改性活性碳纤维对苯胺吸附特性分析

开展了等离子体改性活性碳纤维对苯胺吸附性能的理论和实验研究。通过改变等离子体改性功率和改性时间,探寻最佳改性条件;采用BET、XPS、FTIR、热重测试对改性前后活性碳纤维理化特性进行了表征分析。结果表明,在等离子改性功率为22W,时间为3min时为最佳改性条件;改性后的活性碳纤维对水溶液中苯胺的去除率可达79.3%,去除率提高了8%。微观上等离子体改性使得活性碳纤维表面含氧官能团含量增加,增强对溶液中苯胺的吸附效果。吸附实验结果表明,改性前后活性碳纤维对苯胺的吸附在溶液pH为6时,吸附效果最佳;但达到同一去除率时改性活性碳纤维的速度更快,并且平衡吸附容量也更大。采用准一级和准二级动力学模型对该吸附过程进行描述,其改性前后均用准二级动力学拟合效果更好,表明活性碳纤维结构的特殊性使其对苯胺的吸附以化学吸附为主。活性碳纤维的等离子体改性提高了其对水溶液中苯胺的吸附速度和容量,增强去除效果降低了苯胺对环境的危害。     

活性碳纤维与颗粒活性炭复合炭罐

一种活性碳纤维与颗粒活性炭复合炭罐,在罐体的中部盛装有颗粒活性炭,在罐体的上端有发动机接口和油箱接口,下端有空气口,其特征在于：罐体内颗粒活性炭的上方和下方有活性碳纤维层,在活性碳纤维层的另一侧设置有筛板。颗粒活性炭经无纺布或薄筛板与活性碳纤维层相连,或者颗粒活性炭的上方和下方直接与活性碳纤维相连。该实用新型吸附容量大,吸附速度快,不仅使活性炭罐的体积得以充分利用,而且具有保护环境,节约能源的作用。     

柱状商品活性炭对苯胺的吸附研究

为了研究柱状商品活性炭对苯胺的吸附效果及影响规律,探索了柱状商品活性炭吸附苯胺的影响因素及吸附最佳条件?在单因素试验及正交试验的基础上,对苯胺的脱除率和吸附量进行了单因素方差分析,结果表明吸附影响因素(投炭量、吸附时间、苯胺初始浓度、pH)对脱除率的影响水平强弱次序为:吸附时间苯胺溶液浓度pH活性炭投加量,对吸附量的影响水平强弱次序为:吸附时间苯胺溶液浓度pH活性炭投加量。当活性炭投加量是1 g(即2 g活性炭/mg苯胺),吸附时间180 min,苯胺溶液初始含量10 mg/L,pH为4时脱除率最大能够达到97.21%;当活性炭投加量是0.5 g(即1 g活性炭/mg苯胺),吸附时间180 min,苯胺溶液初始含量10 mg/L,pH为7时吸附量最大能够达到0.9663 mg/g。     

活性炭纤维对钯的吸附性能研究

活性炭纤维是一种新型高效吸附材料,具有比表面积大,微孔发达,孔径分布窄,吸附速度快,吸附能力强等特点.通过活性炭纤维对钯溶液的吸附实验,探讨了静态条件以及动态条件下,溶液的初始浓度,系统的温度,活性炭纤维的质量,吸附时间,不同流速等条件对活性炭纤维吸附性能的影响.研究表明:活性炭纤维对钯有较强的吸附性能,最高吸附率可达...     

活性碳纤维对有机分子吸附性能研究

研究了活性炭纤维吸附亚甲基蓝、中性红、结晶紫溶液的吸附特性,比较了不同孔径大小对不同分子直径染料的吸附情况,考察了p H值与温度对吸附的影响并确定了吸附动力学模型。实验结果表明,温度对活性炭纤维吸附能力影响不大,而酸性环境会导致其吸附能力下降。在相同温度及p H条件下,活性碳纤维对三种染料的吸附能力为中性红亚甲基蓝结晶紫,且随着孔径的减小,其对大分子有机染料的吸附力明显下降;对于相同孔径的ACF,分子体积较小的有机分子吸附速率大于大分子。吸附过程符合拟二阶反应模型。     

活性碳纤维对刚果红的吸附及再生研究

以棉短绒为原料,经磷酸盐浸渍、碳化、活化制备活性碳纤维,将其用于刚果红染料废水的吸附处理,考察了刚果红溶液初始浓度、刚果红溶液pH值、活性碳纤维用量、吸附时间对吸附效果的影响,并研究了活性碳纤维对刚果红的吸附动力学及活性碳纤维的再生利用。结果表明,活性碳纤维对刚果红有较强的吸附性能,当刚果红溶液初始浓度为200mg·L~(-1)、pH值为6、活性碳纤维用量为1.0g、吸附时间为180 min时,活性碳纤维对刚果红的吸附率高达93.53%;活性碳纤维对刚果红的吸附行为符合Langmuir等温吸附模型,吸附动力学模型符合准二级动力学模型;活性碳纤维经过800℃高温煅烧后可再生利用,且吸附效果较好,再生5次的吸附率仍可达到91.28%。     

活性碳纤维吸附法脱蜡降浊点的研究

探讨了活性碳纤维对润滑油基础油脱蜡降浊点的工艺,考察两种不同比表面积的活性碳纤维在不同温度和不同空速条件下对浊点降低效果的影响和穿透量。结果表明,空速1 h-1,温度50℃,比表面积1 800 m2/g的活性碳纤维浊点降低效果最好,下降的总温度可达10℃。当吸附的基础油体积达到脱蜡塔体积的23倍时,活性碳纤维被穿透。SEM、BET等分析结果表明,比表面积1 800 m2/g的活性碳纤维的孔容、孔径比1 000 m2/g的活性碳纤维大,其表面具有更多的活性位点,更有利于蜡烃组分的吸附。通过尿素络合法分析吸附前后基础油的烃类组成情况,正构烷烃的质量分数由20%下降至10%。气相色谱仪分析吸附前后正十二烷与异构十六烷含量的变化证明,活性碳纤维对正构烷烃具有选择性吸附。     

活性碳纤维吸附法脱蜡降浊点的研究

探讨了活性碳纤维对润滑油基础油脱蜡降浊点的工艺,考察两种不同比表面积的活性碳纤维在不同温度和不同空速条件下对浊点降低效果的影响和穿透量。结果表明,空速1 h-1,温度50℃,比表面积1 800 m2/g的活性碳纤维浊点降低效果最好,下降的总温度可达10℃。当吸附的基础油体积达到脱蜡塔体积的23倍时,活性碳纤维被穿透。SEM、BET等分析结果表明,比表面积1 800 m2/g的活性碳纤维的孔容、孔径比1 000 m2/g的活性碳纤维大,其表面具有更多的活性位点,更有利于蜡烃组分的吸附。通过尿素络合法分析吸附前后基础油的烃类组成情况,正构烷烃的质量分数由20%下降至10%。气相色谱仪分析吸附前后正十二烷与异构十六烷含量的变化证明,活性碳纤维对正构烷烃具有选择性吸附。     

吸附苯酚活性炭微波辅助溶液再生效果

分析了p H对颗粒活性炭(GAC)吸附苯酚性能的影响。实验选择质量分数为1%Na OH溶液,采用微波辅助溶液再生的方法,对吸附苯酚的GAC进行再生研究,探讨实验因素对GAC再生效率的影响。实验结果表明:最佳的再生条件为微波功率520 W、再生时间1.5 min、Na OH再生辅助溶液用量10 m L,此时GAC再生效率为95.6%。在最佳再生条件下,经过6次再生后GAC的吸附能力依然很强。     

活性炭吸附水中新型含氮消毒副产物二甲基亚硝胺

二甲基亚硝胺（N-nitrosodimethylamine, NDMA）是水处理领域中颇为关注的强致癌性新兴含氮消毒副产物。该文系统研究了常见水处理材料及各类型改性颗粒炭活性炭（GAC）对NDMA的静态吸附特征。研究发现煤质颗粒活性炭和木质粉末活性炭对NDMA具有较好的吸附效果,活性炭纤维和煤质粉末活性炭次之,而石英砂、粉末沸石和硅藻土等基本不能吸附NDMA;煤质颗粒活性炭和木质粉末活性炭吸附NDMA的等温线可采用Freundlich模型描述,其k值仅分别为1．295和1．462（mg／g）（L／mg）^n,其1／n值分别为0．95和0．68,该结果说明活性炭难于有效吸附水中NDMA;起始溶液pH和不同离子背景条件下,颗粒活性炭的NDMA系统未见明显变化;对吸附效果较好的颗粒活性炭进行酸改性、碱改性和氮气热改性,结果表明三种改性方法均无法有效提高颗粒活性炭吸附NDMA的效果,酸性改性活性炭Freundlich吸附等温线的k值下降为0．5（mg／g）（L／mg）^n,其它两种改性方法较原碳的吸附容量略有降低。总体研究表明,部分类型活性炭对NDMA具有一定的吸附效果,但吸附容量均较低,不同改性方法均难于有效提高GAC吸附NDMA吸附效果,水处理用常规吸附法难于应对水中NDMA污染。     

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。