Polymer Coatings Based on Polyisobutylene, Polystyrene and Poly(styrene-block-isobutylene-block-styrene) for Effective Protection of MXenes

MXene films with a conductivity of about 4000 S/cm were obtained on glass substrates following a drop-casting method and characterized by scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and Raman spectroscopy. The polymer coatings of polystyrene (PSt), polyisobutylene (PIB) and tri-block copolymer of polyisobutylene with styrene (SIBS) were deposited on MXene films and their efficiency toward the protection of MXenes against oxidative degradation was estimated at ambient conditions. A loss of conductivity was detected for PSt-coated MXene films after 220 days of storage, while pristine MXene films stored for 400 days were conductive and their resistivity increased by 2.5 times. Nonpolar polymer coatings based on polyisobutylene and tri-block copolymer of isobutylene with styrene showed ability to protect MXene films from oxidation during a long-term period. After 400 days of storage, the resistivity of the MXene films coated with PIB and SIBS increased by 1.8 and 1.4 times, respectively. The results obtained are of interest for expanding the industrial application of MXene films, increasing their operation by simple coating with nonpolar flexible polymers.