In Figure 3, typical IR transmission spectra of the
silica-surface modifier trisilanol (IO7) POSS, polymer
polyvinyl chloride (PVC), 30 nm silica/PVC and 130 nm
silica/PVC composites are presented.34 The silanol
groups of open-cage POSS do not spontaneously lead to
condensation, as silanols of other simple alkoxysilanes,
but preferentially interact with the active sites on the
surface of the filler.35 Normally, the bands attributed to
trisilanol POSS are weak because the Si-O-Si bands are
covered by the same band of silica spheres. However, a
closer inspection of the peak intensity of the band at
2907 and 2953 cm–1 indicates a progressive occupation
of the accessible sites on the silica surface. A comparison
of the infrared spectra in the C-H region of
trisilanol POSS (Figure 3 zoom), modified silica/PVC