原位法制备纳米银修饰碳纳米管环氧导电复合材料

将碳纳米管(CNTs)和乙酸银同时引入到环氧树脂-咪唑固化体系中,在固化过程中原位热降解银-咪唑复合物生成纳米银修饰碳纳米管,差示扫描量热仪(DSC)表明改性碳纳米管对环氧固化有一定的促进作用.采用X-射线衍射(XRD)表征了乙酸银和咪唑配合物[Ag(2E4MZ)2]Ac的结构,并提出了原位降解生成纳米银的机理.XRD结果表明,单独的乙酸银-咪唑配合物热降解生成的纳米银粒径为21-24nm,而配合物在环氧基体中生成的纳米银粒径为11-13nm.添加80%(质量分数)片状微米银粉制备的纳米银/碳纳米管环氧导电复合材料其体积电阻率低达9×10-5Ω·cm.当纳米银和碳纳米管质量比为80:20时,复合材料导电性和剪切强度达到最佳;采用扫描电镜(SEM)表征了复合材料的形貌结构.

In situ Preparation of Epoxy-Based Conductive Nanocomposites Containing Nanosilver-Decorated Carbon Nanotubes

Nanosilver-decorated carbon nanotubes(CNTs)were prepared by introducing CNTs and silver acetate into an epoxy-imidazole curing system and simultaneous in situ thermal degradation of an Ag-imidazole complex.Differential scanning calorimetry(DSC)results indicated that modified CNTs played a certain role in promoting the curing of the epoxy.The structure of the silver acetate-imidazole complex was characterized by X-ray diffraction(XRD).The size of the nano-silver particles resulting from degradation of the Ag-imidzole complex was between 21 and 24 nm,and between 11 and 13 nm when the Ag-imidzole complex was added to the epoxy matrix.When silver flakes with a mass fraction of 80%was added to the composites,the volume resistivity of the nanosilver-decorated CNTs/epoxy conductive composite was as low as 9×10 -5 Ω·cm.The optimum conductivity and shear strength were achieved when the ratio of nanosilver and CNTs was 80:20(mass ratio).Scanning electron microscopy(SEM)revealed the structural morphology of the composite.