原位聚合法制备凝胶型离子液体／PMMA聚合物电解质

采用原位聚合法制备了含有N-甲基、丙基哌啶双三氟甲磺酰亚胺离子液体的凝胶型聚合物电解质．利用SEM和XPS测试了电解质膜与LiFePO4电极的界面状态,充放电循环后,在电解质膜与LiFePO4之间有一层薄膜,这层薄膜中含有N和S元素．结果表明,随着充放电的不断进行,凝胶型电解质中未聚合的甲基丙烯酸甲酯与电极表面的锂离子之间发生电子转移,形成SEI膜,至少要三个循环后才能形成稳定的SEI膜．随着SEI膜的增厚,放电容量增加,阻碍了电子转移,使系统更加的稳定．在不同倍率下测试了凝胶型离子液体／PMMA聚合物电解质电池性能,当充放电达到30个循环时,0．2、0．5和1C下电池比容量分别为132、128和120mAh／g．     

The curious case of 12-hydroxystearic acid — the Dr. Jekyll & Mr. Hyde of molecular gelators

A comprehensive review of the features driving self-assembly of 12-hydroxystearic acid (12-HSA), a low-molecular-weight gelator, and its applications in drug delivery and as other soft innovative materials are presented herein. 12-HSA is obtained via hydrogenation of ricinoleic acid naturally found in high concentrations in castor oil. The ability of 12-HSA to self-assemble is associated with the presence, position, and enantiomeric purity of the hydroxy group along the fatty acid chain. The polarity and position of the hydroxyl group facilitates more interaction possibilities leading to its exceptional self-assembly behavior giving rise to fibers, ribbons, and tubes in a variety of solvents. Upon self-assembly, 12-HSA undergoes crystallization resulting in the formation of high aspect ratio fibrillar structures due to noncovalent, intermolecular interactions forming self-spanning, three-dimensional networks (called self-assembled fibrillar networks) in both aqueous and organic solvents. Herein, emphasis is placed on emerging applications of 12-HSA supramolecular assemblies (i.e. responsive aqueous foams, gelled complex fluids, drug delivery systems, hydrogels, organogels, xerogels, and aerogel). The vast literature is compiled associated with 12-HSA self-assembly exploring supramolecular assemblies based on one ambidextrous gelator capable of assembling in aqueous and nonaqueous solvent.     

原位聚合法制备凝胶型离子液体/PMMA聚合物电解质

采用原位聚合法制备了含有N-甲基、丙基哌啶双三氟甲磺酰亚胺离子液体的凝胶型聚合物电解质．利用SEM和XPS测试了电解质膜与LiFePO₄电极的界面状态,充放电循环后,在电解质膜与LiFePO₄之间有一层薄膜,这层薄膜中含有N和S元素．结果表明,随着充放电的不断进行,凝胶型电解质中未聚合的甲基丙烯酸甲酯与电极表面的锂离子之间发生电子转移,形成SEI膜,至少要三个循环后才能形成稳定的SEI膜．随着SEI膜的增厚,放电容量增加,阻碍了电子转移,使系统更加的稳定．在不同     

On the behaviour of gelled fibre suspensions in steady shear

The shear rheological properties of suspensions of gelled agar fibres in a low viscosity Newtonian matrix fluid were investigated. Two classes of fibres, low aspect ratio fibres and high aspect ratio fibres with an aspect ratio of the order of 10 and 100 respectively were included in the investigations. For all fibre phase volumes investigated, from as low as 0.01 upwards, the flow curves are characterised by an apparent yield stress followed by shear-thinning which was independent of the fibre aspect ratio. Based on our analysis of the flow curves, we conclude that the high aspect ratio fibres behave like flexible threads in contrast to the low aspect ratio fibres whose high shear relative viscosity is successfully described by a relation for long rigid rods. These findings are supported by flow visualisation using an optical shearing stage coupled to a light microscope.