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1.
在常压及650℃下,以含1%O2的甲烷-氧混合气进料,考察了在CaO,SrO,ZnO,TiO2,CeO2和MnO2膜上外加电流为-90~90mA范围内联合体系的甲烷氧化偶联反应,结果表明,在p型和n型半导体催化膜上,发生NEMCA效应的增强因子有一极值,联合体系中泵氧OCM反应的C2烃选择性低于开路体系中反应的C2烃选择性,根据总反应速率求出了总传递系数及电化学影响效率,电化学影响效率随n型电导率  相似文献   

2.
研究了含LiClO4盐的聚氧化烯(PEO)400与环氧树脂所形成的互穿网络系统的非晶高分子膜的电导率随压力(0~40MPa)的变化。温度由室温至70℃,电导率在5MPa下电导率对压力变化的等温曲线上出现一极大值,超过5MPa以后,电导率随压力的增加而减小。计算了激活体积,从结晶化学原理和离子沿最小能量途径迁移原理并考虑离子传输通道的微观物理图像解释了压力对样品的电导率和激活体积的影响。  相似文献   

3.
研究了含NaClO4的PEO400与环氧树脂所形成的完全无定形的互穿聚合物网络(IPN)固体电解质的电导率与压力和温度的关系.在室温至70℃和压力0—40MPa的范围内,这类IPN的电导率在6MPa左右出现极大值,超过6MPa以后,电导率随压力的增加而减小.计算了在不同压力下的激活体积.与含LiClO4的同类IPN体系进行了比较.从离子偶极作用原理出发对结果进行了讨论.实验表明离子通道畸变受运动离子的大小影响.离子半径越小,对离子通道影响越大,因而电导率改变也大.  相似文献   

4.
在聚丁二酸乙二酯-硫氰化钠(PESC-NaSNC)络合物中了掺入分散第二相ZrO2,而ZrO2的含量及颗粒度对络合物电导率的影响很大。当颗粒度为0.537μm左右时,电导率比较PESC-NaSCN高两个数量级,颗粒度为1.435μm和2.437μm左右时,电导率均比纯PESC-NaSCN低。ZrO2与络合物重量比为0.30时,电导率最大。这种现象可用空间电荷层的高电层层理论的连续沟通模型来解释。  相似文献   

5.
LiAgSO4-Al2O3复合电解质的导电性研究   总被引:6,自引:0,他引:6  
研究了分散第二相α-Al2O3对LiAgSO4的离子导电性的影响,发现LiAgSO4-Al2O3的电导率随a-Al2O3含量的增加而升高,在300-500℃间电导率高于纯LiAgSO4,a-Al2O3含量摩尔比约为40时最高。TG-DTA和XRD分析表明,在高温稳定的体立心LiAgSO4降温后以Ag2SO4的正交β相形式存在,但在H2O存在下,生成Li2SO4.H2O和Ag2SO4.FT-IR分析  相似文献   

6.
用EHMO-CO方法研究了卤代聚苯胺的能带结构及其掺杂导电机理,结果表明,在掺杂态卤代聚苯胺中形成单极化子晶格;取代主要通过改变带宽影响电导率,由掺杂而大幅度地提高了电导率是因为大大缩小了带隙,并进一步证实了外层d轨道的成键作用。  相似文献   

7.
聚环氧乙烷环氧丙烷—盐复合物的结构和导电性   总被引:3,自引:2,他引:3  
齐力  宋永贤 《应用化学》1993,10(5):61-65
制备了室温电导率较高(10^-4S·cm^-1),力学性能较好的环氧乙烷和环氧丙烷共聚物-Li-ClO4复合物薄膜,研究了共聚物组成对结晶及对复合物室温电导率的影响,考察了高氯酸锂浓度对复合物室温电导率的影响以及复合物电导的温度依赖关系,发现复合物中没有结晶配合物,其结晶度随聚合物结构和盐含不同而变化,室温下呈弹性体。  相似文献   

8.
马来酸酐-醋酸乙烯酯交替共聚物以聚乙二醇单醚醇解,得到带有不同长度的聚醚氧侧链的羧酸型梳状聚合物,其碱金属盐在加入适当增塑剂成膜后,可作为聚合物单阳离子导体,其结构以非晶态为主,具有较低的玻璃化转变温度及较好的热稳定性,增塑后的室温电导率最高可达10-5S/cm.研究发现,适当增加侧链的长度有利于提高聚合物膜的离子电导率.此外,还详细探讨了增塑剂、阳离子半径、温度及外加频率等因素对电导率的影响.  相似文献   

9.
环氧乙烷和环氧丙烷共聚物及其LiClO4复合物的热性能   总被引:1,自引:0,他引:1  
齐力  宋永贤 《应用化学》1994,11(2):116-118
用DSC研究了环氧乙烷和环氧丙烷共聚物(EO/PO)及其LiClO_4复合物的组成与热性能的关系,结果表明,结晶熔融热溶随PO的增加而减少,同时,结晶度下降,电导率上升;O/Li=20的试样在2次升温中产生冷结晶;热历史影响聚合物的热性能。  相似文献   

10.
制备了含NaI的环氧树脂-PEO400的IPN高分子固体电解质。X-射线衍射分析表明,这类材料在所研究的范围内呈非晶相。测量了其离子电导率,其最佳室温离子电导率达7.8×10^-5S·cm^-1,与含NaClO4、LiClO4的IPN材料的电导率相差不多,但比NaI-PEO材料的最佳的室温离子电导率高得多。含NaI的IPN薄膜材料具有机械强度高、粘弹性好、透明度好以及易于成膜等优点。  相似文献   

11.
This research is conducted to make solid-state electrolyte based on natural polymers, as an alternative material for energy storage such as battery. Natural polymers as materials of solid state batteries have various benefits, such as unlimited abundance, biodegradable, unleakage, stable form, excellent process, and electrochemical stability, compare to the liquid ones. In this study, a solid state polymer electrolyte based on natural polymer such as chitosan was synthesized by incorporating various ion salts (Li, Cu, Ag) in the polymer matrix. The synthesis of solid-state electrolyte polymer was carried out by casting method to make a thin polymer film. Then the ionic (Li, Cu, Ag) doping with various implant dose will be applied to the thin polymer film matrix by ionic implantation technique. The implanted polymer electrolytes are then characterized their conductivities, micro structures, and crystal structures by high precision LCR, scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD), respectively. The measured of conductivities showed that thin film polymers after implanted with ionic Li, Cu or Ag were increased the conductivity, meanwhile elemental analisys by electron dispersive spectroscopy indicated that ionic implant to chitosan was success. The modification of chitosan polymer to become electrolyte polymer can be concluded.  相似文献   

12.
Low-cost silicon microparticles(SiMP),as a substitute for nanostructured silicon,easily suffer from cracks and fractured during the electrochemical cycle.A novel n-type conductive polymer binder with excellent electronic and ionic conductivities as well as good adhesion,has been successfully designed and applied for high-performance SiMP anodes in lithium-ion batteries to address this problem.Its unique features are attributed to the stro ng electron-withdrawing oxadiazole ring structure with sulfonate polar groups.The combination of rigid and flexible components in the polymer ensures its good mechanical strength and ductility,which is beneficial to suppress the expansion and contraction of SiMP s during the charge/discharge process.By fine-tuning the monomer ratio,the conjugation and sulfonation degrees of the polymer can be precisely controlled to regulate its ionic and electronic conductivities,which has been systematically analyzed with the help of an electrochemical test method,filling in the gap on the conductivity measurement of the polymer in the doping state.The experimental results indicate that the cell with the developed n-type polymer binder and SiMP(~0.5 μm) anodes achieves much better cycling performance than traditional non-conductive binders.It has been considered that the initial capacity of the SiMP anode is controlled by the synergetic effect of ionic and electronic conductivity of the binder,and the capacity retention mainly depends on its electronic conductivity when the ionic conductivity is sufficient.It is worth noting that the fundamental research of this wo rk is also applicable to other battery systems using conductive polymers in order to achieve high energy density,broadening their practical applications.  相似文献   

13.
Ionic conductivities of the polymer electrolytes prepared from the ionomer (poly(methyl methacrylate-co-alkali metal methacrylate)), lithium perchlorate, and ethylene carbonate as a plasticizer, were studied as a function of the ion content and the alkali-metal cation of the ionomer. It was possible to obtain tough films with room-temperature ionic conductivities of ∼ 10-3 S/cm. The maximum ion conductivities of the polymer electrolytes were obtained at the ion content of 5 mol % for both Li and Na ionomer. The effects of the ion content of the ionomer on the ionic conductivities of the polymer electrolytes were mainly interpreted in terms of the characteristics of the ion aggregate formed in the polymer electrolytes. The thermal dependence of the ionic conductivity was shown to be a non-VTF pattern in some of the polymer electrolytes investigated, which is expected to be due to the presence of the ion aggregate. © John Wiley & Sons, Inc.  相似文献   

14.
In nanopore force spectroscopy (NFS) a charged polymer is threaded through a channel of molecular dimensions. When an electric field is applied across the insulating membrane, the ionic current through the nanopore reports on polymer translocation, unzipping, dissociation, and so forth. We present a new model that can be applied in molecular dynamics simulations of NFS. Although simplified, it does reproduce experimental trends and all‐atom simulations. The scaled conductivities in bulk solution are consistent with experimental results for NaCl for a wide range of electrolyte concentrations and temperatures. The dependence of the ionic current through a nanopore on the applied voltage is symmetric and, in the voltage range used in experiments (up to 2 V), linear and in good agreement with experimental data. The thermal stability and geometry of DNA is well represented. The model was applied to simulations of DNA hairpin unzipping in nanopores. The results are in good agreement with all‐atom simulations: the scaled translocation times and unzipping sequence are similar. © 2015 Wiley Periodicals, Inc.  相似文献   

15.
We have prepared two types of one-dimensional ion-conductive polymer films containing ion nanochannels that are both perpendicular and parallel to the film surface. These films have been obtained by photopolymerization of aligned columnar liquid crystals of a fan-shaped imidazolium salt having acrylate groups at the periphery. In the columnar structure, the ionic part self-assembles into the inner part of the column. The column is oriented macroscopically in two directions by different methods: orientation perpendicular to the modified surfaces of glass and indium tin oxide with 3-(aminopropyl)triethoxysilane and orientation parallel to a glass surface by mechanical shearing. Ionic conductivities have been measured for the films with columnar orientation vertical and parallel to the surface. Anisotropic ionic conductivities are observed for the oriented films fixed by photopolymerization. The ionic conductivities parallel to the columnar axis are higher than those perpendicular to the columnar axis because the lipophilic part functions as an ion-insulating part. The film with the columns oriented vertically to the surface shows an anisotropy of ionic conductivities higher than that of the film with the columns aligned parallel to the surface.  相似文献   

16.
A series of all-solid polymer electrolytes were prepared by cross-linking new designed poly(organophosphazene) macromonomers. The ionic conductivities of these all-solid, dimensional steady polymer electrolytes were reported. The temperature dependence of ionic conductivity of the all-solid polymer electrolytes suggested that the ionic transport is correlated with the segmental motion of the polymer. The relationship between lithium salts content and ionic conductivity was discussed and investigated by Infrared spectrum. Furthermore, the polarity of the host materials was thought to be a key to the ionic conductivity of polymer electrolyte. The all-solid polymer electrolytes based on these poly(organophosphazenes) showed ionic conductivity of 10−4 S cm−1 at room temperature.  相似文献   

17.
Response times and voltages for PDLC light shutters   总被引:1,自引:0,他引:1  
The response times and operating voltages of light shutters formed from polymer dispersed liquid crystals (PDLCs) have been studied experimentally and the results compared with calculations based on non-sperhically shaped nematic droplet models. The experiments were performed on light shutters with elongated and uniformly aligned droplets where the relaxation time and voltage response were measured. It is shown that the droplet shape can be a dominant factor, particularly for the relaxation time, and the data are compared with equations derived in terms of the aspect ratio of the droplet l = a/b, where a and b are the lengths of the semi-major and semi-minor axes, respectively, of the elongated droplet. It is further demonstrated that the electric field inside the droplet can be considerably smaller than the applied field, due to the conductivity and dielectric properties of the polymer and liquid crystal materials. These data are used to obtain values for the ratio of the conductivities of the polymer binder and liquid crystal droplet, as well as the anisotropy of the conductivity in the liquid crystal.  相似文献   

18.
离子导电聚合物电解质的研究*   总被引:14,自引:1,他引:13  
本文对离子导电聚合物电解质的发展史、分类、导电机理、研究方法及离子导电聚合物电解质电导率提高的途径进行了综述分析,并讨论了今后工作的发展方向。  相似文献   

19.
We report the fabrication and extensive characterization of solid polymer electrolyte-gated organic field-effect transistors (PEG-FETs) in which a polyethylene oxide (PEO) film containing a dissolved Li salt is used to modulate the hole conductivity of a polymer semiconductor. The large capacitance (approximately 10 microF/cm2) of the solution-processed polymer electrolyte gate dielectric facilitates polymer semiconductor conductivities on the order of 103 S/cm at low gate voltages (<3 V). In PEG-FETs based on regioregular poly(3-hexylthiophene), gate-induced hole densities were 2 x 10(14) charges/cm2 with mobilities >3 cm2/V.s. PEG-FETs fabricated with gate electrodes either aligned or intentionally nonaligned to the channel exhibited dramatically different electrical behavior when tested in vacuum or in air. Large differences in ionic diffusivity can explain the dominance of either electrostatic charging (in vacuum) or bulk electrochemical doping (in air) as the device operational mechanism. The use of a larger anion in the polymer electrolyte, bis(trifluoromethanesulfonyl)imide (TFSI-), yielded transistors that showed clear current saturation and square law behavior in the output characteristics, which also points to electrostatic (field-effect) charging. In addition, negative transconductances were observed using the PEO/LiTFSI electrolyte for all three polymer semiconductors at gate voltages larger than -3 V. Bias stress measurements performed with PEO/LiTFSI-gated bottom contact PEG-FETs showed that polymer semiconductors can sustain high ON currents for greater than 10 min without large losses in conductance. Collectively, the results indicate that PEG-FETs may serve as useful devices for high-current/low-voltage applications and as testbeds for probing electrical transport in polymer semiconductors at high charge density.  相似文献   

20.
Electrolytes based on lithium oligoether sulfate, and dissolved in liquid or polymer solvents, are studied. Their properties in term of ionic conductivities, transference numbers, diffusion coefficients, and electrochemical stabilities are reported. The comparison between NMR and electrochemical data, that is, transference numbers and conductivities, provides important information about the existence of ion pairs and aggregates. A fairly good agreement can be noticed between the highest occupied molecular orbital (HOMO) energies and the stability of the salts towards oxidation in relation with the length of the oligoether tail.  相似文献   

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