• 文献标题:   Lyotropic Liquid Crystal of Polyacrylonitrile-Grafted Graphene Oxide and Its Assembled Continuous Strong Nacre-Mimetic Fibers
  • 文献类型:   Article
  • 作  者:   LIU Z, XU Z, HU XZ, GAO C
  • 作者关键词:  
  • 出版物名称:   MACROMOLECULES
  • ISSN:   0024-9297 EI 1520-5835
  • 通讯作者地址:   Zhejiang Univ
  • 被引频次:   84
  • DOI:   10.1021/ma400681v
  • 出版年:   2013

▎ 摘  要

Liquid crystals (LCs) of pristine graphene made (GO), a kind of novel two-dimensional (2D) macromolecule, have been discovered recently, opening an avenue to high performance neat graphene fibers. Here, we report for the first time LC of polymer-grafted GO and its macroscopic assembled nacre-mimetic composite. Polyacrylonitrile (PAN) chains were covalently and uniformly grafted onto GO surfaces via a simple free radical polymerization process. The PAN-grafted GO (GO-g-PAN) sheets were well dispersed in Polar organic solvents. such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), forming nematic and lamellar LCs upon increasing concentration. A strong signal was found in the circular dichroism spectra of the LCs, indicating the formation of helical lamellar structures for the GO-g-PAN LCs. Macroscopic assembled fibers were continuously spun from the GO-g-PAN LCs via the industrially viable wet-spinning technology. The fibers held strict layered structures of GO and PAN, resembling the classic "brick-and-mortar" microstructure observed in nacre. The nacre-mimetic composite showed excellent mechanical property with tensile strength of 452 MPa, Young's modulus of 8.31 GPa, and breakage elongation of 5.44%. This offers a new approach for the fabrication of continuous, ultrastrong, and tough biomimic composites.