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。     

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…

研究了交替马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。     

混合离子液体对聚甲基丙烯酸甲酯分子链缠结及松弛行为的影响

首先通过两步法合成了具有双咪唑环阳离子结构的离子液体(DIL),并将其与单咪唑环离子液体(MIL)进行混合以调控黏度变化,混合离子液体(ILs)的黏度符合对数混合规则且随温度变化呈现Arrhenius型流体行为.进一步通过动态流变、示差扫描量热(DSC)、电化学测试等方法研究了混合离子液体中DIL比例对聚甲基丙烯酸甲酯(PMMA)链缠结和松弛行为的影响,并讨论了PMMA/ILs体系热稳定性、玻璃化转变及离子电导率等的变化.结果表明,DIL独特的双咪唑环结构可与PMMA分子形成更多相互作用位点,从而导致凝聚缠结的形成,很大程度上限制了PMMA分子链的运动和松弛.随DIL含量增加,PMMA/ILs体系的松弛时间、热分解温度、玻璃化转变温度等参数均呈增大趋势,但其离子电导率有所损失,这与DIL较大的分子尺寸和运动能力有关.     

增塑剂对PVA碱性聚合物电解质电化学性能的影响

通过溶解―铸膜法制备聚乙烯醇(PVA)-KOH-H2O碱性聚合物电解质膜。向聚合物中添加增塑剂丙三醇(GROL)和碳酸丙烯酯(PC)来提高离子电导率。X射线晶体衍射分析(XRD)结果表明,添加增塑剂未改变聚合物的物相结构,薄膜仍主要为不定形态。差示扫描热分析(DSC)结果显示,添加增塑剂后聚合物电解质膜的玻璃化转变温度降低,促进了电解质膜向不定形态转变。电解质膜室温离子电导率随增塑剂添加而增大,增塑剂超过一定量后离子电导率开始下降。PC对提高离子电导率的作用优于GROL。循环伏安测试结果显示,电解质膜的电化学稳定性窗口随增塑剂的添加而有所变窄,但仍显示了较好的电化学稳定性。     

非水溶剂中稀土离子和穴醚（2.2）配合物的电导研究

用电导法研究了２５℃时，硝酸稀土和穴醚在不同溶剂中的配位行为。计算了１：１配合物的稳定常数及摩尔电导率，在非水溶剂（ＣＨ３）２ＣＯ．ＣＨ３ＣＮ．ＣＨ３ＯＨ和ＤＭＦ中，由于配位过程中伴随着Ｌｎ离子的溶剂化作用，稀土和穴醚配合的稳定常数随Ｌｎ原子序数的增加而变化不大。     

三价镧系元素离子Nd~(3 )、Gd~(3 )和Tm~(3 )与肾上腺素的配合物研究

本文采pH电位滴定法和电子光谱法进行了肾上腺素与f区元素[Nd~(3 )、Gd~(3 )和Tm~(3 )]溶液的反应机理、配合物组成、配位原子位置、配位键性质和配合物稳定性等方面的研究。肾上腺素对Nd~(3 )和Tm~(3 )的f-f电子跃迁产生了微扰作用,致使其配合物的吸收谱线红移。在350～650nm区间内,三种f区离子形成的配合物的吸收光谱随pH值的提高而发生紫移现象。     

苯酰化聚苯醚/聚苯乙烯共混物相容性研究

采用DSC方法研究了聚苯乙烯(PS)和苯甲酰化聚苯醚(APPO)共混体系的相容性.相容共混体系Gordon-Taylor方程K参数随苯甲酰化程度(取代度)增加而变小,其玻璃化转变区随取代度增加而变宽,取代度大于76mol％时,共混物呈现双玻璃化转变.APPO/PS共混体系热诱导相图同时存在LCST和UCST现象,且相行为是可逆的.     

原位聚合制备的离子液体/聚合物电解质的研究

采用原位聚合制备出新型的BMIPF6/PMMA聚合物电解质透明弹性膜. 研究结果表明, BMIPF6/PMMA聚合物电解质体系在305 ℃时仍具有较好的热稳定性, 其安全性能优于含有机溶剂的传统非水电解质体系. 随着离子液体含量的增加, 其玻璃化转变温度逐渐减小, 离子电导率升高; 且离子电导率与温度的关系服从VTF方程. 其中, 当BMIPF6的质量分数为50%时, 该聚合物电解质的室温离子电导率高达0.15 mS/cm.     

苯酰化聚苯醚—聚苯乙烯共混物相容性研究

采用DSC方法研究了聚苯乙烯和苯甲酰化聚苯醚共混体系的相容性。相容共混体系Gordon-TayIov方程K参数随苯甲酰化程度(取代度)增加而变小,其玻璃化转变区随取代度增加而变宽,取代度大于76mol％时,共混物呈现双玻璃化转变。A~(49)ppo/pS_(19)共混体系热诱导相图同时存在高和低临界共溶温度,且此相行为是可逆的。     

苯酰化聚苯醚/聚苯乙烯共混物相容性研究

 采用DSC方法研究了聚苯乙烯(PS)和苯甲酰化聚苯醚(APPO)共混体系的相容性.相容共混体系Gordon-Taylor方程K参数随苯甲酰化程度(取代度)增加而变小,其玻璃化转变区随取代度增加而变宽,取代度大于76mol％时,共混物呈现双玻璃化转变.APPO/PS共混体系热诱导相图同时存在LCST和UCST现象,且相行为是可逆的.     

CPI induction of liquid crystal behaviour in triphenylenes with a mixture of hydrophobic and hydrophilic side chains

2,3,6,7,10,11-Hexasubstituted triphenylenes have been synthesized that contain a mixture of hydrophobic (C₆H₁₃O) and hydrophilic (CH₃OCH₂CH₂OCH₂CH₂O) side chains. At one extreme HAT6 (1a) (six hydrophobic chains) shows thermotropic behaviour and at the other TP6EO2M (1e) (six hydrophilic chains) shows lyotropic behaviour. Of the triphenylenes with a mixture of hydrophobic and hydrophilic side chains, only the triphenylene with one hydrophilic side chain and five hydrophobic side chains (1b) gives a thermotropic columnar phase. None of the others show liquid crystal behaviour. However, all of these triphenylenes form binary 1:1 compounds when mixed with PDQ9 (2a) and with PTP9 (2b). These CPI (complimentary polytopic interaction) stabilized compounds give thermotropic hexagonal columnar phases over wide temperature ranges.     

The development of polar discotic metallomesogens Vanadyl 1,3-diketonate complexes

The dependence of mesomorphism of 1,3-diketonate vanadium-oxo (vanadyl) complexes on the number of side chains was investigated. These complexes have a large dipole normal to the disc plane and are under investigation in an effort to generate discotic phases with polar order. Relatively complex phase behaviour is observed when the vanadyl 1,3-diketonate complexes are appended with four phenyl groups with two octyloxy or decyloxy side chains each for a total of eight side chains. These complexities are most likely related to the order/disorder associated with the polar vanadyl group. Vanadyl 1,3-diketonate complexes with four side chains were prepared by replacement of two of the phenyl groups with methyl or trifluoromethyl groups, and these complexes displayed only crystal phases. Complexes with two trialkyloxy phenyls and two dialkyloxy phenyls were synthesized and found to display a very stable D_hd phase. The presence of additional alkyloxy groups was found also to promote a linear chain structure, (i.e. --V=O--V=O--), in the crystal phase.     

Synthesis and mesomorphic structures of comb liquid-crystalline polymers with lipopeptidic side chains

Lipopeptidic macromonomers were synthesized from bi-functional lipids by two methods and transformed into comb copolymers with lipopeptidic side chains by radical polymerization of their acrylate, methacrylate, acrylamide or methacrylamide terminal group. X-ray diffraction and differential scanning calorimetry studies showed that comb copolymers exhibit both a thermotropic and a lyotropic behaviour and present smectic and nematic mesophases. The influence of the solvent concentration, the degree of polymerization of the peptidic chains and the nature of the main chains on the structural parameters of the smectic mesophases were established in the case of copolymers with liposarcosine side chains.     

Dynamic Properties of Polyampholyte Hydrogel Elucidated by Proton NMR Spin-spin Relaxation Time

1H spin-spin relaxation time（T2） measurement of polyampholyte hydrogel poly（methylacrylic acidacryloyloxyethyl trimethylammonium chloride）[P（MA-DAC）] in different pH, ionic strength and temperature was carried out to reveal the molecular mobility. Spontaneous volume transition of the polyampholyte hydrogel was also investigated by spin-spin relaxation time measurement. Meanwhile T2 and the proton component fraction were acquired to study the swelling behaviour of the hydrogel. Moreover the changes of T2 characterized the molecular mo- bility of polyampholyte hydrogel in various swelling states. And the results suggest that the mobility of the main chains and a few free side chains（the long T2） of P（MA-DAC） was dominated by the mesh size in the hydrogel net- work, depending on the swelling ratio（Q） and the mobility of the side chains（the short T2） was influenced by electrostatic interaction between different charges in polymer side chains. Finally the T2 measurements of P（MA-DAC） hydrogel in the spontaneous swelling-deswelling process demonstrated the electrostatic interaction of the charged side chains caused deswelling behavior. At the same time, the mobility state transition temperature of the charged side chains was also studied by the lH spin-spin relaxation time measurements, and the transition activation energy of the side chains is 2.72 kJ.     

The development of polar discotic metallomesogens Vanadyl 1,3-diketonate complexes

Abstract

The dependence of mesomorphism of 1,3-diketonate vanadium-oxo (vanadyl) complexes on the number of side chains was investigated. These complexes have a large dipole normal to the disc plane and are under investigation in an effort to generate discotic phases with polar order. Relatively complex phase behaviour is observed when the vanadyl 1,3-diketonate complexes are appended with four phenyl groups with two octyloxy or decyloxy side chains each for a total of eight side chains. These complexities are most likely related to the order/disorder associated with the polar vanadyl group. Vanadyl 1,3-diketonate complexes with four side chains were prepared by replacement of two of the phenyl groups with methyl or trifluoromethyl groups, and these complexes displayed only crystal phases. Complexes with two trialkyloxy phenyls and two dialkyloxy phenyls were synthesized and found to display a very stable D_hd phase. The presence of additional alkyloxy groups was found also to promote a linear chain structure, (i.e. ??V?O??V?O??), in the crystal phase.     

Aggregation behaviour of peptide-polymer conjugates containing linear peptide backbones and multiple polymer side chains prepared by nitroxide-mediated radical polymerization

A series of peptides with an alternating sequence of alkoxyamine conjugated lysine and glycine residues were synthesized by classical solution phase peptide coupling. The resulting peptides containing up to eight alkoxyamine moieties were used as initiators in nitroxide-mediated polymerization (NMP) to obtain peptide-polymer conjugates with well defined linear peptide backbones and a defined number of polymeric side chains. Polymerization of styrene and N-isopropylacrylamide (NIPAM) occurred in a highly controlled fashion. Molecular weight and polydispersity index (PDI) were determined by gel permeation chromatography (GPC). Aggregation behaviour of these hybrid materials was investigated by dynamic light scattering (DLS) and atomic force microscopy (AFM). Depending on composition, number and length of the polymer side chains, the conjugates aggregate to different topologies. Whereas peptide-polystyrene conjugates may aggregate to so called honeycomb structures, peptide-poly-N-isopropylacrylamide conjugates show differentiated aggregation behaviour.     

The Effect of the Side Chain on Gelation Properties of Bile Acid Alkyl Amides

Six bile acid alkyl amide derivatives were studied with respect to their gelation properties. The derivatives were composed of three different bile acids with hexyl or cyclohexyl side chains. The gelation behaviour of all six compounds were studied for 36 solvents with varying polarities. Gelation was observed mainly in aromatic solvents, which is characteristic for bile-acid-based low molecular weight gelators. Out of 108 bile acid-solvent combinations, a total of 44 gel systems were formed, 28 of which from lithocholic acid derivatives, only two from deoxycholic acid derivatives, and 14 from cholic acid derivatives. The majority of the gel systems were formed from bile acids with hexyl side chains, contrary to the cyclohexyl group, which seems to be a poor gelation moiety. These results indicate that the spatial demand of the side chain is the key feature for the gelation properties of the bile acid amides.     

Ionic hexagonal columnar metallomesogens derived from tetrabenzo[b,f,j,n] [1,5,9,13]tetraazacyclohexadecine

A series of transition metal (Ni, Cu, Pd) complexes derived from macrocyclic tetrabenzo[b,f,j,n] [1,5,9,13]tetraazacyclohexadecine (TAAB) was synthesized and their mesomorphic properties studied by differential scanning calorimetry, polarized optical microscopy and X-ray powder diffraction (XRD). These compounds have eight alkoxy side chains attached around the central molecular core and form disc-like molecules. All the derivatives exhibited columnar mesophases over a wide range of temperature. The mesomorphic behaviour was found to be dependent on the incorporated metal and the carbon length of the alkoxy side chains. The clearing temperatures decreased in the order M = Ni > Pd > Cu; this decrease was probably due to the size of the metal ions. Some derivatives with shorter side chains (n = 10, 12) were room temperature liquid crystals. All compounds were found to exhibit hexagonal columnar (Col_h) phases which were confirmed by powder XRD.     

4‐Aryl‐3,5‐bis(arylethynyl)aryl‐4H‐1,2,4‐triazoles: Multitasking Skeleton as a Self‐Assembling Unit

The synthesis of a series of 4‐aryl‐3,5‐bis(arylethynyl)aryl‐4H‐1,2,4‐triazoles derivatives is reported and the influence exerted by peripheral substitution on the morphology of the aggregates generated from these 1,2,4‐triazoles is investigated by SEM imaging. The presence of paraffinic side chains results in long fibrillar supramolecular structures, but unsubstituted triazoles self‐assemble into thinner ribbons and needle‐like aggregates. The crystals obtained from methoxy‐substituted triazoles have been utilised to elaborate a model that helps to justify aggregation of the investigated 1,2,4‐triazoles, in which the operation of arrays of C?H???π non‐covalent interactions plays a significant role. The results presented herein demonstrate the ability of simple molecules to behave as multitasking scaffolds with different properties, depending on peripheral substitution. Thus, although 1,2,4‐triazoles without long paraffinic side chains exhibit optical waveguiding behaviour, triazoles endowed with peripheral paraffinic side chains exhibit hexagonal columnar mesomorphism.     

Mesomorphic properties of monocyclic troponoids with a semi-fluorinated side group

Eight types of monocyclic troponoids with alkoxy, acyloxy, and semi-fluorinated side chains were synthesized to investigate their thermal behaviour. They showed smectic A phases. The troponoids with a fluorinated side chain had higher transition temperatures than the corresponding non-fluorinated compounds.