CTAB存在下磺基水杨酸掺杂聚苯胺/碳纳米管复合材料的制备与表征

选择十六烷基三甲基溴化铵(CTAB)对碳纳米管进行表面处理,提高了碳纳米管在苯胺溶液中的分散性。在苯胺的盐酸溶液中,以过硫酸铵为氧化剂,磺基水杨酸为掺杂剂,采用化学氧化法制备了聚苯胺/碳纳米管复合材料。用四探针测试仪对产物的电导率进行了测试,结果表明,复合材料的电导率随碳纳米管加入量的增加而增大,当n(碳纳米管)/n(苯胺)=2时,复合材料的电导率为4.613S/cm,是纯苯胺电导率的2.44倍。用扫描电镜(SEM)、透射电镜(TEM)对产物的微观形貌进行了表征,结果表明,聚苯胺包覆在碳纳米管的表面,包覆层的厚度为60～90nm。用紫外光谱(UV-vis)和傅立叶变换红外光谱(FTIR)对产物的结构进行了表征,结果表明,聚苯胺与碳纳米管之间存在较强的相互作用。     

碳纳米管/磺化聚苯胺复合材料的制备

采用原位聚合法制备了碳纳米管/聚苯胺复合材料,然后通过氯磺化及水解处理得到碳纳米管/磺化聚苯胺复合材料,产物在水中具有较好的分散稳定性,为两者的应用开辟了新领域.采用红外光谱(FT-IR),扫描电镜(SEM)对产物进行分析,结果表明,碳纳米管和苯胺质量比为4:1时,聚苯胺在碳纳米管表面的包覆效果最好.碳纳米管与聚苯胺及...     

草酸掺杂磺化聚苯胺/多壁碳纳米管复合材料的制备与性能

聚苯胺(polyaniline,PANI)磺化后,可显著提高水溶加工性,具有重要工业应用价值,目前的关键是如何获得高导电性的磺化聚苯胺(sulfonatedpolyaniline,SPAN)。本文以多壁碳纳米管(MWCNTs)作为导电添加剂,草酸作为掺杂剂,采用溶液中的化学氧化聚合法制得了具有核-壳结构的聚苯胺(PANI)包覆多壁碳纳米管(MWCNT)复合材料后,再对其进行氯磺化,得到了具有良好导电性的SPAN包覆MWCNT复合材料。紫外-可见光谱研究发现,MWCNT与SPAN之间存在着静电相互作用,稳定了SPAN分子链中的共轭作用,增强了共轭长度。性能测试表明该复合材料的电导率可达到4.45S/cm,比相同方法制备的SPAN高出约5个数量级;在水溶液中的溶解度约为1mg/mL,采用过滤的方法获得了一层均匀且光滑的黑色薄膜,表明其具有优异的成膜性。     

聚苯胺尼龙导电织物的制备及其传感性能

采用低温原位聚合法在尼龙织物表面形成一层聚苯胺导电材料，并用场发射扫描电子显微镜和显微拉曼成像光谱仪对其形貌及化学组成进行表征，用万用表和电化学工作站测试其导电性能。结果表明，聚苯胺聚合在尼龙织物的表面，赋予织物较好的导电性，织物电导率为31.62 S/m。聚苯胺尼龙织物的电阻随应变的增大而增大，当应变回复到初始状态时，织物电阻逐渐恢复并接近初始值，在3500次拉伸-回复循环后仍有96.2%的高循环稳定性。作为导电织物，聚苯胺尼龙织物具有良好的传感性能，在0~15%应变范围内可以准确监测人体的关节运动。同时，聚苯胺尼龙导电织物也具有热电性能，织物的塞贝克系数为8.406μV/K，有望作为温差传感器。     

碳纳米管/聚苯胺复合材料的原位合成及其形成机理

用竖式炉流动法,以二茂铁为催化剂,硫为助催化剂,苯为碳源通过催化裂解反应在1100～1200℃制备了直线形多壁碳纳米管,碳纳米管外径为20～50nm,内径10～30nm,长度50～1000μm。在碳纳米管表面原位合成了聚苯胺,制备出碳纳米管/聚苯胺一维纳米复合材料,复合材料的直径为50～60nm。X射线衍射及热重分析表明,原位合成的聚苯胺的结晶程度和热稳定性较高,聚苯胺在碳纳米管表面以枝晶状生长,探讨了聚苯胺在碳纳米管表面的形成机理。     

纤维状双壁碳纳米管／聚苯胺复合材料的表面及孔结构

通过原位化学聚合过程制备了双壁碳纳米管／聚苯胺（double—walled carbon naontube／polyaniline,DwNT／PAn）复合材料。复合材料呈一维纤维状结构,聚苯胺被均匀包覆在碳管外部。根据低温氮吸附实验结果,复合材料的吸附等温线与双壁碳纳米管相似,仍为多步吸附过程,但由于聚苯胺包覆在碳纳米管外部和端口,导致其表面所含的微孔消失,小中孔含量明显降低。     

水性共价连接型聚苯胺/碳纳米管复合材料的制备及电学性能

首先将改性碳纳米管经原位聚合制备得到了共价连接型聚苯胺/碳纳米管复合物;然后,通过水性掺杂的方法,获得水溶性、导电性优良的聚苯胺/碳纳米管复合材料。透射电子显微镜表明,聚苯胺/碳纳米管复合物的尺寸比纯碳纳米管明显增加;通过UV-vis光谱证实了CNT和PANI之间存在着强烈的相互作用。复合材料的电导率高达4.8×10~(-3)S/cm,比纯聚苯胺的电导率提高了一倍,并显示出优良的水溶性。     

碳纳米管/聚苯胺复合材料分散性和界面特点

利用原位复合工艺,在碳纳米管与聚苯胺复合过程中进行苯胺的原位聚合获得了碳纳米管/聚苯胺复合材料.利用透射电子显微镜对复合材料中的碳纳米管的分散性和碳纳米管/聚苯胺界面进行了分析及检测.结果表明苯胺能够很好的在碳纳米管上形核长大,并且能够完全包覆和缠绕在碳纳米管上.这种工艺有利于碳纳米管很好地分散在聚苯胺基体中.     

纳米铜/碳纳米管对聚苯胺电导率的影响

聚苯胺是制备电极材料的主要原料,碳纳米管和纳米铜的掺杂能提高其电导率和比电容值。采用原位聚合法以过硫酸铵为氧化剂,制备出以纳米铜/碳纳米管为核,以聚苯胺为壳的具有核-壳结构的聚苯胺/纳米铜/碳纳米管复合材料,通过对比不同质量分数的纳米铜/碳纳米管掺杂的聚苯胺循环伏安测试结果分析可知,当纳米铜/碳纳米管占三元聚合物的质量分数为15%时,聚苯胺/纳米铜/碳纳米管复合材料的比电容值最高,测试结果为2102.57F·g-1。     

聚苯胺包覆玻璃鳞片复合物的制备与表征

采用化学聚合和乳液聚合两种方法制备聚苯胺包覆玻璃鳞片复合物。通过XRD、红外光谱、SEM、表面接触角测试、电导率测试、EIS等手段对复合材料的结构、形貌和性能进行了表征。结果表明:不同方法制备的聚苯胺包覆玻璃鳞片复合材料在结构、微观形貌和电导率上有较大差别,其中乳液法制备的复合材料,聚苯胺在玻璃鳞片载体上能够生长成较长的纤维,具有较高的结晶度,电导率高达2.281 S/cm。最后以之为导电填料,制备环氧防腐导电涂料,经研究表明其具有优异的导静电、防腐性能和机械性能。     

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.     

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。     

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.