Structure and properties of carbon intercalated halloysite and its organosilicone hybrid film with low dielectric constant

Due to its hollow structure, halloysite has been considered for owning the potential of application in preparing low dielectric constant material. However its polarity has suppressed such potential and raised the dielectric constant of its polymeric composite. In this study, the non-polar carbon intercalated halloysite (C-HNT) was successfully prepared via in-situ polymerization and thermal treatments. Characterizations of the carbon intercalated halloysite confirmed that acrylonitrile and acrylamide as monomers had been intercalated and copolymerized between the halloysite layers. The copolymer carbonized at 600 degrees C under nitrogen atmosphere with the lumen of halloysite being preserved and water being eliminated. A series of carbon intercalated halloysites/organosilicone hybrid films were prepared via sol-gel process, and their hydrophobicity, thermal property, mechanical property and dielectric property were characterized. The results showed that the present of carbon intercalated halloysite strengthened the hydrophobicity, thermal property, mechanical property of the hybrid film. The lowest dielectric constant of the hybrid film samples was 2.46 at 1 MHz. It reveals that the intercalated process suppresses the polarity of halloysite and revives halloysite's great potential for being used as low dielectric constant material.