石墨烯/碳纳米管复合纳米材料改性导电涂料的性能

Preparation and Characterization of rGO-PPD-MWCNT Hybrid Nano-Composites for Modifying Conductive Coatings

为提高接地网导电涂层的导电性及防腐蚀蚀性,采用对苯二胺(PPD)对氧化石墨烯(GO)进行还原改性后与多壁碳纳米管(MWCNT)进行化学接枝,制备了rGO-PPD-MWCNT复合纳米材料;并将此作为导电填料填充到以环氧树脂为基质的涂料中,制备了一种新型的导电涂料。以傅里叶红外光谱仪(FTIR)、X射线粉末衍射仪(XRD)、扫描电镜(SEM)研究了复合纳米材料的形貌特征;以电化学方法研究了石墨烯与碳纳米管质量比变化时复合纳米导电涂层导电率、阻抗等的变化特性。结果表明:rGO-PPD-MWCNT复合纳米材料具有良好分散性与协同效应,显著提高了环氧涂层的导电性、防腐蚀性,当PPD还原改性的氧化石墨烯(rGO-PPD)与MWCNT质量比为1∶3时,复合纳米导电涂层体积电阻率为1.90×10-4Ω·m;本质原因在于化学接枝结构有利于碳纳米管和石墨烯的分散,且碳纳米管支架作用防止了石墨烯片层的重新堆叠,由此增加了其导电性。

In order to improve the electrical conductivity and corrosion resistance of grounding-grid conductive coatings,graphene oxide(rGO)was modified with reduction by p-phenylenediamine(PPD)and then joined with multiwalled carbon nanotubes(MWCNTs)via chemical grafting to obtain rGO-PPD-MWCNT nanomaterials.Subsequently,the nanomaterials were used as conductive fillers to fill the coatings with epoxy as matrix,and thereby a new kind of conductive coating was obtained.The morphology of samples was studied by Fourier transform infrared spectroscopy(FTIR),X-ray powder diffractometer(XRD)and scanning electron microscopy(SEM),and the changes of conductivity and impedance of the nanomaterial with different ratios of rGO to MWCNT were studied by electrochemical method.Results showed that the rGO-PPD-MWCNT hybrid material possessed good dispersibility and synergistic effect,which could significantly improve the electrical conductivity and corrosion resistance of the epoxy coating.When the ratio of rGO-PPD to MWCNT was 1∶3,the volume resistivity of obtained coating was 1.90×10-4Ω·m.The essential reason was that the chemical graft structure facilitated the dispersion of carbon nanotubes and rGO,and the carbon nanotube scaffolding prevented the re-stacks of the rGO sheets,thereby increasing their electrical conductivity.