Hybrids of silver nanowires and silica nanoparticles as morphology controlled conductive filler applied in flexible conductive nanocomposites

Flexible conductive polymer nanocomposites based on silver nanowires (AgNWs) have been widely studied to develop the next generation of flexible electronics. However, AgNWs tend to aggregate in polymer matrix that usually results in high percolation threshold. In this study, nonconductive silica nanoparticles (nano-SiO2) were successfully co-assembled on AgNWs to form AgNWs/nano-SiO2 hybrids and waterborne polyurethane (WPU) conductive nanocomposites filled with the hybrids were prepared. The results show that the resistivity of WPU nanocomposites filled with AgNWs/nano-SiO2 hybrids decreased about 5000 times and the percolation threshold decreased from 10.6 vol% to 3.6 vol% due to AgNWs distribute more uniformly in WPU with the help of nano-SiO2. The further study to mechanism of interactions between AgNWs and nano-SiO2 suggest that the promotion of dispersion is attributed to hydrogen bonding and van der Waals force. The WPU nanocomposites embedded with AgNWs/nano-SiO2 hybrids present excellent mechanical adhesiveness, flexibility and thermal stability.