A novel nanocomposite dielectric was developed by embedding polyvinylpyrrolidone (PVP)-encapsulated gold (Au) nanoparticles in the polyvinylidene fluoride (PVDF) polymer matrix. The surface functionalization of Au nanoparticles with PVP facilitates favorable interaction between the particle and polymer phase, enhancing nanoparticle dispersion. To study the effect of entropic interactions on particle dispersion, nanocomposites with two different particle sizes (5 and 20 nm in diameter) were synthesized and characterized. A uniform particle distribution was observed for nanocomposite films consisting of 5 nm Au particles, in contrast to the film with 20 nm particles. The frequency-dependent dielectric permittivity and the loss tangent were studied for the nanocomposite films. These results showed the effectiveness of PVP ligand in controlling the agglomeration of Au particles in the PVDF matrix. Moreover, the study showed the effect of particle concentration on their spatial distribution in the polymer matrix and the dielectric properties of nanocomposite films.
Toor A, So H, Pisano AP (2017) Improved Dielectric Properties of Polyvinylidene Fluoride Nanocomposite Embedded with Poly(vinylpyrrolidone)-Coated Gold Nanoparticles. ACS Applied Materials & Interfaces 9: 6369–6375. Available: http://dx.doi.org/10.1021/acsami.6b13900.
This work was supported by King Abdullah University of Science and Technology (KAUST) under award number 25478. The authors gratefully acknowledge support from the Marvell Nanolab facility at University of California, Berkeley, where the capacitor device was fabricated. We would also like to thank the staff of Biomolecular Nanotechnology Center (BNC), where the nanocomposite material was synthesized and characterized.