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1.
采用聚氧化乙烯(PEO)、丁二腈和高氯酸锂(LiClO4)的复合电解质体系, 制备了一系列不同配比的PEO/SN/LiClO4复合电解质, 对其室温电性能和相态结构进行了表征, 并探讨了相态结构对室温电导率的影响. 相似文献
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Noor Hidaya Abdul Nasir Chin Han Chan Hans-Werner Kammer Lai Har Sim Muhd Zu Azahan Yahya 《Macromolecular Symposia》2010,290(1):46-55
Summary: Solution casting technique served to prepare solid solutions of lithium perchlorate and poly(ethylene oxide) (PEO) having different molecular masses. Salt concentrations of solutions were varied between around 2 and 13 wt%. Crystallinity and melting point depression served to determine composition and content of amorphous phase as well as thermodynamic behavior of the solutions. Conductivity as a function of salt concentration in the amorphous phase follows a power law at constant temperature (30 °C). It results that both exponent and mobility of charge carriers increase with ascending molecular mass of PEO. The mobility follows an increase with molecular mass proportional to M2.8 indicating dependence of mobility on interstitial volume between chain molecules. Deviation of solution from perfect behavior can be evaluated by melting point depression. Accordingly, increase in conductivity is preferably related to approach to perfect solution behavior. Determination of dielectric function allows some conclusion about ion pair formation in the systems under discussion. It turns out that probability of ion pair formation decreases with increasing molecular mass of PEO in agreement with thermodynamic behavior of the solutions. 相似文献
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某些聚合物经特殊加工可制成具有半导体、导体,甚至超导体性质的材料。最近高分子固体电解质材料引起科学家们极大的兴趣和重视,其研究主要集中在聚醚体系,对聚酯研究甚少。本文对聚丁二酸丁二醇酯体系作了研究。 相似文献
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首次采用新型有机硅聚合物——侧链含一半硅氢键的羟基封端聚二硅氧烷(PSEMH)与聚氧乙烯醚(PEO)作为基质, 通过溶液浇铸法制备了PEO-PSEMH-LiClO4全固态共混聚合物电解质膜. 交流阻抗谱实验测定结果表明PSEMH与PEO共混作为聚合物电解质的基质可以显著提高共混聚合物电解质的离子电导率. PSEMH含量为25%, O/Li+为12∶1时, 共混聚合物电解质具有最大离子电导率2.7×10-5 S•cm-1 (28 ℃). PSEMH的引入一方面可以显著地抑制PEO的结晶性能, 另一方面PSEMH分子链节中的二硅醚氧原子与Li+间具有配位作用, 且参与了共混聚合物电解质锂离子迁移运动. 相似文献
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Suneyana Rawat Pramod K. Singh Shri Prakash Pandey Ram Chandra Singh 《Macromolecular Symposia》2024,413(1):2300050
Future demands for energy shortages have prompted a lot of effort to be put into finding alternatives. The use of renewable energies as a revolutionary energy source has gained acceptance. Due to their high flexibility and the interaction between the electrode and the electrolyte, solid polymer electrolytes are employed as a favorable electrolyte for application of electrochemical devices to storage renewable energy. As these are easy in synthesis, have much lower mass density, shows high mechanical stability, also have low binding energy with salts, and high mobility of charge carriers, polyethylene Oxide (PEO) based electrolyte has attracted a lot of interest. Configuration rectification combining PEO with ionic liquids has been introduced to enhance the low ionic conductivity and poor thermodynamic stability of the PEO materials in high-voltage devices at ambient temperature. This configuration modification can successfully validate the applications of PEO polymer electrolyte with large electro-stable voltage ranges. Solution casting method has been used for the synthesis of polymer electrolyte. The essential physical characteristics of PEO in polymer matrices work as a polymer host in SPEs has been described in this review paper, along with several modifications to overcome these limitations. It has been seen that the addition of ionic liquid increases the all over conductivity of the solid polymer electrolyte in most cases also improves the electrical stability of the electrolyte. 相似文献
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Shubham Singh Negi Suneyana Rawat Pramod K. Singh Shri Prakash Pandey Tarun Yadav Monika Srivastava Ram Chandra Singh 《Macromolecular Symposia》2024,413(1):2300104
The potential applications of carbon black are expected to grow as science and technology improve offering up new possibilities for innovation throughout disciplines included in the field of energy storage. The present work shows the influence of carbon black to improve the ionic conductivity of the polymer electrolyte. The synthesis of polyethylene oxide: ammonium iodide based polymer electrolyte incorporated with carbon black varying from 0.01 to 0.06 wt% with respect to PEO: NH4I system by solution casting method. Different characterizations like polarized optical microscopy (POM), impedance spectroscopy, and ionic transference number (tion) are studied in detail. The maximum ionic conductivity is achieved at 0.05 wt% carbon black shows 1.20 × 10−5 S cm−1 at ambient temperature. In accordance with POM data, the amorphous region has increased whereas the crystalline region has shrunk which further indicated the increase in ionic conductivity . The value of (tion) is calculated to be 0.97 which shows the system is ionic in nature. PEO based polymer electrolyte doped carbon black can be used for the fabrication of energy storage devices. 相似文献
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研究了EtOH-H2O,n-PrOH-H2O,i-PrOH-H2O体系在CS膜和PEO/CS共混膜中的渗透蒸发性能。讨论了料液温度、料液浓度、共混膜组成对分离性能的影响,结果发现PEO的掺入能大大提高cs膜的渗透通量;而分离因子下降。同时从膜材料的聚集态结构出发对相关的渗透蒸发行为进行了讨论。对于PEO/CS共混膜,膜内自由体积的大小是影响分离性能的主要因素,小分子在膜中的渗透蒸发行为主要是由扩散过程控制的。本文还研究了PEO的掺入对壳聚塘膜强度的影响以及利用DSC谱研究PEO掺入后壳聚糖膜聚集态结构的变化。 相似文献
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本文采用广角 X射线衍射(WAXD)法,对以聚甲基丙烯酸甲酯(PMMA)为主链,以聚环氧乙烷(PEO)为支链的接枝共聚物(PMMA—PEO)及其导电金属盐络合物的结晶性能进行了研究,并讨论了结晶度和晶粒尺寸对导电络合物导电性能的影响。实验结果表明:1)PMMA-PEO接枝共聚物的结晶度随着PEO含量的增加而增加,随着金属盐浓度的增加而减小,且不同金属盐降低结晶度的大小顺序为LiClO_4>KSCN>FeCl_2;2) 支链PEO的晶粒尺寸受PEO含量的影响较小,但受金属的种类和浓度的影响很大;3)金属盐络合物的导电率受结晶度影响,不同金属盐形成的络合物的导电率大小顺序为PMM-PEO-KSCN>PMMA-PEO-LiClO_4>PMMA-PEO-FeCl_2。 相似文献
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深入研究了交替马来酸酐共聚物多缩乙二醇酯(CP350)两种锂盐络合物CP350/LiAsF_6和CP350/LiPF_6的离子传导性能,给出了与复阻抗谱相对应的等效电路.离子电导率随[Li]/[EO]的变化而出现一极大值,室温下,两体系电导率极大值分别为1.38×10(-4),8.32×10(-5)S/cm.电导率随温度升高而增加.导电行为呈非-Arrhenius特征.阴阳离子半径之和(r_c+r_a)愈大,离子电导率愈高. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(31):9200-9204
Ionic liquids (IL) hold a great potential as novel electrolytes for applications in electronic materials and energy technology. The functionality of ILs in these applications relies on their interface to semiconducting nanomaterials. Therefore, methods to control the chemistry and structure of this interface are the key to assemble new IL‐based electronic and electrochemical materials. Here, we present a new method to prepare a chemically well‐defined interface between an oxide and an IL film. An imidazolium‐based IL, which is carrying an ester group, is deposited onto cobalt oxide surface by evaporation. The IL binds covalently to the surface by thermally activated cleavage of the ester group and formation of a bridging carboxylate. The anchoring reaction shows high structure sensitivity, which implies that the IL film can be adhered selectively to specific oxide surfaces. 相似文献
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The acid-catalyzed reaction of dialdehyde starch with diethylene glycol and polyethylene oxide-400 under anhydrous conditions was studied as a new approach to the preparation of graft polymers of polyalkylene oxides on starch, the attachment of the side chains being through acetal linkages. The reaction was carried out in DMF in the presence of p-toluene sulfonic acid. It was found that increasing the reaction temperature, the diol concentration, or the reaction time led to an increase in the degree of grafting, as seen from the decrease in the dicarbonyl content of the products. Fusible graft polymers, soluble in water and in organic solvents, were obtained. 相似文献
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Complexes of 2, 6‐bis(hydroxymethyl)pyridine (dhmp) with different CuII salts [CuCl2·6H2O, Cu(ClO4)2·6H2O, Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O] are prepared ( 1 — 5 , respectively), studied by IR, and their crystal structures reported. Dependent on the anion kind, influences on the distortion of the co‐ordination polyhedron, the distribution of donor sites, the formation of a mono‐ or binuclear complex, and the resultant packing structure of the complex are observed, although in no case the counterions of the used CuII salts or water of hydration were found in the co‐ordination sphere. Crystal structures of 1 — 5 indicate hexaco‐ordination of the CuII ions with N2O4‐environment and show that 1 — 4 are mononuclear 2:1 (L:M) complexes, but 5 is a binuclear 4:2 complex. Crystallization of Cu(ClO4)2·6H2O with dhmp yielded two different complexes ( 2 / 3 ). In 3 , one of the dhmp components is mono‐deprotonated and acts as an anionic ligand. The same behavior is found in 5 . Whereas in the neutral ligand complexes 1 , 2 and 4 the basal planes are occupied by O donors, and N atoms are in the axial positions of the octahedrons, in 3 and 5 the bases are formed by two O and two N donor atoms, and O atoms are in the axes. Moreover, complex 3 shows the N atoms in trans position, but 5 in cis position. The packing of the cationic complex units is typical of strong and weak H bond interactions involving the counterions and hydroxylic or aromatic hydrogen atoms to yield complex network structures. 相似文献
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The crystal growth morphologies of manganese carbohydrazide perchlorate, iron carbohydrazide perchlorate, cobalt carbohydrazide perchlorate, nickel carbohydrazide perchlorate and cadmium carbohydrazide perchlorate were investigated by Bravais-Freidel-Donnay-Harker (BFDH) and growth morphology method. The results show that the crystal morphologies of them are close to oblong block shapes, and the growth on (101 )and (002) faces are the most important growth direction because of the minimum relative growth rates. According to the cleaved main growth faces, it can be inferred that crystal-control reagents with the active hydrogen atoms in the functional groups can effectively control the crystal morphology for them. In addition, the experimental morphologies of them were synthesized and observed by a coldfield-emission scanning electron microscope. It is concluded that AE model are nearer to experimental morphology, and more reliable to predict crystal morphologies for carbohydrazide perchlorates. 相似文献
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Bansal S Gaspari M Raj HG Kumar A Cuda G Verheij E Tyagi YK Ponnan P Rastogi RC Parmar VS 《Applied biochemistry and biotechnology》2008,144(1):37-45
Our earlier investigations identified acetoxy drug: protein transacetylase (TAase), a unique enzyme in the endoplasmic reticulum
(ER) catalyzing the transfer of acetyl groups from polyphenolic acetates (PA) to certain functional proteins. Recently we
have established the identity of TAase with ER protein calreticulin (CR) and subsequently transacetylase function of CR was
termed calreticulin transacetylase (CRTAase). CRTAase was purified and characterized from human placenta. CRTAase catalyzed
the acetylation of a receptor protein nNOS, by a model PA 7, 8-diacetoxy-4-methylcoumarin (DAMC), which was visually confirmed
by using antiacetyl lysine. The aim of this report was to provide tacit proof by providing mass spectrometry evidence for
CRTAase catalyzed acetylation of purified nNOS by DAMC. For this purpose, purified nNOS was incubated with DAMC and CRTAase,
the modified nNOS was analyzed by nanoscale LC-MS/MS, which recorded 11 distinct peptides with a significant score as acetylated
on lysine residues. The distribution was in order: lysines-24, -33, -38, -131, and -229 of the PDZ domain, Lys-245 of the
oxygenase domain, Lys-754 and -856 of FMN binding domain, Lys-989 of connecting domain and Lys-1300, -1321, and -1371 of the
NADPH-binding domain were acetylated. The results documented in this paper highlighted for the first time modification of
nNOS by way of acetylation. Our earlier work recorded the profound activation of platelet NADPH cytochrome P-450 reductase
and the acetylation of the reductase protein by DAMC, which also remarkably enhanced intracellular levels of nitric oxide.
The results reported here coupled with the aforementioned previous observations strongly implicate the possible role of the
acetylation of the reductase domain of nitric oxide synthase (NOS) in the NOS activation. In addition, the acetylation of
nNOS can be expected to potentiate the interaction with CR, eventually leading to the augmented catalytic activity of NOS
and expression of the related biological effects. 相似文献
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Electrochemiluminescence(ECL) is a powerful transduction technique used in biosensing and in vitro diagnosis, while the mechanism of ECL generation is complicated and affected by various factors. Herein the effect of ionic strength on ECL generation by the classical tris(2,2'-bipyridyl)ruthenium(II)[Ru(bpy)32+]/tri-n-propylamine(TPrA) system was investigated. It is clear that the ECL intensity decreases significantly with the increase of ionic strength, most likely arising from the reduced deprotonation rate of TPrA+·. We further combined microtube electrode(MTE) with ECL microscopy to unravel the evolution of ECL layer with the variation of ionic strength. At a low concentration of Ru(bpy)32+, the thickness of ECL layer(TEL) nearly kept unchanged with the ionic strength, indicating the surface-confined ECL generation is dominated by the oxidative-reduction route. While at a high concentration of Ru(bpy)32+, ECL generation is dominated by the catalytic route and TEL increases remarkably with the increase of ionic strength, because of the extended diffusion length of Ru(bpy)33+ at a reduced concentration of TPrA·. 相似文献
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Detection of Oxidative Damage of Synthetic Oligonucleotides Caused by Thallium(III) Complexes 下载免费PDF全文
Anna M. Nowicka Beata Krasnodebska‐Ostrega Beata Wrzosek Magdalena Jastrzebska Monika Sadowska Marcin Mackiewicz Zbigniew Stojek 《Electroanalysis》2014,26(2):340-350
Biologically important short sequences of DNA were treated with Tl(III) complexes. The chloride complex releases the Tl(III) cation and therefore oxidizes DNA components and at concentrations higher than 50 nM cuts the strands. The cuts are well seen in the EQCM plots. The change in the strand structure is well seen at CD and UV‐Vis spectra. The chelate complexes of Tl(III) do not damage the DNA strands. The SERS spectra were particularly useful in demonstration of the chemical changes and orientation vs. the surface changes of particular groups in the strands after interaction with TlCl4?. 相似文献