木材-石墨烯复合材料的制备及其三维导电性能

Preparation of Wood-based Graphene Material and Its Three-dimensional Electrical Conductivity

通过脉冲式真空浸渍的方法将氧化石墨烯(GO)与北京杨(Populus beijingensis)进行有机结合,制备木材-石墨烯三维导电材料;测试分析了制备材料的导电、电磁屏蔽、吸波的性能,从多角度表征材料的导电机理。结果表明:当氧化石墨烯质量浓度为4 g/L、炭化温度为750℃、炭化时间为30 min时,制备的木基石墨烯导电材料的三维各向异性导电性能最好,其纵向、弦向、径向的体积电阻率分别为0.641、2.153、2.932Ω·cm;此工艺条件时,木基石墨烯导电材料的电磁屏蔽效能达到40 dB、吸波强度达到-12 dB。材料的结构形貌表征结果表明,与同等条件炭化木材相比,木基石墨烯复合材料的碳氧质量分数比(w(C)∶w(O))显著提高,碳层排列有序;氧化石墨烯与木材结合程度较好;材料的热稳定性提高。说明氧化石墨烯在木材机体内部被充分还原为具有导电性能的还原氧化石墨烯,材料具有良好的导电性。

In order to give wood electrical conductivity,graphene oxide(GO)was organically combined with Populus beijingensis to prepare wood based graphene three dimensional conductive material by pulse vacuum impregnation.The conductive,electromagnetic shielding and absorbing properties of the material were tested and analyzed,and the conductive mechanism of the material was characterized from multiple angles.The three-dimensional anisotropic conductivity of the wood based graphene conductive material was the best when the mass concentration of GO was 4 g/L,the carbonization temperature was 750℃,and the carbonization time was 30 min.The volume resistivity of the material in longitudinal,tangential and radial directions are 0.641,2.153 and 2.932Ωcm,respectively.The electromagnetic shielding effectiveness of the wood based graphene conductive material reached 40 dB and the microwave absorption strength reached-12 dB.The structure and morphology of the material was characterized.Compared with the carbonized wood under the same conditions,the carbon oxygen content of graphene conductive material(w(C)∶w(O))is significantly increased,the carbon layer is arranged orderly,GO is well combined with wood,and the thermal stability of the material is improved.GO is fully reduced to reduced graphene with electrical conductivity in the wood body,and the material has good electrical conductivity.