Enhanced dielectric and hydrophobic properties of PDMS/P(VDF-TrFE) blend films by embedding PS microspheres

This paper reports a feasible method to prepare pure organic polymeric nanocomposites with enhanced dielectric and hydrophobic performance. Homogeneous polystyrene (PS) microspheres with an average diameter of about 250 nm was firstly synthesized through emulsion polymerization. The blend film containing PS, PDMS and P(VDF-TrFE) are prepared by a simple solution-blending and spin-coating method. The blend film exhibits enhanced dielectric and hydrophobic properties. Typically, the dielectric constant of the blend film with 23 wt% PS reaches 21 at 100 Hz, which is 3 times that of PDMS/P(VDF-TrFE) (mass ratio: 2/3) due to enhanced interfacial polarization caused by PS addition. Meanwhile, the blend film with 23 wt% PS possesses a large apparent contact angle of 125° because the presence of a rough surface makes the solid-liquid contact surface larger than the apparently observed area, thus enhancing hydrophobicity. All the improved performances show great potential application for electrowetting devices.