Nanocomposite films dispersed with silica nanoparticles extracted from earthworm humus

Research in the field of polymer electrolytes in recent years has been focused in achieving maximum conductivity at ambient conditions. Addition of ceramic nanoparticles to polymer matrices has been found to be an effective way to realize large ionic conductivity. A cost effective method of extracting silica nanoparticles from earthworm humus has been reported. To prepare polymer electrolyte films of PVA-PVP blend in 50:50 ratio by weight was taken as the polymer matrix and orthophosphoric acid (H3PO4) was added to the polymer blend solution. Nanocomposite polymer electrolytes were prepared by adding known amounts of SiO2 nanoparticles to polymer electrolyte solution. XRD scans of the polymer electrolyte films reveal a well dispersed state of the nanoparticles in the polymer matrix. DSC studies have shown a reduction in Tg of the polymer electrolytes with addition of SiO2 nanoparticles. The highest conductivity has been found to be 2.4 x 0(-4) S/cm at 2 wt.% silica doping at room temperature. Transference number measurements have shown that the conductivity of the samples is mainly dominated by the motion of the ions. (C) 2012 Elsevier B.V. All rights reserved.