Coating carbon nanotubes with silver nanoparticles to get conductive nanocomposites

A simple approach for coating carbon nanotubes (CNTs) with silver nanoparticles was developed in this work, aiming to enhance the electrical conductivity of CNTs. To coat Ag nanoparticles on CNTs (Ag@CNTs) effectively, CNTs were treated using ball milling with addition of ammonium bicarbonate, followed by reduction of silver ions in N,N-dimethylformamide (DMF). Transmission electron microscope (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were employed to characterize the changes of CNT surface and loading of Ag on CNTs, respectively. Then the Ag@CNTs were employed as conductive fillers in epoxy resin to get conductive nanocomposites. The electrical and mechanical properties of the nanocomposites were investigated and compared with those containing pristine CNTs (P-CNTs). It was found that the electrical conductivity of nanocomposites containing Ag@CNTs was significantly higher than those containing PCNTs, confirming the advantage of the Ag@CNTs as effective conductive filler. The mechanical properties were similar between those nanocomposites containing Ag@CNTs and P-CNTs. The implications of the findings on electrical and mechanical properties were discussed regarding perspective applications of this conductive filler in electrical packaging industry.