文献类型：期刊文献

中文题名：含偶氮苯侧链不对称分子刷聚合物的合成及其自组装研究

英文题名：Synthesis and Self-assembly of Asymmetric Molecular Brushes with Azobenzene-containing Side Chains

作者：姚远[1];何品[1];陶鑫峰[1];徐彬彬[1];林绍梁[1]

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

年份：2024

卷号：55

期号：4

起止页码：407

中文期刊名：高分子学报

外文期刊名：Acta Polymerica Sinica

收录：CSTPCD;;Scopus;WOS:【SCI-EXPANDED(收录号:WOS:001208589800003)】；北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金(基金号52073092,52273008,22001072);上海市自然科学基金(基金号23QA1402500,22ZR1479300,20CG38)资助项目。

语种：中文

中文关键词：分子刷;偶氮苯;捆状组装体;光响应性;自组装

外文关键词：Molecular brushes;Azobenzene;Sheaf-like aggregate;Photo-responsiveness;Self-assembly

摘要：设计合成了含有2-羰基溴和烷基氯基团的功能性丙烯酸酯单体(Br-acrylate-Cl),利用可逆加成断裂链转移(RAFT)聚合得到大分子试剂poly(Br-acrylate-Cl).首先通过poly(Br-acrylate-Cl)引发偶氮苯丙烯酸酯单体(Azo)的原子转移自由基聚合(ATRP),然后用取代反应接入六甘醇修饰的四苯乙烯(OH-TPE-HEG),合成了同时含有偶氮苯侧链、四苯乙烯侧基和六甘醇侧链的不对称分子刷聚合物PA-g-PAzo/(TPE-HEG).偶氮苯侧链和四苯乙烯侧基的π-π相互作用和有序堆积,赋予了PA-g-PAzo/(TPE-HEG)组装体规整的分子排布.系统研究了PA-g-PAzo/(TPE-HEG)在甲醇/四氢呋喃混合溶剂中的自组装行为,得到了束状、捆状和片状等形貌组装体,并探究了捆状组装体的形成过程以及组装体的光响应形貌调控.本文的研究不仅提供了构建不对称分子刷聚合物的新合成方法,还丰富了分子刷组装体的种类.
Self-assembly of amphiphilic copolymers presents a promising platform for the design and synthesis of nanomaterials,depending heavily on the topological polymer chemistry and properties of their compositions.In particular,asymmetric molecular brushes are composed of two different side chains grafted on a linear backbone,possessing distinct assembly behaviors in comparison with conventional linear copolymers,owing to the asymmetric double-brushes and combined effects of backbone and brushes.Additionally,the introduction of unique functionalities and responsiveness into the self-assembly system of asymmetric molecular brushes endows extra opportunities to pursue morphologic diversity and intriguing functionalities.In this study,a novel functional acrylate monomer Br-acrylate-Cl with Br-containing initiating group and alkylchlorine group was designed and synthesized.The functional macro-agent,poly(Br-acrylate-Cl),was first prepared by reversible addition-fragmentation chain transfer(RAFT)homopolymerization of Br-acrylate-Cl monomer.Azobenzene-containing side chains were then directly grown from the backbone via atom transfer radical polymerization(ATRP)of azobenzene-containing monomer initiated by the pendant Br-containing initiating groups on the backbone,affording PA-g-PAzo molecular brushes.The obtained PA-g-PAzo molecular brushes were subsequently used in postpolymerization substitution to generate PA-g-PAzo/(TPE-HEG)asymmetric molecular brushes with azobenzene and hexaethylene glycol-containing side chains and tetraphenylethylene groups.Due to the special architecture and inter/intramolecular association of pendant azobenzene and tetraphenylethylene groups,PA-g-PAzo/(TPE-HEG)asymmetric molecular brushes exhibited unique self-assembly behavior.Therefore,π-πand solvophobic interaction-driven self-assembly of PA-g-PAzo/(TPE-HEG)in CH3OH-THF mixed solvents was studied,and the morphologies of the assemblies were characterized by transmission electron microscopy(TEM).Well-defined bundle-like aggregates,sheaf-like aggregates,and 2D platelets were constructed via self-assembly of PA-g-PAzo/(TPE-HEG)through a heating-cooling-aging process.The formation of sheaf-like aggregates was systematically investgated.Intriguingly,the azobenzene moieties undergo trans-cis isomerization upon UV irradiation and further promote a morphology evolution of the assemblies,leading to the formation of rectangular platelets.Our study presents an efficient method for preparing asymmetric molecular brushes based on the functional monomer stragtegy,and opens a new avenue to design molecular-brush-based nanomaterials with tunable morphologies.