Gold-Nanoparticle- and Gold-Nanoshell-Induced Polymorphism in Poly(vinylidene fluoride)

PVDF nanocomposites are prepared through solution mixing of Au-NPs or Au-NSs with PVDF. The novel optical properties of Au-NPs and -NSs are retained as confirmed from UV-Vis spectra. Analysis of resulting nanocomposites by FT-IR, XRD, and DSC shows an obvious polymorphism change from alpha- to beta-form compared to PVDF prepared under the same conditions. The beta-polymorph seems to be more prominent with higher concentration of Au-NPs (0.5%) and even more so with Au-NSs. Thermogravimetric analysis shows that both nanocomposites have better resistance toward thermal degradation. Combination of novel optical properties of Au-NPs or Au-NSs with induced ferroelectric-active beta-polymorph in PVDF can lead to new design of optical, piezoelectric devices.