Effects of gold nanoparticles and lithium hexafluorophosphate on the electrical conductivity of PMMA

An increase in electrical conductivity of a polymeric system can be realized by adding conductive fillers and/or dissolving a salt in a suitable solvent or polymer through formation of ionic conduction. An appropriate solvent that can form complexes with alkali metal cations is critical to providing electrical conductivity enhancements to a wide variety of polymers. In this study, we investigated the effects on electrical conductivity of lithium hexafluorophosphate (LiF6P) through the use of butyl glycidyl ether (BGE) as the solvent for dissolving the alkali metal compound LiF6P. Additionally we examined the effects of gold nanoparticles (AuNPs) alone and with the LiF6P/BGE for possible synergistic effects on electrical conductivity. Thin films of poly (methyl methacrylate) (PMMA) blended with LiF6P salt and AuNPs separately and together, were prepared. The electrical conductivity measurements were carried out on these films as a function of the salt and/or AuNP contents. PMMA with only 0.75 wt.% LiF6P decreased the resistivity by 3 orders of magnitude compared to PMMA, which showed the optimum conductivity value for this system. Formation of BGE–LiF6P complexes were studied by FTIR spectra. XRD studies confirmed the formation of complexes in thin film specimens. It was also found that the conductivity of PMMA with AuNPs is dependent on the size of the AuNPs.