光谱性质鉴定

以正硅酸乙酯(TEOS)为硅源,采用水热法制备出MCM-41和SBA-15介孔材料;然后以介孔材料为主体、ZnO(氧化锌)为客体,采用锌盐浸渍-灼烧法使介孔材料负载ZnO微粒,制得功能性ZnO/MCM-41、ZnO/SBA-15复合材料,并采用X-射线衍射(XRD)、N2吸附-脱附和荧光光谱法等对复合材料的结构和性能进行了表征。研究结果表明:ZnO已成功进入介孔材料中,并且均未改变主体原有的二维六方形孔道结构,只是有序程度有一定的下降;该复合材料在400nm左右出现相对最强的吸收峰。     

浸渍液体积对有序介孔SiO2微球中Ce／Cu负载的影响

实验以Ce（NO3）3·6H2O和Cu（acac）2为原料溶于乙醇制备前驱体溶液,采用浸渍法在MCM-41有序介孔二氧化硅微球中负载Ce／Cu氧化物,最终得到负载氧化铈和氧化铜的MCM-41多孔复合微球。结果表明,Ce／Cu负载于微球的介孔中;随着浸渍液体积的增加,Ce／Cu负载量增大。     

MCM-41负载氧氮化钼的制备和表征

将MoO3和介孔材料MCM-41的机械混合物热处理得到MoO3／MCM-41复合体，将MoO3／MCM-41在氨气氛中于700℃氮化处理3h，制备了氧氮化钼负载的MCM-41催化材料。用XRD，XPS和氮吸附-脱附等手段表征了该材料。结果表明：在XRD图谱中出现氧氮化钼的微弱衍射峰，证明通过这种方法得到的材料中的氧氮化钼呈现结晶趋势。XPS谱表明：Mo存在多种化学状态。氧氮化钼负载的MCM-41的比表面积，孔体积和孔径等参数小于MoO3／MCM-41和纯MCM-41的值。     

负载型CTAB/MCM-41介孔分子筛的制备及其对溴代反应催化性能的研究

采用水热晶化法,以CTAB为模板剂合成出MCM-41介孔分子筛,后经过220℃低温焙烧4 h,可成功将CTAB固载于MCM-41,并对产物进行了XRD表征。将制备的CTAB/MCM-41催化剂用于1,7-庚二醇的溴代反应,通过对使用不同催化剂条件下反应速率的比较表明:CTAB/MCM-41的催化活性较好于未负载的CTAB。负载型的催化剂经多次使用后活性基本不变,并且能够简化反应后的分离步骤。     

采用负载铁的介孔分子筛催化模板剂合成多壁碳纳米管

用水热法合成纯硅介孔分子筛(mesoporous molecular sieves,MCM-41)。用浸渍法将MCM-41负载不同量铁制得负载铁的介孔分子筛(Fe-loading mesoporous molecular sieve,Fe/MCM-41)。以Fe/MCM-41作为催化剂催化热解乙醇制备碳纳米管。用N2物理吸附、Raman光谱、透射电镜和高分辨透射电镜等手段对样品进行了表征。结果表明:制备出了多壁碳纳米管,并且随着催化剂中Fe负载量的增加,所生成碳纳米管的管径增加。     

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。