关键词: 氮掺杂氧化石墨烯, 质量增重率, 阻燃, 表面比电阻, 服用性能

Abstract: Graphene has good thermal, electrical, and mechanical machinability, and the special boundary effect also gives graphene a controllable two-dimensional material surface, making it an ideal flame retardant, thermal insulation and conductive material. The defect is that the band gap of graphene is zero, the valence band and conduction band are difficult to open in the Brillouin zone, and the internal resistance caused by the accumulation of graphene sheets is large, which hinders the exploitation of graphene's electrical properties. Nitrogen atom doping can regulate the microstructure and electrical conductivity of graphene. By preparing nitrogen-doped graphene oxide, nitrogen-doped graphene dispersion and graphene oxide dispersion were used for the load modification of cotton fabrics. The micro-morphology, mass gain rate, limiting oxygen index, surface specific resistance, breaking strength bending stiffness and air permeability of the modified cotton fabric loaded by the two kinds of dispersion were tested and analyzed. The aim was to develop fabrics with composite functions such as flame retardancy and conductivity The results showed that the optimum loading concentration of nitrogen-doped graphene oxide / graphene oxide dispersion on cotton fabric is 6 g/L. Under the concentration, with the increase in load modification times, the coating on the surface of the cotton fabrics became increasingly denser, the mass gain rate, limiting oxygen index, breaking strength and flexure stiffness all increased, while the surface specific resistivity and air permeability showed a decreasing trend. The above test indicators increased as the number of load modifications rose, and when the number of load modification reached a certain number, the indicators tended to stabilize. When the cotton fabrics modified seven times with the loading modification were washed, the mass gain rate, limiting oxygen index, breaking strength and bending stiffness of the cotton fabrics modified by loaded modification decreased, while the surface specific resistance and air permeability were increasing. The indicators after four washing times were roughly equivalent to those of one load modification. At the same time, it could be seen from the test results that the crosslinking stability of cotton fabrics modified by nitrogen-doped graphene oxide was superior to that of cotton fabrics modified by graphene oxide, so the weight gain rate, limiting oxygen index, breaking strength and bending stiffness of cotton fabrics modified by nitrogen-doped graphene dispersion liquid were better than those of cotton fabrics modified by graphene, and the surface specific resistance and air permeability were worse than those of graphene-loaded modified cotton fabrics. It is concluded that using KH550 as crosslinking agent, it is feasible to develop composite functional fabrics by modifying cotton fabrics with dispersion liquid (nitrogen-doped graphene oxide/graphene oxide).

Key words: nitrogen-doped graphene oxide, mass gain rate, flame retardant, surface specific resistance, wear properties