Percolated interface conductivity of sheet-like electrolyte prepared from poly(2-acrylamido-2-methyl-1-propanesulfonic acid)-deposited core–shell particles and effect of core particle size

Proton conducting poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) ultrathin layer was deposited on sol–gel-derived phenylsilsesquioxane (PhSiO3/2) particles via layer-by-layer (LbL) assembly technique. Spherical and size-controlled particles in the range of 0.3–4.0 μm were successfully prepared by varying the condensation reaction. One PAMPS layer with 1.5 nm thickness was deposited on the particle, the volume fractions of Primer/PAMPS-multilayer varied from 0.7 to 11 vol.%. Sheet-like composite electrolytes in which PAMPS layer percolated throughout the sample can be obtained by hot-pressing the PAMPS-deposited PhSiO3/2 particles. The sample prepared using unmodified PhSiO3/2 exhibited a very low proton conductivity of 10−9 S cm−1 at 80 °C, whereas the conductivity of the composite electrolytes increased significantly with a very small amount of PAMPS-multilayer (∼1 vol.%). The composite with 11 vol.% PAMPS exhibited 2 × 10−3 S cm−1 at 80 °C and 95% of relative humidity.