Tuning Polymer Crystallinity in Polymer Nanocomposites

Tuning of the degree of crystallinity can be achieved in poly(ethylene oxide)/silica nanohybrids. Silica nanoparticles of different sizes, i.e., smaller, comparable and larger than the polymer radius of gyration were utilized in order to probe the effect of severe confinement on polymer crystallization. The polymer chains under confinement showed different crystallization characteristics with multiple melting transitions and lower degree of crystallinity. Further, mixtures of silica nanoparticle of two different sizes were introduced to enhance chain confinement. Polymer crystallinity can, indeed, be tuned depending on the ratio of large to small nanoparticles for constant polymer concentration. Even systems with zero crystallinity can be obtained for ternary systems where the fraction of large nanoparticle was kept constant and the ratio of the polymer versus small nanoparticles was varied. Acknowledgements: This research has been co-financed by the General Secretariat for Research and Technology (Action KRIPIS, project AENAO, MIS: 5002556).