Trimethyltriazine-derived olefin-linked covalent organic framework with ultralong nanofibers  

基于2,4,6-三甲基-1,3,5-三嗪的超长纳米纤维状乙烯基桥连共价有机框架

作　　者：Fan Zhang Shice Wei Weiwei Wei Jiang Zou Guoying Gu Dongqing Wu Shuai Bi Fan Zhang 张凡;魏士策;魏巍巍;邹江;谷国迎;吴东清;毕帅;张帆(School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Robotics Institute,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [2]Robotics Institute,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [3]State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Science Bulletin》2020年第19期1659-1666,M0004,共9页科学通报（英文版）

基　　金：the National Natural Science Foundation of China(21774072,and 21720102002);financially supported by the Open Project Programs of the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(2019-01,Jilin University);the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2019,Donghua University)。

摘　　要：Two-dimensional(2D)olefin-linked covalent organic frameworks(COFs)with excellentπ-electron communication and high stability are emerging as promising crystalline polymeric materials.However,because of the limited species of COFs,their characteristics,processability and potential applications have not been completely understood and explored.In this work,we prepared two novel olefin-linked 2D COFs through Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with tritopic triazine-cored aldehydes.The resulting COFs exhibit highly crystalline honeycomb-like structures stacked from hexagonallatticed polymeric layers and display well-defined nanofibrillar morphologies with the uniform diameters of ca.80 nm and ultra-lengths up to several micrometers.Such COF nanofibers can be readily composited with carbon nanotubes into high-quality continuous thin films,which are further compacted by a typical hot-pressing process to enhance their densities and mechanical strength without changing their fibrous microstructures.Such film-fabricated interdigital microelectrodes and the ionogel electrolyte are assembled into planar micro-supercapacitors(MSCs),which exhibit an outstanding areal capacitance of 44.3 mF cm^-2,large operating voltage window of 2.5 V,high volumetric energy density of 38.5 mWh cm^-3 as well as excellent cycling stability.二维乙烯基桥连共价有机框架材料(COF)因具有良好的π电子离域属性和超高的化学稳定性而成为一类极具研究价值的低维晶态聚合物材料,但受限于种类较少,其各种物性、可加工性和潜在应用仍处于探索阶段.本文以2,4,6-三甲基-1,3,5-三嗪为关键单体,与基于三嗪核的三倍对称性芳香多醛类单体在氢氧化钾催化下通过Knoevenagel缩聚合成了两种新型乙烯基桥连二维COF材料.两种COF材料均显示出较高结晶性并呈现蜂窝状六边形孔道结构,同时它们可形成确定的纳米纤维形貌,其直径约为80 nm,长度可达几微米.这类COFs纳米纤维能够与碳纳米管组装复合成高质量薄膜,通过传统的热压工艺处理,在不改变其微纳结构的前提下进一步提高了薄膜的密度和机械强度.随后,将该复合薄膜利用激光刻蚀法加工成微型叉指电极,并与离子液体固态电解质进一步组装成平面微型超级电容器.该器件在2.5 V电压窗口下,展现出44.3 mF cm^-2面积电容、38.5 mWh cm^-3能量密度以及良好的循环稳定性.

关 键 词：Covalent organic framework Olefin linkage NANOFIBER Micro-supercapacitor Energy storage 

分 类 号：TQ317[化学工程—高聚物工业]