摘 要：新型組裝基元的構(gòu)筑和組裝體的功能是自組裝研究的兩個(gè)核心問題。該研究分別在這兩個(gè)方面取得了一些進(jìn)展。各向異性組裝基元的出現(xiàn)極大地豐富了自組裝的研究內(nèi)容，并為制備高度有序和復(fù)雜的組裝體提供了新工具，但目前已報(bào)道的各向異性組裝基元一般限于微觀和亞微觀尺寸。該研究制備了分子水平的各向異性粒子，并發(fā)現(xiàn)其具有獨(dú)特的自組裝行為。比如：合成了分別具有一個(gè)環(huán)糊精基團(tuán)和一個(gè)偶氮苯基團(tuán)的超支化聚合物，然后通過環(huán)糊精和偶氮苯之間的主客體復(fù)合，偶聯(lián)得到了Janus型超支化聚合物，且該各向異性聚合物可以進(jìn)一步自組裝形成均一的納米囊泡，而且所制備的囊泡可以進(jìn)一步組裝形成類似膠子晶體的多級結(jié)構(gòu)。這種高度均一的囊泡組裝體是十分罕見的。該課題還在組裝體的功能化方面開展研究。例如：長期以來仿細(xì)胞模型體系一般只限于對細(xì)胞膜結(jié)構(gòu)的仿生，但實(shí)際上細(xì)胞在發(fā)生結(jié)構(gòu)轉(zhuǎn)變時(shí)往往伴隨著功能的表達(dá)。最近，我們制備了具有pH響應(yīng)的聚合物囊泡，該囊泡可以在pH觸發(fā)下實(shí)現(xiàn)可逆的收縮和膨脹，最為重要的是在這個(gè)形變過程中，同時(shí)伴隨著囊泡熒光的增強(qiáng)和淬滅。整個(gè)過程和綠色熒光水母的呼吸過程有些相似。這是目前已報(bào)道的為數(shù)不多的結(jié)構(gòu)和功能同時(shí)表達(dá)的一個(gè)人工模型膜體系。

關(guān)鍵詞：自組裝 各向異性粒子 超支化聚合物 囊泡 細(xì)胞模擬

Abstract： It is centrally important for self-assembly research to construct new building blocks and attain new functionalities. We made some progress in these two topics in 2013. Anisotropic particles are new building blocks for self-assembly， which greatly enrich the scope of self-assembly and provide a new toolbox to construct highly ordered and complex self-assemblies. However， most of the reported anisotropic particles are limited in microscopic or submicroscopic scale. Recently， we have extended it into the molecular level， and found new self-assembly behaviors can be realized from these building blocks. For instance， we constructed a Janus hyperbranched polymer by the noncovalent coupling between a hydrophobic hyperbranched poly（3-ethyl-3-oxetanemethanol） with an apex of an azobenzene （AZO）group and a hydrophilic hyperbranched polyglycerol with an apex of a β-cyclodextrin （CD） group through the specific AZO/CD host？guest interactions. This amphiphilic supramolecular polymer can further self-assemble into unilamellar bilayer vesicles with narrow size distribution， which could further aggregate into colloidal crystal-like close-packed arrays under freeze-drying conditions. Such a well-defined and uniform vesicle structure has seldom been observed. Besides， we also focused on the functionalities of self-assemblies. For example， in cytomimetic chemistry， most of the works are concentrated on the structure mimics of cells but seldom involve the functionalities therein. Recently， we produced a pH-responsive polymer vesicle through the aqueous self-assembly of an amphiphilic diblock copolymer consisting of many fluorescent chromophores of dimethylaminoazobenzene. They exhibited pH-responsive breathing behavior involving the swelling and shrinkage of the vesicles. Furthermore， in analogy with jellyfish， the fluorescence is quenched when the vesicles breathe in， whereas a strong green fluorescence is emitted when the vesicles breathe out. Such a cytomimetic behavior in combination with the structure and functionality express has seldom been observed before.

Key Words： Self-assembly； Anisotropic particles； Hyperbranched polymers； Vesicles； Cytomimetic chemistry

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