文献类型：期刊文献

中文题名：环形偶氮苯功能化聚类肽的合成与自组装

英文题名：Synthesis and Self-Assembly of Azobenzene-Functionalized Cyclic Polypeptoids

作者：王永秀[1];赵崇浩[1];陶鑫峰[1];林绍梁[1]

机构：[1]华东理工大学材料科学与工程学院,上海市先进聚合物材料重点实验室,上海200237

年份：2024

卷号：37

期号：1

起止页码：5

中文期刊名：功能高分子学报

外文期刊名：Journal of Functional Polymers

收录：CSTPCD;;Scopus;北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金青年科学基金(21901073);上海市自然科学基金(19ZR1412100);上海市晨光计划(18CG32)。

语种：中文

中文关键词：偶氮苯;聚类肽;环形聚合物;自组装;光响应

外文关键词：azobenzene;polypeptoid;cyclic polymer;self-assembly;photo-responsivenes

摘要：首先采用1,8-二氮杂二环十一碳-7-烯(DBU)引发N-烯丙基甘氨酸-N-硫代羧酸酐(NAG-NTA)和N-乙基甘氨酸-N-硫代羧酸酐(NEG-NTA)开环聚合,制备环形结构的聚(N-烯丙基甘氨酸)-b-聚(N-乙基甘氨酸)(c-PNAG-b-PNEG)。然后通过聚合后修饰反应,在PNAG嵌段的双键上引入偶氮苯基团,合成了新型的环形偶氮苯聚类肽c-P(NAG-Azo)-b-PNEG。采用透射电子显微镜(TEM)和紫外-可见光谱(UV-Vis)研究了c-P(NAG-Azo)-b-PNEG在水溶液中的自组装行为和光响应特性,并与线形结构的l-P(NAG-Azo)-b-PNEG进行比较。结果表明,c-P(NAG-Azo)-b-PNEG和l-P(NAG-Azo)-b-PNEG可以组装得到球形胶束、树枝状聚集体和球形大复合胶束,并且它们均具有良好的光致顺反异构特性。环形结构限制分子链的运动,不利于偶氮苯基团的有序堆积,也会使c-P(NAG-Azo)-b-PNEG组装体的光致形貌转变程度减弱。
Cyclic block copolypeptoid poly(N-allylglycine)-b-poly(N-ethylglycine)(c-PNAG-b-PNEG)was synthesized through the 1,8-diazabicycloundec-7-ene(DBU)-initiated ring opening polymerization of N-allylglycine N-thiocarboxyanhydride(NAG-NAT)and N-ethylglycine N-thiocarboxyanhydride(NEG-NAT).Two different cyclic copolypeptoids,c-PNAG14-b-PNEG37 and c-PNAG27-b-PNEG31,were prepared and their compositions were confirmed by the proton nuclear magnetic resonance(1H-NMR).According to the gel permeation chromatography(GPC)traces,c-PNAG-b-PNEG showed a lager retention time compared to its linear counterpart l-PNAG-b-PNEG obtained by using benzylamine as the initiator,which verified the cyclic structure of c-PNAG-b-PNEG.Carboxyl(CA)-functionalized cyclic copolypeptoid c-P(NAG-CA)-b-PNEG was synthesized through the thiol-ene click reaction between mercaptoacetic acid(CA-SH)and c-PNAG-b-PNEG.And then azobenzene(Azo)-functionalized cyclic copolypeptoid c-P(NAG-Azo)-b-PNEG was synthesized by carboxyl-hydroxyl condensation between 3-(4-((4-butylphenyl)diazenyl)phenoxy)propanol(Azo-C3-OH)and c-P(NAG-CA)-b-PNEG.The quantitative modification was confirmed by the 1H-NMR spectra and GPC traces.c-P(NAG-Azo)14-b-PNEG37 self-assembled into irregular spherical micelles with a diameter around 50 nm in aqueous solution,while dendritic aggregates formed by stacked lamellar assemblies were observed in the case of l-P(NAG-Azo)16-b-PNEG38,which was attributed to the more disordered stacking of the Azo groups in the cyclic copolypeptoids.With the increasing chain length of P(NAG-Azo),both c-P(NAG-Azo)27-b-PNEG31 and l-P(NAG-Azo)30-b-PNEG25 self-assembled into large composite micelles with a diameter around 1—2μm due to the lager hydrophobic/hydrophilic ratio,which was also ascribed to the weaker motion restriction of longer chain length cyclic polymers.Both c-P(NAG-Azo)-b-PNEG and l-P(NAG-Azo)-b-PNEG showed excellent photo-isomerization,and the UV-Vis absorption of l-P(NAG-Azo)-b-PNEG assemblies exhibited a more obvious blue shift compared to the case of c-P(NAG-Azo)-b-PNEG assemblies,which meant Azo groups had a weaker H-type arrangement in the cyclic copolypeptoid assemblies.After irradiated by 365 nm light for 1 h,large composite micelles of c-P(NAG-Azo)27-b-PNEG31 swelled and partially disassembled,while the ones of l-P(NAG-Azo)30-b-PNEG25 completely disassembled.The cyclic structure restricted the chain motion leading to a lower trans-to-cis isomerization degree of c-P(NAG-Azo)27-b-PNEG31 assemblies.After being irradiated by 450 nm light for 2 h,large composite micelles were reformed again.