Facile preparation of a polysiloxane-based hybrid composite with highly-oriented boron nitride nanosheets and an unmodified surface

A facile technique was developed to fabricate polysiloxane-based hybrid composite films containing boron nitride (BN) nanosheets using a nanopulse-width electric field. BN nanosheets assumed anisotrophic alignment under the electric field, without requiring surface coating with metallic nano particles despite the wide band gap. BN was dispersed by sonication in a pre-polymer polysiloxane mixture. The homogeneous suspension was cast on a glass spacer and subjected to either a DC electric field or a nanopulse-width electric field before the mixture was cured through polymerization. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that BN nanosheets in the polysiloxane matrix were aligned with high anisotropy to the electric field direction, which was perpendicular to the film plane. The transmittance of the film samples, measured by UV-visible spectrometry, indicated that the composite, prepared using a nanopulse-width electric field manifested a significantly improved transmittance, compared with composites prepared without using the electric field. (c) 2010 Elsevier Ltd. All rights reserved.