Sequential Block Copolymer Self-Assemblies Controlled by Metal–Ligand Stoichiometry

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• 作者：Liyuan Yin ; Hongwei Wu ; Mingjie Zhu ; Qi Zou ; Qiang Yan ; Liangliang Zhu
• 刊名：Langmuir
• 出版年：2016
• 出版时间：June 28, 2016
• 年：2016
• 卷：32
• 期：25
• 页码：6429-6436
• 全文大小：445K
• 年卷期：0
• ISSN：1520-5827

文摘

While numerous efforts have been devoted to developing easy-to-use probes based on block copolymers for detecting analytes due to their advantages in the fields of self-assembly and sensing, a progressive response on block copolymers in response to a continuing chemical event is not readily achievable. Herein, we report the self-assembly of a 4-piperazinyl-1,8-naphthalimide based functional block copolymer (PS-b-PN), whose self-assembly and photophysics can be controlled by the stoichiometry-dependent metal–ligand interaction upon the side chain. The work takes advantages of (1) stoichiometry-controlled coordination–structural transformation of the piperazinyl moiety on PS-b-PN toward Fe³⁺ ions, thereby resulting in a shrinkage–expansion conversion of the self-assembled nanostructures in solution as well as in thin film, and (2) stoichiometry–controlled competition between photoinduced electron transfer and spin–orbital coupling process upon naphthalimide fluorophore leading to a boost–decline emission change of the system. Except Fe³⁺ ions, such a stoichiometry-dependent returnable property cannot be observed in the presence of other transition ions. The strategy for realizing the dual-channel sequential response on the basis of the progressively alterable nanomorphologies and emissions might provide deeper insights for the further development of advanced polymeric sensors.