聚丙烯表面的生物相容性修饰: 表面氨基放大还原胺化接枝磷酰胆碱

在氨气氛中对聚丙烯薄膜表面进行等离子处理, 获得了不同浓度的表面氨基. 表面氨基的数量经1,6-己二异氰酸酯键合三(2-氨乙基)胺可成倍增加. 用还原胺化法将磷酰胆碱醛共价接枝到表面氨基上获得了磷酰胆碱改性的聚丙烯薄膜. X射线光电子能谱(XPS)测定结果表明, 接枝磷酰胆碱基团的表面覆盖率可达20%～40%. 衰减全反射傅立叶变换红外(ATR-FTIR)和动态接触角测定结果也都说明磷酸胆碱基团被成功地接枝于聚丙烯表面. 还原胺化法结合等离子处理及表面氨基放大技术, 有望成为获取新型生物材料的一种有效途径.     

Reaction du meta-diisopropyl-phenyllithium-chrometricarbonyle avec le monoxyde de carbone

The complex CpV(CO)₃THF has been prepared in THF solution (i) photochemically from CpV(CO)₄, and (ii) from [CpV(H)(CO)₃]^?/[Ph₃C]⁺ at low temperatures. THF is replaced by [CpV(H)(CO)₃]^? to form [{CpV(CO)₃}₂-μ-H]^?, and by various ligands L with C, η²-CC, Sn, N, O, S, Se or Te functionality to yield CpV(CO)₃L and cis-[CpV(CO)₂LL] (LL = bipy, o-phen, tolane). The δ (⁵¹V) values range over ca. 1400 ppm and allow the assignment of distinct coordination modes for ambidentate ligands. The temperature gradient is ca. +1.2 ppm/deg. For [CpV(SnCl₃)(CO)₃]^? (δ ?1340 ppm rel. to VOCl₃), ¹J(⁵¹V-^117,119Sn) is 900 Hz. The isotope effect on introducing ¹²CO for ¹³CO in CpV(CO)₄ is ?0.48(2) ppm; ¹J(⁵¹V-¹³C) 107 Hz.     

The synthesis of low melting liquid crystalline lanthanide complexes with triflate counter-anions

Paramagnetic liquid crystalline complexes of the formula [LnL(LH)₂][CF₃SO₃]₂ have been synthesised, where LH is the ligand N-dodecyl-4-(3',4'-didodecyloxybenzoyloxy)salicylaldimine and Ln is a lanthanide metal. When compared with analogous nitrate complexes, the transition temperatures are rather low.     

LiFePO<Subscript>4</Subscript> synthesized via melt synthesis using low-cost iron precursors

LiFePO₄/C material has been prepared using fast-melt synthesis method followed by grinding and carbon coating. The low-cost iron ore concentrate (IOC) and purified iron ore concentrate (IOP) were used as iron precursors in the melt process to reduce significantly the cost of LiFePO₄/C. The same product was also synthesized using pure Fe₂O₃ under similar conditions as reference. The physical-chemical and electrochemical properties of samples were investigated. The X-ray Diffraction (XRD) results confirm the formation of an olivine structure of LiFePO₄ with a minor amount of Li₃PO₄ and Li₄P₂O₇ impurities for all the samples but no Fe₂P. The power performances of LiFePO₄/C using low-cost iron precursors were close to the sample using pure Fe₂O₃ precursor although capacity in mAh g^?1 is somewhat lower. With the inherent presence of silicon and other metals species, multi-substitution may take place when using IOC as source of iron leading to a Li(Fe_1-yM_y)(P_1-xSi_x)O₄ general composition. Multi-substitution, however, allows a better cycling stability. Therefore, these iron precursors present a promising option in this field to reduce the cost of a large-scale synthesis of LiFePO₄/C for Li-ion batteries application.