镁铝水滑石的合成及其在废水脱磷中的应用研究

采用共沉淀法合成了镁铝水滑石,考察了镁铝比、沉淀剂用量、反应时间、搅拌速率、焙烧温度等对镁铝水滑石吸附磷性能的影响。实验结果表明:Mg/Al-LDH对水中的磷具有良好的吸附作用。其最佳制备条件为:Mg/Al摩尔比3:1、沉淀剂用量[16OH~-+CO_3~(2-)]/[6Mg~(2+)+2Al~(3+)]摩尔比1:1、反应时间3 h、搅拌速度300 r×min~(-1)。当吸附剂用量为0.3 g,水中磷的吸附率可达到100%。经过500℃焙烧3 h,吸附剂用量0.1 g时,吸附率比未焙烧的水滑石提高了18%。使用X射线衍射(XRD)、红外光谱(FT-IR)、比表面积及孔径分析仪(BET)等手段对镁铝水滑石的结构进行了表征。并对其吸附动力学进行了研究,其吸附动力学表现为假二级动力学。     

不同制备方法对MgFe氧化物催化吸附SO2性能的影响

用不同的制备方式得到了 3种MgFe复合氧化物和混合物 ,即机械混合的Fe2 O3 +MgO ;以MgO为载体 ,浸渍法制备的Fe2 O3 /MgO ;以MgFe水滑石类为前驱体 ,经焙烧制得MgFeOx.分别测定了 3种材料对SO2 氧化吸附的速率和硫容量 ,发现MgFeOx 脱硫性能最好 ,硫容量达到 1.4gSO2 /g吸附剂 .通过BET、XRD和IR的表征 ,分析了材料脱硫性能好的原因 .主要是高度分散状态的MgFeOx 中Mg和Fe的协同作用 ,Fe起到了催化氧化的作用 ,Mg是吸附中心 ,氧化和吸附的耦合加快了MgFeOx 对SO2 的吸附速率 ,增加了硫容量     

镁铝钡三元水滑石的制备及吸附性能研究

以Al(NO3)3·9H2O、Mg(NO3)2·6H2O、Ba(NO3)2为原料，用共沉淀法制备了Mg/Al/Ba三元水滑石(Mg/Al/Ba-LDHs)，经过傅里叶红外光谱仪和比表面及孔径分析仪进行表征。考察了该水滑石对重金属铬离子(Ⅲ)的吸附行为及干扰离子，优化了浓度、时间、温度、酸度(pH)等因素对Mg/Al/Ba-LDHs吸附性能的影响。结果表明，在最佳浓度13mg/mL、时间150 min、温度30℃、pH=6时吸附容量最大达到400mg/g。     

镁铝钡三元水滑石的制备及吸附性能

以Al(NO_3)_3·9H_2O、Mg(NO_3)_2·6H_2O、Ba(NO_3)_2为原料,用共沉淀法制备了Mg/Al/Ba-三元水滑石,经过傅里叶红外光谱和比表面及孔径分析法进行表征。考察了该水滑石对重金属铬离子(Ⅲ)的吸附行为及干扰离子影响,优化了浓度、时间、温度、酸度(pH)等因素对Mg/Al/Ba-三元水滑石吸附性能的影响。结果表明,在最佳浓度13mg/mL、时间150min、温度30℃、pH=6时吸附容量最大达到400mg/g。     

Mn2+掺杂Mg/Al水滑石强化水中磷酸盐吸附性能

由于磷酸盐过量引起的富营养化对生态系统和人类健康产生的不利影响，已成为迫切需要解决的全球性环境问题。采用共沉淀法制备了Mn²⁺掺杂的Mg/Al/Mn三元类水滑石材料，实现了废水中磷酸盐的有效去除。采用X射线衍射(XRD)技术对Mg/Al/Mn类水滑石的结构进行了表征，并考察了吸附时间、初始磷浓度以及溶液pH值对磷酸盐吸附效果的影响。结果表明：适量掺杂Mn²⁺能增大类水滑石的层间距，有利于磷酸盐的吸附。Mg/Al/Mn类水滑石对磷酸盐的吸附动力学过程符合准二级动力学模型，而吸附等温线适合用Langmuir模型描述。当Mn²⁺占所有金属离子百分比为2.5%时，理论饱和吸附量最大，达到119.7 mg/g,约为Mg/Al水滑石的2倍。此外，Mg/Al/Mn类水滑石还具有宽的pH值适应范围(3～11)。以上结果表明Mg/Al/Mn三元类水滑石是一种有前途的吸附剂，可用于废水中磷酸盐的高效处理。     

磁性类水滑石的制备和吸附水中磷的研究

采用共沉淀制备一系列磁性Mg-Al、Zn-Al、Mg-Fe和Zn-Fe类水滑石磷吸附剂,并研究了磁性类水滑石的组成、摩尔比、pH值、吸附剂用量等对含磷酸盐废水的吸附性能影响。结果表明,磁性类水滑石对磷酸根有良好的吸附效果,磁性类水滑石的金属组成对磷酸根吸附有显著影响,其中Mg/Al摩尔比为2∶1的磁性类水滑石在pH=5～7范围内吸附效果最好,吸附剂最佳投加量0.5 g,最高吸附量达47.1 mg/g。     

镁铝铁复合氧化物脱除低浓度二氧化硫研究

以水滑石为前驱体,制备了一系列铁镁铝复合氧化物,并采用XRD对其结构进行表征。研究这类氧化物脱除低浓度二氧化硫的反应活性。结果表明:含铁水滑石焙烧产物吸附低浓度二氧化硫的性能良好。在大于600℃吸附温度下,具有较好吸附性能。吸附剂本身制备条件对吸附性能影响较明显。负载Fe_2O_3后吸附性能明显提高。氢还原是再生吸附剂的可行方法。     

类水滑石衍生的铁镁铝复合氧化物的制备及与SO2的反应性

以类水滑石为前驱体,制备了一系列铁镁铝复合氧化物,并采用XRD对其结构进行了表征。研究了这类氧化物作为催化剂与SO2反应的活性和机理。结果表明：该材料是由Mg(Fe,A1)O4(少量)、MgO及分散于晶格中的无定型Fe2O3组成,晶粒尺寸微细,Fe2O3组分较为均匀地分散在整个催化剂表面和体相,因此与SO2的反应在相当宽的温度区间(400-700℃)有高活性。含Fe^3 吸附剂上的吸附产物可能存在着类似—Mg—O—SO2—O—Fe—的桥式连接方式。     

Na2CO3/γ-Al2O3吸附剂对SO2吸附性能的研究

用浸渍法制备了 Na2 CO3 /γ- Al2 O3 吸附剂 ,考察了 Na2 CO3 含量、焙烧温度和吸附温度对 Na2 CO3 /γ- Al2 O3 吸附剂 SO2 吸附性能的影响 .结果表明 :Na2 CO3 含量从 4%增加到 2 0 %时 ,穿透时间和硫容在 1 6%时出现峰值 .未经焙烧的吸附剂穿透时间和硫容都比较低 ,较理想的焙烧温度为 30 0℃～ 40 0℃ .吸附温度对 SO2 吸附性能的影响明显 ,在室温下吸附时 ,穿透时间和硫容都较小 ,适宜的吸附温度为 1 2 0℃～ 1 60℃ .     

Mg-Al类水滑石催化大豆油酯交换制备生物柴油

采用共沉淀法制备了不同n(Mg)/n(Al)比的Mg-Al类水滑石,在不同温度下焙烧得到复合氧化物,作为大豆油与甲醇反应制备生物柴油的催化剂。结果表明,未焙烧Mg-Al类水滑石的催化活性较差,而n(Mg)/n(Al)=3的类水滑石在450℃焙烧时具有极高的催化活性。在反应温度65℃,醇/油15,催化剂用量为大豆油质量的2%,反应3 h,生物柴油产率可达97.4%。催化剂回收再用性能良好,重复使用3次,生物柴油收率仍在90%左右。     

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。