活性炭电极电容法脱盐工艺和性能的研究

电容法脱盐技术是以直流电为驱动力，利用电化学双电层充电原理脱盐的方法。本文利用恒压充放电方法，对装置的运行工艺，如施加电压，原水浓度和流速等因素对活性炭电极电吸附容量的影响进行了探讨；同时，对比研究了碱金属和碱土金属氯化物在活性炭电极表面的等电势吸附等温线的差异。结果表明，随施加电压提高，可以提高单位质量活性炭对离子的吸附容量，且0．6～1．5V范围内，吸附容量与旖加电压呈线性增加关系。     

活性炭电极电容法脱盐工艺和性能的研究

电容法脱盐技术是以直流电为驱动力,利用电化学双电层充电原理脱盐的方法.本文利用恒压充放电方法,对装置的运行工艺,如施加电压,原水浓度和流速等因素对活性炭电极电吸附容量的影响进行了探讨;同时,对比研究了碱金属和碱土金属氯化物在活性炭电极表面的等电势吸附等温线的差异.结果表明,随施加电压提高,可以提高单位质量活性炭对离子的吸附容量,且0.6～1.5V 范围内,吸附容量与施加电压呈线性增加关系.碱金属和碱土金属离子在活性炭电极表面的平衡吸附容量主要受其水化离子半径影响,即水化离子半径小,所带电荷少的阳离子吸附性能更好,依次为K >Na >Li >Ca2 >Mg2 .     

聚苯乙烯衍生物/碳纳米纤维复合材料的制备与电容去离子研究

将聚丙烯腈(PAN)和聚苯乙烯(PS)经静电纺丝和碳化制备出了碳纳米纤维(CNF),以PS为原料制得的聚苯乙烯磺酸钠(PSS)为亲水修饰剂,经简单混合制备亲水性PSS/CNF复合材料。实验结果表明:PSS已成功修饰于CNF表面,得到的PSS/CNF材料的亲水性得到了大幅改善;将PSS/CNF材料作为电极时,在0.5 A/g的电流密度下,比容量高达199 F/g,具有较好的电化学性能;以一对PSS/CNF电极平行组装成的超级电容器去离子装置,在外加1.4 V电压时,可以达到16.9 mg/g的脱盐量,是由CNF组成的超级电容去离子装置脱盐量的1.5倍。且循环100圈后还能保持80%的脱盐性能,具备优良的循环稳定性。     

高表面活性炭电极的制备及其在双电层电容器中的应用

综述了高表面活性炭电极的原料制备、电极成型及修饰技术的研究进展,论述了双电层电容器电化学性能的影响因素,提出了提高双电层电容器电化学性能的方法,主要包括修饰和改善高表面活性炭的微观结构、改进电极成型工艺技术和电极的预处理方式等.并建议根据实际应用过程中双电层电容器的等效电路和Gouy-Chapman-Stern(GCS)模型理论,计算出高表面活性炭电极表面上的电解质的分布形态,以此作为研究双电层电容器的微观结构和吸附储电机理的突破点,为高表面活性炭电极用于双电层电容器的进一步发展提供理论指导.     

活性炭电极表面掺杂改性研究进展

活性炭作为超级电容器电极材料,具有众多优点,但还存在着能量密度低的特点。电极的能量密度反应了超级电容器的放电能力,为了提高活性炭电极材料的能量密度,增加其比电容是目前研究的重点。本文介绍了表面掺杂O、N、P、B等元素以及其他元素共掺杂改性活性炭,详细的阐述了各元素掺杂对活性炭表面性质及其电化学性能的影响,为提高活性炭电化学性能提供了参考。     

活性炭纤维电极的电容去离子脱盐试验研究

以活性炭纤维为电极材料研制液流式电容去离子模块,考察了电压、进水流量、进水浓度对其脱盐性能的影响。结果表明,活性炭纤维电极用于电容去离子脱盐具有吸附效率高、再生性能好的优点。对活性炭纤维进行载钛改性,改性后的电极单位吸附量提高了31.61%。对于电导率为7.31 mS/cm的电镀反渗透浓水,在21级电容去离子模块串联作用下,离子去除率高达95.21%。处理后的电导率与自来水相近,说明以活性炭纤维为电极的电容去离子技术具有广阔的应用前景。     

活性炭纤维电极的电容去离子脱盐试验研究

以活性炭纤维为电极材料研制液流式电容去离子模块,考察了电压、进水流量、进水浓度对其脱盐性能的影响。结果表明,活性炭纤维电极用于电容去离子脱盐具有吸附效率高、再生性能好的优点。对活性炭纤维进行载钛改性．改性后的电极单位吸附量提高了31．61％。对于电导率为7．31mS／cm的电镀反渗透浓水,在21级电容去离子模块串联作用下．离子去除率高达95．21％。处理后的电导率与自来水相近,说明以活性炭纤维为电极的电容去离子技术具有广阔的应用前景。     

添加松木屑对无灰煤基活性炭结构和电化学性能的影响

以褐煤基无灰煤和松木屑为原料，以KOH为活化剂，制备双电层电容器用活性炭电极材料。采用XRD,FTIR,SEM及低温N₂吸脱附表征活性炭的组成和结构，通过循环伏安测试、恒流充放电测试及交流阻抗测试考察其电化学性能。结果表明：制备时向无灰煤中添加松木屑可以改善活性炭的孔径分布，提高活性炭的电化学性能。当松木屑添加量为30%时，活性炭的电化学性能达到最佳，此时比表面积为2 695 m²/g,比不添加松木屑时增加了44%,且0.5 nm～1.5 nm的有效孔增加了11%,小于0.5 nm的无效孔减少了24%,孔径分布更加合理。以该活性炭作双电层电容器的电极材料，在0.05 A/g的电流密度下比电容达到321 F/g,比以不添加松木屑时制备的活性炭作电极材料时的比电容提高了30%,电荷转移电阻降低了35%,证明添加松木屑可有效改善无灰煤基活性炭的电化学性能。     

针状焦基电容器碳质电极材料的制备及电化学性能研究

以煤系针状焦生焦为原料,KOH为活化剂,制备了用于超级电容器电极材料的活性炭。以3 mol/L KOH为电解液,用三电极电化学系统测试了活性炭的电化学性质;考察了活化剂用量对活性炭电化学性质的影响。研究结果表明：活化过程中,随着碱含量的增加,活性炭的电化学性能逐渐提高。当碳碱比为1∶3时,活性炭的比表面积达到2572.7 m²/g;电流密度为1 A/g时,其质量比电容达到316 F/g。循环5000圈之后,比电容保持在95.7%,库仑效率保持在97.0%。采用两电极系统,进一步考察了活性炭的电化学性能,以1 mol/L Na₂SO₄为电解液,电压窗口拓宽至1.8 V,循环伏安曲线同样展现出良好的矩形,能量密度和功率密度分别为20.8 W·h/kg和230 W/kg。     

超级电容器用活性炭电极材料研究进展

综述了超级电容器及其最常用的电极材料-活性炭材料。介绍了活性炭电极超级电容器的工作原理,总结了物理活化、化学活化以及物理-化学联合活化等制备活性炭电极材料的方法,并指出了各种方法的优点及存在的问题。重点阐述了活性炭材料的比表面积、孔径分布及表面官能团等影响因素对超级电容器电化学性能的影响,最后对活性炭电极材料的未来发展方向进行了展望。     

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。