Fabrication And Stretching Of Ionic Liquid Crosslinked Graphene Oxide Fibers And The Study Of Their Performance

Graphene,a flat monolayer of carbon atoms tightly packed into a two-dimensional honeycomb lattice,has received persistent attention due to its fascinating properties,such as electronic conductivity,high thermal conductivity,and extraordinary elasticity and stiffness.The technique of integration graphene sheets into the macroscopic structures is no doubt very useful since it is an essential step to explore the practical applications of these nanosheets with unique properties.Graphene oxide(GO),produced by the oxidation and consequently exfoliation of graphite,can be viewed as a single monomolecular layer of graphite with various oxygen containing functionalities.The advantages of the GO is easy dispersability in water and other polar organic solvents,make it an ideal for the fabrication of graphene-based materials with various macroscopic architectures.graphene fibers(GFs),with graphene layers aligned along the fiber axis direction,have become one of the hotspot due to their potential application for flexible and wearable sensors or electronics.In this paper,the mechanical properties of GOFs have been controlled by selecting different ionic liquids,the research contents are as follows:1.GO fibers is prepared by wet spinning with aqueous dispersion of GO as spinning solution and aqueous solution of ionic liquid as solidifying liquid.The ionic liquids are 1-butyl-3-methylimidazolium lactate and 1-butyl-1-methyl pyrrolidinium bromide and the tensile strength of the fibers is 387.3 MPa and 304 MPa,respectively.The tensile strength of the fibers reduced by HI is 412.2 MPa and 357.2 MPa and the conductivity is 181.9 S/cm and 146.7 S/cm,respectively.We found that the fibers have good mechanical and electrical properties.The first ionic liquid can form electrostatic attraction and π–π stacking action with GOFs and the second only have electrostatic attraction,so the first has higher mechanical property than second.2.GO fibers is prepared by wet spinning with 1-aminopropyl-3-methylimidazolium bromide as the solidifying liquid.This ionic liquid can form covalent bonds with GO sheets.The tensile strength of the fibers is 480 MPa,which has higher tensile strength than fiber in 1.Based on the above,we can select different kinds of ionic liquids to control the mechanical properties of GO fibers.3.GO fibers is prepared by wet spinning with 1-butyl-3-methylimidazolium lactate as solidifying liquid,and then the fibers are stretched.The tensile strength of stretched fibers is 470 MPa,which is grently increased as compared to fibers in 1.Because strectching can reduce defects and increase orientation,the mechanical property of GO fibers is improved.