Lewis-Acid-Catalyzed Interfacial Polymerization of Covalent Organic Framework Films
Lewis-Acid-Catalyzed Interfacial Polymerization of Covalent Organic Framework Films
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DOI：
10.1016/j.chempr.2017.12.011
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发表时间：
2018-02-08
期刊：
影响因子：
23.5
通讯作者：
Dichtel, William R.
中科院分区：
文献类型：
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作者：
Matsumoto, Michio;Valentino, Lauren;Dichtel, William R.
共价有机骨架 (COF) 是具有二维或三维共价键的结晶聚合物，提供直径为 1-5 nm 的孔。 COF 通常以微晶粉末形式分离，不适合许多利用其可调结构的应用，例如光电器件和纳滤膜。在这里，我们报道了多官能胺和醛单体与路易斯酸催化剂 Sc(OTf)(3) 的界面聚合。不混溶的溶液将催化剂与单体分离，将聚合限制在溶液界面。该方法提供了大面积、连续的COF薄膜（几cm(2)），厚度从100μm调整到2.5nm。相对较厚的薄膜是结晶的，而几纳米厚的薄膜可能是非晶态的。 COF 薄膜被转移到聚醚砜载体上，所得膜对罗丹明 WT（一种水污染物模型）的抑制能力增强。大面积、可调节的孔径和定制的分子组成显示出纳滤应用的前景。
Covalent organic frameworks (COFs) are crystalline polymers with covalent bonds in two or three dimensions, providing pores 1-5 nm in diameter. COFs are typically isolated as microcrystalline powders, which are unsuitable for many applications that would leverage their tunable structures, such as opto-electronic devices and nanofiltration membranes. Here, we report the interfacial polymerization of polyfunctional amine and aldehyde monomers with a Lewis acid catalyst, Sc(OTf)(3). Immiscible solutions segregate the catalyst from the monomers, confining polymerization to the solution interface. This method provides large-area, continuous COF films (several cm(2)) with a thickness tuned from 100 mu m to 2.5 nm. Relatively thick films were crystalline, whereas the films that are a few nanometers thick were presumably amorphous. The COF films were transferred onto polyethersulfone supports, and the resulting membranes showed enhanced rejection of Rhodamine WT, a model water contaminant. The large area, tunable pore size, and tailored molecular composition show promise for nanofiltration applications.