Direct α‐Alkylation of Aldehydes by Brønsted‐Acid Catalysis

A Brønsted acid catalyzed direct alkylation reaction of aldehydes was described. The 3,5‐dinitrobenzoic acid promoted the reaction between aldehydes and diarylmethanols to afford the corresponding alkylation products with middle to high yields (up to 91% yield).     

邻羧基苯甲醛水杨酰腙的合成及性质研究

以水杨酰肼和邻羧基苯甲醛为原料,合成了化合物邻羧基苯甲醛水杨酰腙(C15H12N2O4),对其进行了元素分析,IR,1HNMR表征和X射线单晶衍射结构分析.晶体属单斜晶系,C2/c空间群,晶胞参数为:a=19.352(8),b=14.219(8),c=12.762(3),β=115.605(14)°,V=3167(3)3,Z=8,F(000)=1344,Dc=1.344Mg/m3.该化合物分子通过两个苯环间的氢键作用(N—H…O)缠绕成了一个无限双螺旋链.热重实验表明该化合物的热分解过程可分为两个阶段,第二阶段的分解峰温值为232.64℃.初步生化活性实验结果显示,该化合物对大肠杆菌具有良好的抑、抗菌活性.     

A Self‐Assembly Approach to Temperature‐Responsive Polymer Nanocontainers

Summary: Thermosensitive polymer nanocontainers were formed by self‐assembly of diblock copolymers poly(2‐cinnamoylethyl methacrylate)‐block‐poly(N‐isopropylacrylamide) (PCEMA‐block‐PNIPAM) and subsequent photo‐crosslinking of the PCEMA shells. It was found that the diameter of the nanocontainers ranges from tens of nanometers to thousands of nanometers, depending on the self‐assembly conditions. The phase transition of the nanocontainers takes place at 32 °C; the structural changes are reversible in a heating and cooling cycle.

Schematic illustration of the structural transition behavior of the thermosensitive polymer nanocontainers.     

智能型分离膜研究

膜材料的智能化已成为当今分离材料领域发展的一个新方向。本文对智能型分离膜的各种制备方法进行了比较和分析,从其环境敏感特性方面对智能型分离膜的可控机理、可控性能进行了较为详细的综述,并简要介绍了智能型分离膜的表征方法。     

BaCO3纳米晶的固相反应合成及表征

纳米材料的研究与应用是当前物理、化学和材料科学的一个活跃领域［１］．合成纳米材料有多种方法,但反应均需高温,使用大量有机溶剂,过程控制复杂,设备费用高,颗粒均匀性差,粒子易粘结或团聚等［２］．室温、近室温固相反应近年来取得了很大进展［３,４］,它的突出优点是操作方便,合成工艺简单,转化率高,粒径均匀,且粒度可控,污染少,可避免或减少液相中易出现的硬团聚现象,以及由中间步骤和高温反应引起的粒子团聚现象．固相化学反应过程包括扩散反应成核生长４个阶段,当产物成核速度大于核生长速度时,有利于生成纳…