十二烷基苯磺酸掺杂聚苯胺的性能研究

用十二烷基苯磺酸 (DBSA)对本征态聚苯胺 (PAn)进行掺杂 ,得到溶解性、成膜性和光电性能俱佳的掺杂态聚苯胺。红外光谱研究表明 :DBSA掺杂PAn的吸收峰都向低频方向移动。探讨DBSA浓度、掺杂温度和时间以及洗涤滤液pH值对聚苯胺电导率的影响。结果表明 :当c(DBSA) =1 0mol/L ,T =32 3K ,t=8h ,洗涤滤液 pH =3时 ,聚苯胺的电导率为 0 90 9S/cm。紫外 -可见吸收光谱表明 ,掺杂态聚苯胺的吸收峰变宽而且发生红移。X射线衍射在 2θ =8 86°,1 7 7° ,2 1 4°和 2 6 7°处出现 4个较强的低角度衍射峰 ,表明DBSA掺杂的聚苯胺具有较强的结晶性能。     

磺酸掺杂煤基聚苯胺/HDPE导电复合材料的制备

采用热掺杂法制得十二烷基苯磺酸 (DBSA)掺杂态煤基聚苯胺 (CBP) ,并采用熔融共混工艺 ,制备出HDPE/CBP DBSA导电复合材料 ,研究了掺杂时间和掺杂温度对CBP电导率以及CBP DBSA用量对HDPE/CBP DBSA复合材料电阻率的影响。结果表明 :当m (DBSA)∶m (CBP) =1 6,70℃下退火 2h时 ,CBP DBSA的电导率可达0 179S/cm ;红外光谱说明DBSA对CBP起到了较好的掺杂作用。当CBP DBSA的质量分数为 13 %时 ,复合材料的体积电阻率达到 2 9× 10 7Ω·cm ,同时具有较好的力学性能     

磁场环境下氧化剂和掺杂剂浓度对聚苯胺性能的影响

在不同磁场强度下,用过硫酸铵(APS)为氧化剂,磺基水杨酸(SSA)为掺杂剂合成导电聚苯胺(PAn),通过对PAn掺杂率的计算和电导率的测定,研究了氧化剂和掺杂剂浓度对PAn性能的影响。采用红外光谱、X射线衍射、粒径分析等研究了制备的PAn性能与结构。实验结果表明磁场对苯胺聚合的影响是正向的,氧化与掺杂条件的变化是影响电导率的重要因素。     

丙烯酸酯三元共聚物酸掺杂改性聚苯胺的研究

选择丙烯酸 (AA)、丙烯酸丁酯 (BA)和甲基丙烯酸甲酯 (MMA)三元共聚物对聚苯胺 (PAn)进行改性 ,研究了BA的用量和引发剂浓度对PAn导电率的影响 ,对样品进行DSC、FTIR和SEM测试。结果表明 ,丙烯酸酯三元共聚物酸对PAn有良好的掺杂改性作用 ,当共聚单体 (AA -BA -MMA)组成为 10∶45∶45 (质量比 ) ,引发剂浓度为0 0 5 48mol·L-1时 ,可制得电导率达 1 42 1S·cm-1的导电PAn。     

掺杂态聚苯胺的乳液聚合及其与环氧树脂所制涂层的耐蚀性

以十二烷基苯磺酸钠(SDBS)为乳化剂,采用乳液聚合法制备了盐酸或磷酸与十二烷基苯磺酸(DBSA)共掺杂的聚苯胺[(HCl+DBSA)-PANI或(H_3PO_4+DBSA)-PANI]。用扫描电镜、傅里叶变换红外光谱仪、X射线衍射仪和四探针电导率测试仪表征了掺杂聚苯胺的形貌、结构和电导率。将添加了掺杂态聚苯胺的E44环氧树脂刷涂在Q235低碳钢表面得到复合涂层(PANI/EP),并通过电化学阻抗谱和浸泡试验考察了它们在3.5%NaCl溶液中的耐蚀性。两种共掺杂态聚苯胺都呈束状结构,(HCl+DBSA)-PANI的结构更均一。添加PANI可以明显提高环氧涂层对碳钢的防腐作用,其中(HCl+DBSA)-PANI的效果更好。     

导电聚苯胺/OMMT纳米复合材料的研究

以十二烷基苯磺酸(DBSA)为掺杂剂和乳化剂,过硫酸铵(APS)为引发剂,采用乳液插层聚合方法制备了导电聚苯胺包覆有机蒙脱土(OMMT)纳米复合材料。探讨OMMT、APS和DBSA用量对复合材料电导率的影响。结果表明,在苯胺、APS、DBSA三者摩尔比为1：1：1．5时,苯胺与OMMT质量比为1：3.5时,复合材料的电寻率最高可达0．0571S／cm。用X射线衍射和傅立叶变换红外光谱对复合材料进行了表征。结果表明,聚苯胺已插层到OMMT层间,且聚苯胺在受限的纳米空间只能以有限层分子存在,很可能是伸展链构象。     

磺酸原位掺杂煤基聚苯胺的制备及性能研究

采用化学原位乳液聚合法合成十二烷基苯磺酸(DBSA)掺杂煤基聚苯胺导电复合材料(CBP-DBSA)。研究了反应体系中煤粉用量，聚合温度，聚合时间、苯胺单体浓度及过硫酸铵、DBSA用量对复合材料电导率的影响，确定了较佳的反应条件．同时考察了热处理温度对CBP-DBSA电导率的影响，并且通过FTIR、TGA测试手段对复合材料的结构、热稳定性进行了表征和分析。     

对甲苯磺酸掺杂聚苯胺材料的导电性能及其机理研究

通过再掺杂法制备了对甲苯磺酸（TSA）掺杂的导电聚苯胺（PANI）,探究掺杂时间及对甲苯磺酸水溶液的浓度对PANI的电导率和结构的影响,通过四探针法和傅里叶变换红外光谱仪(FTIR)分析表征了掺杂态PANI的电导率和结构,并探究掺杂时间对掺杂态PANI导电性能影响的机理,还利用热重分析仪(TG)探究TSA对PANI热稳定性的影响。结果表明,掺杂时间为12 h、TSA水溶液浓度为05 mol/L所制得的掺杂态PANI具有最好的电导率。     

不同质子酸掺杂对聚苯胺合成与性能的影响

由化学氧化法制得的聚苯胺(PANI)被不同质子酸掺杂。研究盐酸(HCl)、硫酸(H2SO4)、樟脑磺酸(CSA)和十二烷基苯磺酸(DBSA)掺杂对PANI产率、溶解性以及电导率的影响。研究发现,HCl掺杂的PANI电导率为0.263 4 S/cm、产率可达到78.83%。还讨论不同HCl浓度和不同过硫酸铵/苯胺(APS/An)的物质的量比对HCl掺杂PANI产率和电导率的影响,当HCl的浓度达到1.2 mol/L、APS/An物质的量比为0.6时,PANI的电导率和产率均为最大值。     

樟脑磺酸掺杂聚苯胺的合成及性能研究

采用溶液聚合法,用樟脑磺酸(CSA)在间甲酚(m-c)与三氯甲烷(ch)的混合溶剂中对聚苯胺进行掺杂,掺杂能够使聚苯胺在保持较好溶解性的同时,提高其电导率。当PANI/CSA(mol/mol)=1/50时,制备出了电导率高达400 S.cm-1的PANI-CSA自支撑膜。采用四探针法测量了掺杂态聚苯胺的电导率,并用红外光谱(FT-IR)和热失重(TG)等方法表征了樟脑磺酸和盐酸掺杂的聚苯胺的结构和形态。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.     

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.