共查询到20条相似文献,搜索用时 62 毫秒
1.
以偏氟乙烯-六氟丙烯共聚物〔P(VdF-HFP)〕、LiClO4/碳酸二甲酯(DMC)/碳酸乙烯酯(EC)或LiPF6/EC/DMC/碳酸二乙酯(DEC)和纳米SiO2为原料,用自然挥发法和相转移法制成聚合物电解质膜。测试结果表明:对LiClO4/DMC/EC体系,c(LiClO4)=1mol/L,w(SiO2)=7%时,室温(21℃)电导率达最大值2 81mS/cm,72℃时达9 6mS/cm;对LiPF6/EC/DMC/DEC体系,c(LiPF6)=1mol/L,m〔P(VdF-HFP)〕∶m(SiO2)=3∶2时,室温电导率为3 68mS/cm,72℃时达13 8mS/cm。扫描电镜(SEM)和X射线衍射分析(XRD)结果表明,电解质膜为非晶态的多孔结构,纳米SiO2粉末掺入可使微孔的数目明显增多,孔隙率增加,孔分布更均匀;傅里叶红外光谱(FTIR)结果显示,P(VdF-HFP)、增塑剂与LiClO4间存在相互作用。 相似文献
2.
《化学推进剂与高分子材料》2017,(6)
以聚乙二醇(PEG)、有机硅氧烷(OFX)、异佛尔酮二异氰酸酯(IPDI)为主要原料,制备了一系列水性聚氨酯,并与双(三氟甲基磺酰)亚胺锂(Li TFSI)复合,得到一系列全固态聚合物薄膜。通过拉伸性能测试、红外光谱、热重分析和电导率测试等研究了其结构与性能的关系。将制备的聚合物电解质膜用于全固态锂离子电池的组装,测试了电池的性能。结果表明:适量引入有机硅氧烷可改善聚合物电解质膜的力学性能和电化学性能;当PEG与有机硅氧烷质量比为3:1时聚合物电解质膜的综合性能最佳,80℃时电导率为6.24×10~(–4)S/cm;以磷酸铁锂为正极制备的全固态锂离子电池在0.2C电流80℃时放出131 mA·h/g的比容量。 相似文献
3.
以PEO为基质,复配少量纳米无机填料及低分子乙氧化物,制备出了新型的固态纳米复合聚合物电解质膜,利用交流阻抗法测试了聚合物电解质的离子电导率,对离子导电性能进行了研究。采用CPE元件的模拟电路具有很好的适用性。结果表明当低分子乙氧化物的加入量超过80%时电解质膜的电导率大幅提高,并且PEGDME优于PEG300。电导率在LiPF6加量在O:Li为8:1时达到最大,随着LiClO4加量的增加持续增加,随无机盐加量增加电解质膜的成膜性能变差。用多微孔高比表面的纳米SiO2粒子复合有利于改善聚合物的电导率。聚合物电解质离子电导率对温度的依赖关系符合Arrhenius方程。 相似文献
4.
以PVDF-HFP为基体聚合物,制备了一系列凝胶聚合物固体电解质膜,其中有机极性介质为碳酸丙烯酯(PC),电解质盐为LiClO4。通过红外光谱分析、差示扫描量热分析、复阻抗分析等手段对凝胶聚合物固体电解质的结构与离子导电性能进行了研究。结果表明,PC与阳离子之间存在较强的络合作用,PC对基体聚合物有很强的增塑作用。锂盐和PC含量对材料的离子导电性能有较大的影响。随着锂盐和PC含量的增加,材料的离子电导率呈上升趋势。 相似文献
5.
6.
《应用化工》2022,(3)
以聚偏氟乙烯-六氟丙烯(PVDF-HFP)为聚合物基体,制备了含离子液体1-甲基-3-乙基咪唑六氟磷酸盐(EMIPF_6)和1-甲基-3-乙基咪唑二(三氟甲基磺酰)亚胺盐(EMITFSI)的凝胶聚合物电解质,测试了电解质的电导率和阳离子迁移数,并基于自由体积理论的观点对电解质的导电行为进行了研究。结果表明,EMIPF_6-PVDF-HFP与EMITFSI-PVDF-HFP两种离子液体凝胶聚合物电解质,聚合物的分子链段运动对导电离子的迁移影响微小;logσ与1/T呈线性关系,上述两种电解质的导电行为服从阿伦尼乌斯方程,电解质的电导率主要靠自由离子的迁移;离子液体EMIPF_6、EMITFSI的加入促进了Li+的自由移动,显著提高了电解质的锂离子电导率。 相似文献
7.
以甲基丙烯酸甲酯(MMA)和1-乙烯基-3-丁基咪唑溴盐(VBIMBr)为单体,通过自由基溶液聚合制备了无规共聚物聚(甲基丙烯酸甲酯-1-乙烯基-3-丁基咪唑溴盐)[P(MMA-VBIMBr)],并以此聚合物为基体,离子液体1-丁基-3-甲基咪唑四氟硼酸盐(BMIMBF4)为增塑剂,制备了BMIMBF4/P(MMA-VBIMBr)凝胶型离子液体聚合物电解质,采用红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)、热重分析(TG)和电化学交流阻抗(EIS)等方法对聚合物和聚合物电解质的性质进行了研究。结果表明,聚合物电解质膜具有优良的热稳定性和机械强度;当BMIMBF4/P(MMA-VBIMBr)质量配比为2时,离子电导率高达2.77×10-3S/cm(20℃),且离子电导率随着温度的升高而迅速增加,电导率-温度曲线符合Arrhenius方程。 相似文献
8.
9.
一种新型聚合物电解质中离子传递及界面性质研究 总被引:2,自引:0,他引:2
合成了聚(甲基丙烯酸甲酯-丙烯腈-甲基丙烯酸锂)(简记为PMAML)聚合物基质材料,以PMAML和聚偏氟 乙烯混合物为基质制备了新型复合聚合物电解质,其中增塑剂为碳酸乙烯酯和碳酸二甲酯,锂盐是LiBF4。用刮刀 在玻璃板上涂膜得到取合物膜,把聚合物基质膜在电解质溶液中浸渍后成为聚合物电解质膜。采用限制扩散方法测 试了电解质中离子的扩散系数,由稳态极化法测得了迁移数。所制聚合物电解质中锂离子的扩散系数和迁移数分别为 2.67×10-7cm2·s-1和0.53。通过交流阻抗技术研究了聚合物电解质与电极间界面性质,Li/GPE/Li的界面阻抗随放置 时间延长而增大,Li/GPE/MPCF的界面阻抗随电极的电位降低而减小。组装了聚合物电解质锂离子电池,测试结果表 明,该聚合物电解质具有较好的离子传输性质和电化学性能,能用作锂离子电池的电解质。 相似文献
10.
聚合物电解质的离子电导率是电解质的一个重要参数 ,与聚合物电解质中的非晶态的存在有很大的关系。在本文中 ,以X射线衍射 (XRD)、差热分析 (DTA)和交流阻抗 (Acimpedance)为研究手段 ,研究了快冷对聚合物电解质的晶型转变和对聚合物电解质室温离子电导率的影响。在快速冷却的条件下 ,质量比为1∶1的PEO/LiClO4聚合物电解质的室温离子电导率可达 1 6 1x 10 -7S/cm ,比慢冷处理的相同体系的室温离子电导率提高了 1个数量级。实验证明 ,快速冷却可破坏聚合物的结晶性 ,提高聚合物电解质的离子电导率。 相似文献
11.
12.
M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
13.
14.
15.
16.
Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
17.
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. 相似文献
18.
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. 相似文献
19.
中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
20.
中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献