用户名: 密码: 验证码:
Step-by-step design of novel biomimetic nanoreactors based on amphiphilic calix[4]arene immobilized on polymer or mineral platforms for destruction of ecological toxicants
详细信息    查看全文
文摘
The effective supramolecular catalysts based on amphiphilic calix[4]arene functionalized by iso-nonyl groups at the upper rim and polyoxyethylene groups at the lower rim (9CO9) are developed for the destruction of toxic phosphorus acid esters. In the microheterogeneous 9CO9-polyethyleneimine (PEI)-lanthanum salt systems, a step-by-step enhancement of the catalytic activity was accomplished and a ca. 200-fold acceleration of hydrolysis is reached. The effect is contributed by the superposition of the factors of micellar catalysis (the concentration of reagents and changes in their microenvironment) and homogeneous catalytic mechanisms, in particular the general basic catalysis by aminogroups of PEI and the electrophilic catalysis by the La(III) ions. A further increase in the catalytic performance is achieved through the covalent immobilization of 9CO9 on the mesoporous silica. An inhibition/catalysis inversion occurs upon transferring from the single 9CO9 solution to the supported 9CO9@SiO2 particles.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700