Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Functionalised graphene sheets as effective high dielectric constant fillers | Romasanta et al. Nanoscale Research Letters 2011 6 508 http content 6 1 508 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Functionalised graphene sheets as effective high dielectric constant fillers Laura J Romasanta Marianella Hernandez Miguel A López-Manchado and Raquel Verdejo Abstract A new functionalised graphene sheet FGS filled poly dimethyl siloxane insulator nanocomposite has been developed with high dielectric constant making it well suited for applications in flexible electronics. The dielectric permittivity increased tenfold at 10 Hz and 2 wt. FGS while preserving low dielectric losses and good mechanical properties. The presence of functional groups on the graphene sheet surface improved the compatibility nanofiller polymer at the interface reducing the polarisation process. This study demonstrates that functionalised graphene sheets are ideal nanofillers for the development of new polymer composites with high dielectric constant values. PACS Keywords dielectric properties graphene interfacial polarisation nanocomposites silicones Introduction In recent years elastomeric materials with high dielectric constant have been considered for different functional applications such as artificial muscles high charge-storage capacitors and high-K gate dielectric for flexible electronics 1 2 . Several methods have been explored in order to increase their dielectric permittivity although the most common approach involves the addition of high dielectric constant ceramics to the elastomeric matrix. This strategy usually requires high loading fractions and hence produces an unwanted increase of the system rigidity for the applications already mentioned 3-5 . In some other cases dielectric constant increments have been met with relatively high loss tangent values tg d and frequency dependence which is also undesirable for capacitor applications 6 7 . Obtaining composites with both high .
