聚多巴胺包覆Fe_3O_4纳米粒子异相芬顿催化降解亚甲基蓝

采用共沉淀法制备了磁性Fe_3O_4纳米粒子(Fe_3O_4 NPs),通过多巴胺(DA)原位氧化聚合的方式,将聚多巴胺(PDA)引入到Fe_3O_4NPs表面,制备了PDA包覆Fe_3O_4纳米粒子(Fe_3O_4@PDA NPs)。通过TEM、XRD、FTIR、XPS对粒子的形貌、结构及组成进行了表征。随后将其作为异相芬顿(Fenton)催化剂用于催化亚甲基蓝(MB)的氧化降解,对该催化剂的催化活性及稳定性进行了考察,探讨了催化反应的机理。结果表明:Fe_3O_4NPs作为催化剂时,,MB 2 h脱除率为26%,而Fe_3O_4@PDA NPs作为催化剂时,30 min,MB的脱除率为99%。具有酚醌单元的PDA可促进Fe~(3+)与Fe~(2+)间的循环,使得Fe_3O_4@PDA NPs较之Fe_3O_4NPs具有更强的催化活性。此外,Fe_3O_4@PDA NPs稳定性良好,可实现2次回收再利用,对活性降低的Fe_3O_4@PDA NPs用NaBH_4处理后,仍具有催化降解MB反应的能力。     

中空多孔磁性Fe3O4/纤维素/海泡石微球异相Fenton催化降解亚甲基蓝

为开发一种高效可循环利用的磁性生物质基催化剂，以微晶纤维素和纳米Fe3O4为原料，采用包埋法制得Fe3O4/纤维素（Fe3O4/MCC）溶液，将海泡石（SEP）掺入至Fe3O4/MCC中，制得磁性纤维素/海泡石复合微球（Fe3O4/MCC/SEP）。通过SEM、FTIR、VSM等对磁性微球的形貌、化学结构及磁性能进行了表征，探讨了微球作为芬顿催化剂对亚甲基蓝（MB）染料的降解效果及机理。结果表明，Fe3O4/MCC/SEP微球呈现出优异的中空多孔结构和超顺磁性。当MB浓度为10 mg/L、pH为3、Fe3O4/MCC/SEP的投入量为0.02 g，H2O2用量为5 mL时，反应240 min对MB的Fenton催化降解率高达99%。此外，经过5次循环利用后，对MB的降解率仍达83%。     

非均相 Fenton催化剂Fe3O4降解亚甲基蓝

采用水热法合成磁性Fe3O4纳米微球,将其作为催化剂与H2O2组成非均相Fenton体系降解亚甲基蓝（MB）,并对Fe3O4纳米颗粒进行了TEM、XRD表征。对初始pH值、H2O2投加量、Fe3O4投加量等条件进行了试验,考察了催化剂的重复利用性能。结果表明：pH值为3、H2O2浓度为0.4 mL/L、催化剂投加量为1.2 g/L、反应温度T=30 ℃、振荡速度为150 r/min时降解效果最好,反应2 h后MB（150 mg/L）降解率为99.6%,催化剂重复利用3次降解效果仍良好。     

前躯体法制备四氧化三铁及其催化性能（急）

以钛白副产品FeSO4为原料，采用前躯体法制备了Fe3O4（记为Fe3O4-PR），并将其作为催化剂催化H2O2降解活性艳红X-3B。考察了pH、H2O2投加量、Fe3O4-PR投加量等对该催化降解反应的影响及Fe3O4-PR催化活性及稳定性。最后对该催化降解反应机理进行了初步探究。XRD、FT-IR、SEM、粒径分析等结果表明，采用前躯体法可成功制备出平均粒径为410nm的多面立体结构Fe3O4。在pH=3、H2O2投加量为3 mM及Fe3O4-PR投加量为1g/L的条件下，活性艳红X-3B的降解率可达97%，TOC去除率为47%。Fe3O4-PR不仅具有良好的稳定性，且催化活性优于传统化学共沉淀法制备的Fe3O4（记为Fe3O4-CO）。机理探究表明催化降解反应是在催化剂表面的活性位点发生，降解过程存在氧化还原循环，?OH是主要活性物质。     

Fe2O3/CNTs纳米粒子的制备及其对高氯酸铵燃速的催化作用

采用液相沉淀法制备沉积于碳纳米管（CNTs）表面的Fe2O3复合纳米催化剂,用透射电子显微镜（TEM）和光电子能谱（XPS）对制备的Fe2O3／CNTs复合纳米催化剂进行表征,研究了Fe2O3／CNTs复合纳米催化剂对高氯酸铵（AP）燃烧的催化性能。结果表明,纳米级Fe2O3颗粒均匀包覆在CNTs表面,Fe2O3／CNTs复合纳米催化剂能明显降低AP的分解温度,提高AP单元推进剂的燃速;Fe2O3／CNTs复合纳米催化剂对AP的催化活性明显优于纳米Fe2O3、纳米Fe2O3和CNTs的简单混合催化剂。     

磁性纳米负载金属催化剂的制备及其在甲苯催化氢化反应中的性能

通过化学共沉淀法制备了Fe3O4,以硅酸钠、铝酸钠为原料,碳分法原位对其进行表面包覆,制备出具有核壳结构的SiO2/Fe3O4及Al2O3/SiO2/Fe3O4复合磁性纳米粒子。利用XRD、SEM、FTIR以及VSM技术对其进行了表征。将所制备的这两种磁性载体分别负载金属Ru及Ru-Co催化剂,以甲苯为底物考察了负载催化剂的组成与催化加氢活性的关系。结果表明,以SiO2/Fe3O4为载体负载的催化剂具有很好的催化活性,循环使用6次后活性未下降;以Al2O3/SiO2/Fe3O4为载体所负载的催化剂,起始催化活性较高,循环过程中活性略微降低。双金属Ru-Co催化剂的催化性能与其形成的结构及组成密切相关,催化活性为RushellCocoreRu-CoCoshellRucore,Ru/Co的摩尔比为1∶5的RushellCocore/PVP/SiO2/Fe3O4催化剂对甲苯有较高的催化活性,催化剂的转化频率可达16656,高于相同条件下的单金属Ru催化剂的转化频率(9828)。     

纳米四氧化三铁降解亚甲基蓝的研究

在浸没循环撞击流反应器中通过共沉淀法,以氨水为沉淀剂,以FeCl3.6H2O和FeSO4.7H2O为原料制备了磁性纳米Fe3O4粒子。采用XRD、TEM等多种方法对制得的纳米粒子的结构和性能进行了表征,并研究了磁性纳米Fe3O4粒子对亚甲基蓝的降解作用。结果表明,纳米Fe3O4粒子具有相对较小的粒径;当溶液pH值为4.2、H2O2加入量为2 mL.L-1时,用0.9 g.L-1的Fe3O4悬浊液对10 mg.L-1的亚甲基蓝溶液进行降解,5 min内亚甲基蓝的降解率可达96.5%。     

微乳液法制备核壳型磁性Eu^3＋-Fe3O4/TiO2纳米复合粒子

用反相微乳液法制备了TiO2纳米粒子、Eu3 掺杂的TiO2纳米粒子及以Fe3o4为核以TiO2为包覆层的核壳型磁性复合纳米粒子,用电镜和X射线衍射研究了样品的形貌和晶体结构,并以甲基橙为目标降解物,研究了不同催化剂的光催化活性.结果表明,Eu3 的掺杂可以提高TiO2光催化剂的活性,核壳型磁性Eu3 -F3O4/TiO2纳米复合粒子能够回收重复利用,保持催化活性.     

聚乳酸/聚多巴胺复合材料的制备及性能研究

聚乳酸(PLA)被认为是一种无毒、生物相容性优异的生物可降解材料,但其降解周期长、缺乏功能性而限制了其更广的应用。为改善聚乳酸(PLA)的各项性能,选用聚多巴胺纳米粒子(PDA NPs)作为纳米填料,通过溶液浇铸的方法制备了聚乳酸/聚多巴胺(PLA/PDA NPs)复合材料。结果表明,所制备的PDA NPs呈规则、均一的球形结构,且可通过改变介质pH调控粒径在140～550 nm;PDA NPs的加入可降低复合材料的冷结晶温度(T_c)和结晶度(X_c);但却能显著提升复合材料的降解速率,且其降解速率先较平缓后明显加快,最终降解20 d后降解率达到95.3%,比纯PLA加快了1倍。此外,PLA/PDA NPs复合材料被发现还具有紫外屏蔽性能,复合材料对UVA和UVB的屏蔽率分别高达65.98%和71.49%,是纯PLA的紫外屏蔽性能的2倍。     

聚乳酸/聚多巴胺复合材料的制备及性能研究

聚乳酸(PLA)被认为是一种无毒、生物相容性优异的生物可降解材料,但其降解周期长、缺乏功能性而限制了其更广的应用。为改善聚乳酸(PLA)的各项性能,选用聚多巴胺纳米粒子(PDA NPs)作为纳米填料,通过溶液浇铸的方法制备了聚乳酸/聚多巴胺(PLA/PDA NPs)复合材料。结果表明,所制备的PDA NPs呈规则、均一的球形结构,且可通过改变介质pH调控粒径在140～550 nm;PDA NPs的加入可降低复合材料的冷结晶温度(T_c)和结晶度(X_c);但却能显著提升复合材料的降解速率,且其降解速率先较平缓后明显加快,最终降解20 d后降解率达到95.3%,比纯PLA加快了1倍。此外,PLA/PDA NPs复合材料被发现还具有紫外屏蔽性能,复合材料对UVA和UVB的屏蔽率分别高达65.98%和71.49%,是纯PLA的紫外屏蔽性能的2倍。     

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。