Free volume and interstitial mesopores in silica filled poly(I-trimethylsilyl-l-propyne) nanocomposites
The free volume sizes and interstitial mesopore sizes in poly(l-trimethylsilyl-l-propyne) (PTMSP)/silica nanocomposites and the correlation between nitrogen permeability and cavity sizes were studied with positron annihilation lifetime spectroscopy (PALS) at filler concentrations between 0 and 50 wt %. A bimodal free volume distribution was observed for PTMSP, and the size of the larger free volum