Influence of TiO2 nanoparticles on formation mechanism of PANI/TiO2 nanocomposite coating on PET fabric and its structural and electrical properties

Abstract

Polyester fibers gained significant share from all other man-made fibers, but despite numerous advantages a characteristic static electricity generation is still seeking innovative solutions. In order to improve electrical properties of poly(ethyleneterephthalate) (PET) fabric, coating consisting of polyaniline/TiO2 (PANI/TiO2) nanocomposite was deposited on its surface. Coating was synthesized in acidic medium by the chemical oxidative polymerization of aniline with ammonium peroxydisulfate CAPS) in the presence of colloidal TiO2 nanoparticles (d similar to 4.5 nm) and PET fabric. The morphology, molecular structure and dielectric properties of PANI/TiO2 nanocomposites were studied by scanning electron microscopy (SEM), Raman and dielectric spectroscopies. SEM analysis revealed the formation of non-uniform PANI coating on the reference PET sample. In contrast, uniform PANI/TiO2 coating on the surface of PET fabric was generated when TiO2 nanoparticles were engaged. The existence of conductive emeraldine salt form of PANI and phenazine units was confirmed by Raman spectroscopy. Formation mechanisms of PANI and PANI/TiO2 coatings on PET fabrics were proposed. The presence of TiO2 nanoparticles significantly affected the dielectric properties (permittivity and loss tangent) and AC conductivity of PANI/TiO2 coated PET fabrics. PET fabrics coated by PANI/TiO2 nanocomposite showed up to two orders of magnitude higher conductivity in the measured frequency region compared to PANI coated PET fabric.