聚合物固体电解质中的离子状态与导电机理的研究

制备得到了一种新颖的聚氨酯和丙烯酸酯复合梳形交联聚合物 (Combcross linkedpolymer) ,并以此聚合物为基体加入不同含量的高氯酸锂盐制得一系列聚合物固体电解质 ,其室温电导率可以达到 3 4× 10 - 5S·cm- 1 .通过Raman、DSC、SEM及电性能等研究了电解质中的盐浓度与离子存在状态及离子电导率之间的关系 .结果显示随着盐浓度的增加 ,聚合物固体电解质中离子对的比例和电导率都迅速增加 ,说明离子对 (由多个醚氧原子、阴离子和阳离子组成 )对体系导电起着积极的作用 .     

聚氨酯/石墨烯纳米复合物的原位制备及温度-电阻行为

采用原位聚合法,利用蓖麻油基聚氨酯预聚体与还原石墨烯残留羟基或羧基反应,制得聚氨酯/石墨烯纳米复合物,并利用红外光谱和拉曼光谱对其分子结构进行了表征.此外,分别采用热重分析仪、X-射线衍射、扫描电子显微镜、ZC36型高阻计等表征手段对其热稳定性、形态结构以及电阻率-温度行为进行了分析.结果显示,石墨烯添加致使复合物的交联网络增加和物理交联增强.因而,聚氨酯/石墨烯复合物的室温电阻率有所升高和电阻率-温度行为增强.尤其是,当掺杂3%石墨烯时,聚氨酯复合物的正电阻率温度效应(PTC效应)提高近3个数量级.因此,聚氨酯基复合物应该是一种具有潜在应用价值的低掺杂PTC纳米复合物材料.     

硬段含量对聚氨酯弹性体的吸水动力学及力学性能的影响

合成了硬段含量分别为30 wt%、37 wt%和45 wt%的聚醚型聚氨酯弹性体(PTMG-PU).研究了硬段含量、水浸温度和试样厚度对PTMG-PU吸水动力学的影响.研究结果表明：PTMG-PU在25℃～60℃之间的吸水动力学过程可以用Fick模型进行拟合；扩散系数和平衡吸水率随着硬段含量的增加均呈逐渐降低的趋势，水分子扩散活化能和指前因子均随着硬段含量的增加而增加，说明硬段含量越高，水分子需要克服的传输能垒越高.进一步，吸水导致聚氨酯弹性体的拉伸断裂强度、100%定伸强度和拉伸模量等力学性能出现明显的下降，这不仅是由于水分子与聚氨酯弹性体的软段相发生了增塑作用，而且水分子也与部分硬段相微区发生了作用，导致部分硬段相微区瓦解.     

Chiralcel OD-RH手性柱拆分卡维地洛对映体

采用Ch iralcelOD-RH(纤维素3,5-二甲基苯基氨基甲酸酯)手性固定相高效液相色谱法研究了乙腈-高氯酸钠缓冲盐体系对卡维地洛的手性拆分情况,讨论了流动相的各个因素(有机相的种类和比例、缓冲盐浓度、酸度等)对手性拆分的影响。在乙腈-高氯酸钠缓冲盐(pH 5.5,50 mmol/L)的体积比为35∶65的色谱条件下,卡维地洛对映体获得了基线分离。     

聚丁二酸丁二酯与高氯酸锂络合物的结构与离子导电性

本文从丁二酸二甲酯和丁二醇合成了聚丁二酸丁二酯,并以高氯酸锂为掺杂剂制备了固体电解质。FT-IR、NMR、XPS测试发现酯基上的氧原子参与络合。WAXD、DSC等测试分析结果表明:络合物和聚酯的晶体相同;LiClO_4主要溶解在无定形区;盐的溶解降低聚酯的熔点、结晶度和结晶速度,而提高玻璃化温度;在低盐浓度区络合物熔点与盐浓度关系符合Flory-Huggins理论。络合物的电导率随盐浓度变化出现极大值,在低盐浓度区电导率与浓度的对数成线性关系。电解质的导电行为不能简单地为Arrhenius和WLF方程所解释。从扩散角度推导了导电方程,并描述了离子导电过程。     

一种梳状高分子固体电解质的分子运动和离子导电性

用交流复阻抗谱和动态粘弹谱等对交替马来酸酐共聚物多缩乙二醇酯衍生物及其ＬｉＣｌＯ４盐复合物进行了研究．结果表明，在Ｌｉ／ＥＯ＝０．０７—０．０４２范围内，从１７３Ｋ到３７３Ｋ，本聚合物一高氯酸锂复合体系的动态粘弹谱存在着两个明显的转变，其中β转变归属于ＰＥＯ的侧链玻璃化转变，转变温度随ＬｉＣｌＯ４盐浓度的增加而增加。α转变归属于主链玻璃化转变，在Ｌｉ／ＥＯ＝０．０２８时有极大值。盐浓度与电导率的关系与通常不一样，在所研究盐浓度范围内观察到两个峰，其一在Ｌｉ／ＥＯ＜０．０１４，另一峰在Ｌｉ／ＥＯ＝０．０２８．电导率与温度的依赖关系不符合Ａｒｒｈｅｎｉｕｓ行为；以ｌｇσ对１／Ｔ－Ｔ０作图，用侧链玻璃化转变温度Ｔβ作Ｔ０时，呈典型的ＶＴＦ行为。该体系室温电导率最高可达６×１０－６ｓ／ｃｍ．     

具有明确硬段结构的水性聚氨酯脲的研究

通过逐步反应由4,4′-二苯基甲烷二异氰酸酯、2,2-二羟甲基丙酸和1,4-丁二醇,合成了结构明确的硬段模型化合物.通过13C NMR对其序列结构进行了表征,并通过FTIR、DSC和WAXD对其形态结构进行了研究.进一步制备了具有这类规整结构硬段的水性聚氨酯脲,初步考察了水分散液及其成膜后的性能.实验结果表明,这类聚氨酯脲水分散液的粒径小于110nm,在室温下贮存期大于一年,成膜后具有优异的耐水性能以及表面疏水性能.     

水性聚氨酯硬段含量对其氢键相互作用及性能的影响

异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸(DMPA)作为硬段,合成了水性聚氨酯。 研究了硬段含量（质量分数）对乳液稳定性、膜耐热和力学性能等的影响。 当硬段质量分数低于26%时,乳液贮存稳定性较差。 随着硬段含量增加,聚氨酯膜拉伸强度迅速增加,断裂伸长率略有降低;红外光谱显示,自由的N-H伸缩振动峰强度减弱,氢键化N-H的振动峰强度增加;同时C=O伸缩振动峰整体向低波数方向移动,C=O伸缩振动峰峰形有明显的变化;DSC测试在50～125 ℃出现明显的氢键解离现象,吸热峰增强,证实了氢键作用力随着硬段含量的增加逐渐增强。 TG测试表明,水性聚氨酯硬段和软段分步解离,随着硬段含量的增加,硬段分解温度降低,水性聚氨酯耐热性能下降。     

主链含酰亚胺环和炔基的聚酰亚胺型聚氨酯弹性体的合成及阻燃性能简

以均苯四甲酸酐、D,L-苯丙氨酸和1,4-丁炔二醇为原料合成了一种含有酰亚胺环和炔基的二醇,并以其为扩链剂,采用预聚体法,与4,4-二苯基甲烷二异氰酸酯(MDI)和聚四氢呋喃醚二醇(PTMG)反应,合成了不同硬段含量的主链含有酰亚胺环和炔基的热塑性聚酰亚胺型聚氨酯弹性体. 用红外光谱(FTIR)、电子拉力机、热失重分析(TG)、广角X射线衍射(XRD)、UL-94垂直燃烧和极限氧指数对聚酰亚胺型聚氨酯弹性体进行了表征. 结果表明,这种聚氨酯呈现出无定形结构;其拉伸强度随着硬段含量的增加而增大;与传统的热塑性聚氨酯相比,酰亚胺环和炔基改性的聚酰亚胺型聚氨酯弹性体的热分解过程非常缓慢,呈现出较好的热稳定性;不同硬段含量的聚酰亚胺型聚氨酯弹性体的UL-94垂直燃烧均达到V-2级别;其极限氧指数随着硬段含量的增加而增大.     

交联密度对脂肪族聚氨酯弹性体结构与性能的影响

采用异佛尔酮二异氰酸酯(IPDI)与聚醚二元醇、三羟甲基丙烷(TMP)和1,4-丁二醇反应制备了具有不同交联密度的脂肪族聚氨酯弹性体.研究结果表明,当聚氨酯弹性体的硬段含量为40 wt%时,随着TMP含量的增加,聚氨酯弹性体的交联密度线性增加.随着聚氨酯弹性体交联密度的提高,聚氨酯中硬段相的玻璃化转变温度由32℃降为2...     

超支化聚氨酯固体电解质导电性能的光谱学研究

用超支化聚氨酯 +线性聚氨酯作为基体 ,LiClO4作为离子源制得聚合物固体电解质 .用Raman光谱 ,FTIR光谱等光谱学方法研究了聚合物电解质中盐离子和聚合物基团之间的相互作用 .研究表明超支化聚氨酯对盐有较好的溶解作用 .研究还表明超支化聚氨酯加入有利于提高体系的电导率     

A novel ionic‐conduction mechanism based on polyurethane electrolyte

A series of poly(ethylene glycol)–polyurethane (PEG–PU)/sodium perchlorate (NaClO₄) solid electrolytes were prepared, and their properties were characterized with Fourier transform infrared spectroscopy, differential scanning calorimetry, complex impedance analysis, and atomic force microscopy. Results showed that the oxygen atoms of carbonyl and ether oxygen groups had different activities on cations. Both carbonyl and ether oxygen groups participated in the ionic‐transport process in PU‐based electrolytes. There existed a coordination competition between sodium cations and different oxygen atoms in soft and hard segments of PU. For the PEG–PU/NaClO₄ system investigated, amorphous regions and interfacial regions between the amorphous and microcrystalline phases were responsible for ionic conduction. A new ionic‐transport mechanism, based on the existence of conduction pathways not only in amorphous regions but also in interfacial regions of microphase‐separated PU‐based electrolytes, is sketched. Moreover, at a particular concentration of doped salt (EO/NaClO₄ 12), the PEG–PU/NaClO₄ complex revealed a phase‐transition point in the morphology and exhibited minimum apparent activation energy and maximum ionic conductivity. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1246–1254, 2001     

Cationic and anionic environments in LiTFSI-doped di-ureasils with application in solid-state electrochromic devices

Fourier Transform mid-infrared and Raman spectroscopies were used to investigate the cation/polymer, cation/urea bridge, cation/anion and hydrogen bonding interactions in poly(oxyethylene) (POE)/siloxane di-ureasil networks prepared by the sol–gel route and doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Materials with compositions 200 ?n ? 5 (where n expresses the molar ratio OCH₂CH₂/Li⁺) were studied. The Li⁺ ions coordinate to the urea carbonyl oxygen atoms over the whole range of salt concentration considered. Bonding to the ether oxygen atoms of the POE chains occurs at n ? 40, although a significant fraction of the POE chains remain non-coordinated. In these high salt content samples, the cations interact with the anions forming contact ion pairs. “Free” ions are probably the main charge carriers at the room temperature conductivity maximum of these ormolytes.     

Synthesis and Crystal Structure of Complex of Sodium Perrhenate with Tetraethyl p-tert-Butylcalix[4]arene Tetraacetate

Recently,theconformationofthecalixarenehasbeenshowntobeimportantincontrollingtheseIectivityofthereceptor.Forexample,sodiumioncouldbeboundverystronglybyesterderivativesofcalix[4]areneintheconeconformationl.Wehavefoundthatinthepresenceofcertainamountofsodiumion,microamountofReO4-canbequantitativelyextractedintol,2-dichloroethanebytheligandtetraethylp-tert-butylcalix[4]arenetetraacetate(L).ItshowsthatthepresenceofNa inaqueoussolutioncanpromotetheformationofhydrophobiccomplex[NaL] .ReO'-whichc…     

Study of microstructural characterization and ionic conductivity of a chemical-covalent polyether-siloxane hybrid doped with LiClO4

The chemical-covalent polyether-siloxane hybrids (EDS) doped with various amounts of LiClO4 salt were characterized by FT-IR, DSC, TGA, and solid-state NMR spectra as well as impedance measurements. These observations indicate that different types of complexes by the interactions of Li+ and ClO4- ions are formed within the hybrid host, and the formation of transient cross-links between Li+ ions and ether oxygens results in the increase in T(g) of polyether segments and the decrease in thermal stability of hybrid electrolyte. Initially a cation complexation dominated by the oxirane-cleaved cross-link site and PEO block is present, and after the salt-doped level of O/Li+ = 20, the complexation through the PPO block becomes more prominent. Moreover, a significant degree of ionic association is examined in the polymer-salt complexes at higher salt uptakes. A VTF-like temperature dependence of ionic conductivity is observed in all of the investigated salt concentrations, implying that the diffusion of charge carrier is assisted by the segmental motions of the polymer chains. The behavior of ion transport in these hybrid electrolytes is further correlated with the interactions between ions and polymer host.     

Quaternary ammonium room-temperature ionic liquid including an oxygen atom in side chain/lithium salt binary electrolytes: ionic conductivity and 1H, 7Li, and 19F NMR studies on diffusion coefficients and local motions

A room-temperature ionic liquid (RTIL) of a quaternary ammonium cation having an ether chain, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)amide (DEME-TFSA), is a candidate for use as an electrolyte of lithium secondary batteries. In this study, the electrochemical ionic conductivity, sigma, of the neat DEME-TFSA and DEME-TFSA-Li doped with five different concentrations of lithium salt (LiTFSA) was measured and correlated with NMR measurements of the diffusion coefficients D and the spin-lattice relaxation times T1 of the individual components DEME (1H), TFSA (19F), and lithium ion (7Li). The ion conduction of charged ions can be activated with less thermal energy than ion diffusion which contains a contribution from paired ions in DEME-TFSA. In the doped DEME-TFSA-Li samples, the sigma and D values decreased with increasing salt concentration, and within the same sample generally DLi相似文献   

无定形梳状高分子固体电解质的二重玻璃化转变及典型VTF特征

研究了交替马来酸酐共聚物多缩乙二醇酯(CP350)-LiNO₃络合物的热行为及离子导电性。实验表明:CP350/LiNO₃络合物在所研究的[Li]/[EO]配比范围呈均相无定形并具有二重玻璃化转变。2个玻璃化转变温度均随盐含量的增加而上升。离子电导率随盐浓度的变化出现1个极大值,室温电导率最大可达3.72×10^-5S/cm.导电行为呈典型VTF特征。     

Supramolecular polymer/metal salt complexes containing quadruple hydrogen bonding units

A supramolecular material containing quadruple hydrogen bonding sites was prepared by reacting the amines of methyl isocytosine and the epoxy groups of poly (ethylene glycol diglycidyl ether). This supramolecular polymer was complexed with metal salt, that is potassium iodide, to produce polymer electrolytes, and their physical properties, specific interactions, and conductivity behavior were investigated. The ionic conductivity of polymer electrolytes continuously increased with increasing salt concentration up to 0.4 of salt weight fraction, presenting usually high solubility limit of salt in the supramolecular polymer. Wide angle X‐ray scattering data also presented that the metal salt was completely dissolved in the supramolecular polymer up to 0.4 of salt weight fraction. Upon the introduction of metal salt, the mechanical properties of the supramolecular polymer were significantly enhanced by around 10 times and the glass transition temperature of the polymer increased by about 50 °C, as revealed by complex melt viscosities and differential scanning calorimetry. These unusual behaviors of salt solubility and mechanical properties for supramolecular polymer/metal salt complexes were attributed to the strong, additional metal ion coordination to hydrogen bonding sites as well as ether oxygens of polymer matrix, as supported by FTIR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3181–3188, 2007     

A new hetero-bimetallic coordination polymer, cesium, and sodium complex of styphnate trihydrate [CsNa(TNR)(H2O)3] n

A new hetero-bimetallic coordination polymer, cesium, and sodium complex of styphnate trihydrate [CsNa(TNR)(H₂O)₃] _n (TNR: 2,4,6-trinitroresorcinol dianion, the dianion of styphnic acid) was synthesized. The title complex was characterized by X-ray single crystal diffraction, element analysis, FT-IR, DSC, TG-DTG studies. In the title polymer molecule, the cesium cation is coordinated by 13 oxygen atoms: three originated from the water molecule and the others are from the nitro group and the phenolic hydroxyl group of TNR; the sodium cation is surrounded by six oxygen atoms from water molecules and TNR forming a distorted octahedron. The coordination polymer crystal was formed by the bridging ligands of water molecules and TNR connected with different cesium and sodium cations.     

Hyperbranched polymers with thermoresponsive property highly sensitive to ions

The salt effects on the water solubility of thermoresponsive hyperbranched polyethylenimine and polyamidoamine possessing large amounts of isobutyramide terminal groups (HPEI-IBAm and HPAMAM-IBAm) were studied systematically. Eight anions with sodium as the counterion and ten cations with chloride as the counterion were used to measure the anion and cation effects on the cloud point temperature (T(cp)) of these dendritic polymers in water. It was found that the T(cp) of these dendritic polymers was much more sensitive to the addition of salts than that of the traditional thermoresponsive linear polymers. At low anion concentration, the electrostatic interaction between anions and the positively charged groups of these polymers was dominant, resulting in the unusual anion effect on the T(cp) of these polymers in water, including (1) T(cp) of these dendritic polymers decreasing nonlinearly with the increase of kosmotropic anion concentration; (2) the chaotropic anions showing abnormal salting-out property at low salt concentration and the stronger chaotropes having much pronounced salting-out ability; (3) anti-Hofmeister ordering at low salt concentration. At moderate to high salt concentration, the specific ranking of these anions in reducing the T(cp) of HPEI-IBAm and HPAMAM-IBAm polymers was PO(4)(3-) > CO(3)(2-) > SO(4)(2-) > S(2)O(3)(2-) > F(-) > Cl(-) > Br(-) > I(-), in accordance with the well-known Hofmeister series. At moderate to high salt concentration, the specific ranking order of inorganic cations in reducing the T(cp) of HPEI-IBAm polymer was Sr(2+) ≈ Ba(2+) > Na(+) ≈ K(+) ≈ Rb(+) > Cs(+) > NH(4)(+) ≈ Ca(2+) > Li(+) ≈ Mg(2+). This sequence was only partially similar to the typical Hofmeister cation series, whereas at low salt concentration the cation effect on T(cp) of the dendritic polymer was insignificant and no obvious specific ranking order could be found.