油茶壳微孔活性炭的制备及表征

以油茶壳为原料,经炭化、KOH活化,制备微孔活性炭。考查了活化温度、活化时间和碱炭比对微孔活性炭碘吸附值和产率的影响,并采用正交试验优化了制备条件。研究结果表明：活化温度800℃、活化时间180 min、碱炭质量比3.5：1时,活性炭的碘吸附值达3 221 mg/g,产率51.2%。采用比表面积孔隙分析仪测定了氮气吸附/脱附等温线,计算得BET比表面积为1 755.72 m²/g,平均孔径为2.15 nm,总孔容为0.328 cm³/g,微孔孔容占总孔容的55.8%;SEM分析可见活性炭表面具有大量孔隙结构;FT-IR分析表明活化促进了—CH₃、—OH热解,活性炭中仍保存含氧官能团。     

KOH活化法制备椰壳活性炭研究

以椰壳炭化料为原料,采用KOH活化法制备活性炭,研究了KOH/炭化料的质量比、升温速率、活化温度和活化时间对活性性能的影响。实验结果表明,KOH/炭化料的质量比是该方法制备活性炭的最主要影响因素,较优的工艺参数为:KOH/炭化料的质量比为4∶1、升温速率为5℃/min、活化温度为800℃、活化时间为1 h。同时制备得到了比表面积达到2413 m2/g、微孔容积达到1.02 cm3/g,且以0.9 nm以下微孔为主的椰壳活性炭。     

不同活化法制备的焦化除尘灰基活性炭的性能比较

采用焦化除尘灰为原料,分别用水蒸气和KOH为活化剂制备焦化除尘灰基活性炭,并对所制的活性炭进行碘吸附值、BET比表面积、孔径分布、孔容以及表面形貌测试。实验结果表明,采用KOH活化法制备的活性炭吸附性能强于采用水蒸气活化法制备的活性炭。氢氧化钾活化法制备的活性炭为中孔孔型,BET比表面积达275.51 m2/g。     

废弃辣椒秸秆高比表面积活性炭的制备及表征

以废弃的辣椒秸秆为原料,KOH为活化剂,制备高比表面积活性炭,研究了碱炭比、活化温度、炭化温度及活化时间对活性炭吸附性能的影响。结果表明,活性炭制备的最佳工艺条件为:碱炭比为3∶1,活化温度为700℃,炭化温度为450℃,活化时间为40 min。在此条件下,制得的活性炭碘吸附值2 356.40 mg/g,亚甲基蓝吸附值41.3 mL/0.1 g,BET比表面积为2 432.135 m2/g,Langmuir比表面积高达3 270.478 m2/g,吸附总孔容为2.064 cm3/g,平均孔径为3.246 nm。SEM和XRD观察发现,辣椒秆活性炭呈不定形态,具有丰富和发达的蜂窝状孔隙结构。     

K_2CO_3活化法制备棉纤基活性炭及孔结构分析

以废旧棉纺织品为原材料,K_2CO_3为活化剂,采用化学活化法制备棉纤基活性炭。选取活化温度、浸渍比、浸渍时间和活化时间为影响因子,探讨不同因素对活性炭碘吸附值和得率的影响,通过分析在不同条件下活性炭的比表面积及孔结构,确定棉纤基活性炭的最佳制备条件。结果表明:K_2CO_3活化法制备棉纤基活性炭的最佳条件为活化温度850℃、浸渍比1∶1、浸渍时间24 h、活化时间2 h;在该条件下,活性炭样品比表面积为1 697.38 m2/g,碘吸附值为1 637.47 mg/g,得率为14.15%;样品的中孔和微孔孔容分别为0.56 cm3/g和0.61 cm3/g。废旧棉织物可以制备出性能优良的活性炭,K_2CO_3活化法在优化棉纤基活性炭的制备工艺中是可行的。     

预炭化时间对煤基活性炭孔结构及电化学性能的影响

以太西无烟煤为前驱体,KOH为活化剂制备煤基活性炭,考察了预炭化时间对煤基活性炭孔结构及电化学性能的影响。结果表明,随着炭化时间的增加,活性炭吸附量先增大后减小,活性炭的比表面积、总孔容先增大后减小,中孔孔容逐渐减小;在预炭化温度800℃,炭化时间6 h,KOH与太西无烟煤质量比为2∶1,活化温度800℃的条件下可制备比表面积为1409 m2/g,总孔容为0.5284 cm3/g,中孔率为6.25%的煤基活性炭。电流密度为50 mA/g时,炭化6 h制备活性炭的比电容最大为127 F/g,电流密度增大至2500 mA/g时,比电容为84 F/g,容量保持率达到66.1%,经过1000次循环充放电后,其容量仍保持93.6%。     

KCl模板法制备煤沥青基活性炭及其电化学性能

以煤沥青为前驱体,以KCl为模板剂,采用KOH直接活化法制备了超级电容器用活性炭。研究了KCl添加量对活性炭比表面积、孔径分布及电化学性能的影响。结果表明:适当的KCl添加量有利于改善活性炭的孔径分布,而且有利于提高活性炭的微孔比例,活性炭的微孔比例最高达到81.19%;KCl与沥青、KOH添加比例为1∶1∶4时,所制备的活性炭具有最佳的电化学性能,充放电电流密度为0.5 A/g时,比电容达到220.6 F/g,电流密度增加到5 A/g时,比电容保持率为82.15%。     

不同活化剂对石油焦基活性炭孔结构的影响

以石油焦为原料 ,Na OH,KOH和 Na2 CO3 为活化剂制备活性炭 ,采用氮气吸附考察了不同活化剂对活性炭的比表面积、中孔和微孔孔径分布、孔容积及平均孔径等孔结构的影响 .结果表明 :KOH活化制备的活性炭包含 1 nm的微孔和 4nm的中孔 ,总孔容 0 .648cm3 /g,比表面积大 ;Na OH制备的活性炭以 1 nm的微孔为主 ,占总孔容 ( 0 .1 65 cm3 /g)的 98% ,平均孔径 1 .83nm;Na2 CO3 制备的活性炭以 4nm的中孔为主 ,占总孔容 ( 0 .1 43cm3 /g)的 68.5 % ,平均孔径 3.42 nm,比表面积小 .3种样品的孔径都呈现出多峰分布特征 .KOH和 Na2 CO3 活化制备的活性炭的 N2 吸附脱附曲线属于 型 ,Na OH活化制备的活性炭吸附脱附曲线属于 型 .     

氢氧化钾活化后焦粉的结构变化及其对铅吸附性能的影响

以焦粉为原料,采用KOH活化制备活性炭,通过比表面积及孔径分析仪、X射线粉末衍射仪和X射线光电子能谱仪对焦粉和活性炭的结构和表面化学性质进行分析,并考察了焦粉和活性炭对铅的吸附性能。结果表明:KOH可以活化焦粉制备活性炭,所得活性炭与焦粉相比具有大量的微孔和中孔,比表面积和孔容分别是焦粉比表面积和孔容的7倍和5倍;碳微晶的芳香层面间距变大,芳香微晶的尺寸变小,结晶有序度降低。此外,活性炭表面增加了金属K元素,n(O)∶n(C)由焦粉的10.62%提高到■和C—O—C含氧官能团相对含量增加,■能团相对含量降低。焦粉活化后,破坏了碳的微晶结构,生成大量的孔隙,增加了表面含氧官能团相对含量,为铅提供了更多的吸附点位,使铅的去除率由20%提高到79%。     

球形活性炭的制备及其对低浓度丙酮的吸附

以苯乙烯、二乙烯基苯为原料,采用悬浮聚合法制备了凝胶型聚苯乙烯树脂球,经磺化、炭化、水蒸气活化,得到聚苯乙烯基球形活性炭(PACSs)。通过氮气吸附、二氧化碳吸附对球形活性炭的孔结构进行表征,采用固定床吸附探究其对低浓度丙酮的吸附性能。结果表明,球形活性炭的孔结构可以通过控制活化时间来调控,其比表面积和总孔容均随着活化时间的延长而增加,其中比表面积在789~2 022 m~2/g内可调,而微孔孔容所占比例(V_(micro)/V_t)和比表面积所占比例(S_(micro)/S_(BET))则随活化时间的延长先升高后降低。活化时间为1 h时,球形活性炭对丙酮具有最大吸附量。同时,孔径在0.4~0.5 nm的超微孔孔容是低浓度丙酮气体饱和吸附量的决定因素。     

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。