Purification of 2,6-Diisopropylnaphthalene by Static Melt Crystallization from a Mixture Containing Diisopropylnaphthalene Isomers

2,6-Diisopropylnaphthalene （2,6-DIPN）, as the precursor of important monomer 2,6-naphthalene dicarboxylic acid, could be produced by the shape-selective isopropylation of naphthalene with propene resulting in an isomeric mixture having different alkylation levels. Since the boiling points of DIPNs were very close and the differences of melting points in-between isomers were quite distinctive, the static melt crystallization was applied to separate and purify 2,6-DIPN from its isomers. 2,6-DIPN with purity ≥99% was produced through a process of three stages： crystallization→sweating→melting. The phase diagram of 2,6-DIPN-2,7-DIPN binary system was plotted to opti- mize the temperature control of crystallization. By repeated crystallization of melts with different concentration levels, the yield of pure 2,6-DIPN could be enhanced to 87%. No solvent was necessary. Keywords 2,6-diisopropylnaphthalene, static melt crystallization, crystallization rate, sweating rate, eutectic temperature     

聚六亚甲基单胍盐酸盐黏均相对分子质量的测定及抑菌效果

采用黏度法测定新型高分子聚合物杀菌消毒剂--聚六亚甲基单胍盐酸盐的平均相对分子质量。聚六亚甲基单胍盐酸盐溶液浓度在0.04 g/mL时,利用文献值K=3.8×10-3 g/mol、α=1.01,可计算出该自制的聚六亚甲基单胍盐酸盐的平均相对分子质量为2495。在相同的浓度下,不同相对分子质量的聚六亚甲基单胍盐酸盐对大肠杆菌、金黄色葡萄球菌、白色葡萄球菌和铜绿假单胞菌均有一定的抑菌作用,并且抑菌效果均随着相对分子质量的增加而增加。     

基于三苯胺的增强型Fe3+荧光探针及性能

Fe3+在人的许多生理过程中扮演着重要的角色,例如氧气运输、DNA合成、髓磷脂合成、线粒体呼吸、神经递质合成和代谢等.然而,过量的Fe3+会诱导细胞产生·OH从而引起细胞损伤,并且还会诱导β-地中海贫血、帕金森病、癫痫和阿尔茨海默病等疾病的发生.因此,对Fe3+的检测和监测具有非常重要的意义.本文设计并合成了一种以三苯...     

洛美沙星对映体在Chiralcel OJ柱上的拆分机理

提出了洛美沙星对映体的高效液相色谱拆分方法。选用Chiralcel OJ手性柱,正己烷-异丁醇(90+10)的混合溶液为流动相,流量为0.6mL·min~(-1),柱温为30℃,检测波长为287nm。通过溶质计量置换保留模型和热力学理论对Chiralcel OJ手性柱拆分机理进行了探讨。结果表明:保留时间较短的洛美沙星对映体的lgI值和Z值均小于保留时间较长的对映体。在试验的温度范围内,用1nα对1/T作图,得到Van't Hoff曲线呈线性关系,焓变和熵变之差为负值,说明手性拆分过程为焓控过程。