Ion shielding functional separator using halloysite containing a negative functional moiety for stability improvement of Li–S batteries

Lithium–sulfur batteries are one of the attractive next-generation energy storage systems owing to theienvironmental friendliness,low cost,and high specific energy densities.However,the low electrical conductivity of sulfur,shuttling of soluble intermediate polysulfides between electrodes,and low capacitretention have hampered their commercial use.To address these issues,we use a halloysitemodulated(H-M)separator in a lithium–sulfur battery to mitigate the shuttling problem.The H-M separator acts as a mutual Coulombic repulsion in lithium-sulfur batteries,thereby selectively permitting Lions and efficiently suppressing the transfer of undesired lithium polysulfides to the Li anode sideMoreover,the use of halloysite switches the surface of the separator from hydrophobic to hydrophilicconsequently improving the electrolyte wettability and adhesion between the separator and cathodeWhen sulfur-multi-walled carbon nanotube(S-MWCNT)composites are used as cathode active materialsa lithium–sulfur battery with an H-M separator exhibits first discharge and charge capacities of 1587 an1527 m Ah g-1,respectively.Moreover,there is a consistent capacity retention up to 100 cyclesAccordingly,our approach demonstrates an economical and easily accessible strategy for commercialization of lithium–sulfur batteries.

SYNTHESIS OF FUNCTIONALIZED CALIX[4]ARENE BEARING [M]DAZOLE MOIETY TO SERVE AS CATALYTIC FUNCTION

Synthesis of catix[4]arene with one imidazolyl group on the upper rim is presented.

Synthesis and Properties of High Performance Functional Polyimides Containing Rigid Nonplanar Conjugated Fluorene Moieties

A diamine(WuFDA) containing vertical rigid non-planar conjugated fluorene moiety and low polarizability group(C―F)was designed and synthesized through three steps of reactions(halogenated reaction, Suzuki coupling reaction, and reduction reaction).Four kinds of high performance functional polyimides(WuFPI-6 F, WuFPI-BP, WuFPI-BT, and WuFPI-PM) were thus prepared by the condensation polymerization of WuFDA with four commercial dianhydride 6 FDA, BPDA, BTDA, and PMDA, respectively. The polyimides exhibited low dielectric constant, excellent thermal stability, outstanding solubility, good film-forming property, and mechanical properties. The dielectric constants of the polyimides were in the range of 2.28-2.88(f = 10~4 Hz). The 5% weight-loss temperatures(Td 5%)in nitrogen were in the range of 555-584 °C, and the glass transition temperatures(T_g) were in the range of 408-448 °C. The weight loss of WuFPI-BP maintaining at 450 and 500 °C for half an hour was only 0.33% and 1.26%, respectively. All the WuFPIs could be dissolved in almost all organic solvents, even chloroform. The tensile strength and tensile modulus of these films were in the ranges of 78.6-85.7 MPa and 3.1-3.2 GPa, respectively. In addition, the polyimides displayed light color with special fluorescent and resistive switching(ON-OFF) characteristics; the maximum fluorescence emission was observed at 422-424 nm in NMP solution and at 470-548 nm in film state. The memory devices with the configuration of indium tin oxide/WuFPIs/aluminum(ITO/WuFPIs/Al) exhibited distinct volatile memory characteristics of static random access memory(SRAM), with an ON/OFF current ratio of 10~5-10~6. These functional polyimides showed attractive potential applications in the field of high performance flexible polymer photoelectronic devices or polymer memory devices.

负载生物活性功能基聚醚氨酯的表面自由能与表面血液相容性研究

利用 Captive bubble水相接触角技术对一系列负载生物活性功能基的聚醚氨酯溶液成膜后进行静态水相接触角研究 ,得到了材料 -水界面自由能γSW及其非极性部分γd SV和极性部分γpSV的贡献 .结果表明 ,对于负载不同生物功能基的聚醚氨酯 ,材料表面的水相静态接触角 θ以及 γSW、γd SV、γp SV与材料中 PEO含量有关 .对磺化 PEU,随材料本体和表面 PEO含量升高 ,γSW升高 .磺化 PEU的侧链末端分别接有 Lys或 Tyr可使γSW下降 .采用血小板粘附实验和凝血时间实验对合成的生物功能化抗凝血材料聚氨酯材料进行了初步的血液相容性研究 .结果表明 ,材料抗凝血能力与改性表面的表面能密切相关 ,负载生物活性功能基的聚醚氨酯具有预期的优良血液相容性 。

结构敏感功能材料的基础研究

结构敏感功能材料是其功能对原子的空间排列变化敏感的材料。通过对结构敏感功能材料的研究 ,归纳和总结化合物的物理化学性质与原子的空间排列以及电子结构之间的内在规律 ,结合物理化学性能测试和理论计算 ,逐步推导出功能基元和数学关系式 ,以形成功能基元理论 ,为开发新型功能材料提供理论基础。本文以碳原子不同的空间排列形式而展现出显著差异的物理化学性质为引子 ,阐述光学、电学和磁学性能对结构的敏感性 ,并讨论理论计算在该学科中的应用。

光响应生物材料研究进展及应用

目的:对光响应生物材料在药物控制系统及组织工程支架方面的研究及应用进行综述,为推进基础研究成果走向临床转化提供参考。方法:通过文献研究,归纳光响应生物材料的分类及光化学反应机理,讨论其在药物控制系统及组织工程支架领域中的应用,探讨其在临床转化中面临的挑战,并对未来发展方向进行展望。结果与结论:由于光源具有很多优点,使得光响应生物材料在药物控释系统、生物传感器、荧光探针及组织工程支架等生物医药领域得到广泛的关注。尽管近年来光响应生物材料基础理论研究已经取得巨大进展,但是在临床转化中仍存在激发光源和生物相容性等问题。未来新材料研发上如果能有创新,例如制备出对近红外光响应的生物材料或者兼具对多种刺激如光、pH、酶等有响应的生物材料,将会给光响应生物材料在医疗领域应用带来更大希望。

The impact of regiochemistry of conjugated molecules on the performance of organic electronic devices

Organic photovoltaics and field-effect transistors have attracted considerable attention due to the easy fabrication,low cost,light weight,and flexibility.Unsymmetrical conjugated building blocks are widely utilized for the design of new organic π-functional materials in order to achieve high-performance electronic devices,which has become a hot research topic in recent years.In this review,we summarized some typical organic π-functional materials with regioregular conjugated backbones with unsymmetrical electron-deficiency moieties and focused on the influence of regiochemistry on the final device performance.