Penetration based CNT/Sol-Gel composite films and their remarkable electrical properties

In this work we present a novel method for CNT/Sol-Gel film preparation, combining low resistivity and improved adhesion behaviour on glass substrates. Naturally occurring voids, with diameters of 50-100 nm, in sprayed CNT networks are used for Sol-Gel penetration via dip coating method. Thermal treatments, for composite film densification, in the range of 200-700°C are investigated and electrical properties were compared to identically treated reference samples with the same batch of nanotubes but without Sol-Gel. The resistivity of such composite films, with best value of 0.03 cm for MWNTs, is two orders of magnitudes lower than previously reported for CNT/Sol-Gel composites. Surprisingly the surface resistance of the composite film shows 25% improvement compared to thermally equal treated pure CNT films. In addition, crosscut adhesion behaviour is investigated, including tape test, showing good performance for composite films, where Sol-Gel acts as an adhesion promoter.