Confinement Effects on Polymer Morphology and Properties

The behavior of polymers restricted in space or to surfaces/interfaces can be very different from that in the bulk. In this work, we investigate the morphology and thermal properties of poly(ethylene oxide), PEO, in nanohybrids containing two kinds of silica nanoparticles of largely different sizes in an attempt to bridge the case of severely confined polymers within the galleries of layered silicates with that of polymer-single nanoparticle nanocomposites. Hybrids with different ratio between the two silica nanoparticles were prepared in order to increase the level of confinement. The good dispersion of the nanoparticles was verified by transmission electron microscopy whereas the morphology and crystallization behavior were investigated with X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and polarised optical microscopy. The polymer behavior in the three component systems is found indeed intermediate between that of PEO/montmorillonite and that of PEO/silica with a single-size particles. Moreover, the behavior can be tuned by varying the ratio of the large to the small nanoparticles.