功能材料纳米氧化锌粉体合成

采用直接沉淀法合成纳米氧化锌粉体。考察了锌源、沉淀剂、表面活性剂和反应介质等因素对纳米氧化锌粒径的影响。采用沉降法对产品粒径及粒径分布进行初步测量和判断,并采用SEM和XRD对产品进行表征。结果表明,以硝酸锌和碳酸钠为原料、十二烷基苯磺酸钠为表面活性剂合成的纳米氧化锌粉体,粒径小,粒径分布窄,平均粒径在50～100 nm。     

超声波直接沉淀法制备纳米氧化锌及改性研究

以硝酸锌和无水碳酸钠为原料,把超声波引入到直接沉淀法中,同时用溴化十六烷基三甲基铵(CTAB)作为表面活性剂,合成出粒径小、分布均匀且团聚现象明显减弱的纳米氧化锌,并用TG-DTA,XRD,SEM等分析手段对制得的产物进行表征,找出合成的最佳条件.同时,还以油酸作为改性剂对所制得的纳米氧化锌进行表面改性,以FT-IR等测试手段对其改性原理进行简单探讨,并通过测定活化指数对改性效果进行分析.     

三聚磷酸钠辅助沉淀法制备纳米氧化锌及其抗菌性能研究

探讨了纳米氧化锌制备过程中的团聚问题及其抗菌性能。以三聚磷酸钠为表面活性剂,辅助沉淀法制备了纳米氧化锌粉体,用XRD,TEM,TG-DTA,BET等方法对产物进行了表征。结果表明:所得纳米氧化锌为高分散的球形颗粒,属于六方纤维矿的单晶结构,平均粒径为20 nm,比表面积可达70.478 1 m2/g。线性三聚磷酸钠与锌离子的络合作用,可以使前躯体均匀成核,并通过空间位阻抑制颗粒间的聚集,避免团聚的发生。采用杯碟法测试纳米氧化锌的抑菌活性。结果显示,纳米氧化锌对金黄色葡萄球菌、大肠埃希氏菌和沙门氏菌具有很好的抑菌活性,纳米氧化锌比表面积大小决定其抑菌活性。     

多元醇还原法制备FePt纳米颗粒

以乙酰丙酮铁和氯铂酸作为Fe源和Pt源,1,2-十二烷二醇为还原剂,通过多元醇还原法制备出单分散的FePt纳米颗粒,研究了表面活性剂油酸和油胺对FePt纳米颗粒形貌和分散性的影响。结果显示,未使用表面活性剂制得的FePt纳米颗粒粒度范围是1.0～6.0 nm,平均粒径为3.4 nm;使用油酸和油胺制得的FePt纳米颗粒粒度范围是2.5～5.5 nm,平均粒径4.1 nm。通过XRD、TEM和VSM分析表明,油酸和油胺修饰的FePt纳米颗粒为面心立方结构,形状近似球形,分散性良好,粒径分布较未使用表面活性剂时变窄;VSM显示其矫顽力趋近于0,呈现超顺磁性。     

三聚磷酸钠辅助沉淀法制备纳米氧化锌及其抗茵性能研究

探讨了纳米氧化锌制备过程中的团聚问题及其抗菌性能.以三聚磷酸钠为表面活性剂,辅助沉淀法制备了纳米氧化锌粉体,用XRD,TEM,TG-DTA,BET等方法对产物进行了表征.结果表明:所得纳米氧化锌为高分散的球形颗粒,属于六方纤维矿的单晶结构,平均粒径为20 nm,比表面积可达70.478 1 m2/g.线性三聚磷酸钠与锌离子的络合作用,可以使前躯体均匀成核,并通过空间位阻抑制颗粒间的聚集,避免团聚的发生.采用杯碟法测试纳米氧化锌的抑菌活性.结果显示,纳米氧化锌对金黄色葡萄球菌、大肠埃希氏菌和沙门氏菌具有很好的抑菌活性,纳米氧化锌比表面积大小决定其抑菌活性.     

表面改性纳米氧化锌的制备及其性能表征

通过均相化学沉淀法,在合成纳米氧化锌的同时对其进行表面改性。对合成产物进行了XRD、TEM和TGA等性能表征;比较不同加料方式、分散剂对氧化锌粒径的影响,分析讨论了分散剂可能的分散作用机理。在最优化条件下得到粒径为6nm~25nm之间粒径分布均匀的纳米氧化锌,且得到的纳米粉体基本上不存在团聚现象,分散性好。     

表面活性剂对水热合成纳米氧化锌粉性能的影响

采用水热合成制备纳米氧化锌粉。主要研究了聚乙二醇和三聚磷酸钠等七种表面活性剂对纳米氧化锌粉物相和形貌的影响。采用XRD、TEM和荧光光谱仪对样品进行了表征。结果表明:添加聚乙二醇、十六烷基三甲基溴化胺、聚乙烯醇、十二烷基硫酸钠和聚丙烯酰胺所制得的氧化锌粉是棒状,而添加了乙酰苯胺和三聚磷酸钠所制得的氧化锌粉是片状。以三聚磷酸钠为表面活性剂,所得的纳米氧化锌在383nm和571nm左右有较强的紫外光致发射峰和黄绿色光致发光峰。     

纳米磷酸锌的可控合成

在氧化锌、磷酸固-液反应体系中,以研磨反应代替搅拌反应,辅助表面活性剂对磷酸锌的颗粒尺寸进行可控合成,考察了研磨介质、磨球比例、球料比、固液比、表面活性剂等工艺条件对磷酸锌粒径分布、形貌及团聚状况的影响,并采用SEM、XRD、粒度分布和TEM对纳米磷酸锌做了表征。结果表明,表面活性剂CTAB浓度为9×10^-4 mol/L、研磨时间为3 h、锆球为研磨介质、球料质量比为150:1、Φ10 mm与Φ6 mm磨球质量比为1:4、转速为200 r/min、固液比[氧化锌和（磷酸+表面活性剂）的质量比]为1:1时,可以制备粒径分布为59~79 nm、平均粒径为68 nm、无团聚的粒状纳米磷酸锌。     

直接沉淀法制备纳米氧化锌工艺研究

提供一种以醋酸锌与碳酸氢铵为原料，添加表面活性剂，直接沉淀法制备纳米氧化锌的新工艺。讨论了反应物浓度和配比、反应温度、反应时间、前驱物碱式碳酸锌热分解温度对纳米氧化锌形成的影响。采用透射电镜（TEM）、X射线衍射（XRD）、热重／差热分析（TG／DTA）等方法对制备的纳米氧化锌进行表征，结果为：制得的氧化锌的平均粒径在20—80nm，晶型为六方晶系。     

在微波辐射作用下制备纳米CeO2及其表面改性研究

本文以Ce(SO4)2·4H2O和NaOH为反应原料,用表面活性剂聚乙二醇(PEG)分散和保护产品,在微波辐射作用下制备了纳米CeO2.采用红外光谱仪、X射线衍射仪和差热热重联用分析仪对所制得的产品进行表征,产品颗粒粒径为24.9 nm.为了扩大所制备的纳米CeO2的应用范围,用表面活性剂月桂酸钠对其进行表面改性研究,结果表明该工艺具有高效、环保、产品分散性好、粒径小和易于推广等优点.     

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.     

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。     

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.