A novel high permittivity percolative composite with modified MXene

A high permittivity acrylic resin (AE)-based percolative composite with two-dimensional (2D) MXene nanosheets as the conducting fillers was fabricated. The Ti 3 C 2 T x MXene nanosheets were delaminated (referred to d-Ti 3 C 2 T x ) and then modified with polypyrrole (PPy). The d-Ti 3 C 2 T x /AE and PPy- d -Ti 3 C 2 T x /AE composite films with different filler loadings were obtained with the solution casting method. The dielectric constants of 6.36 vol %d-Ti 3 C 2 T x /AE and 5.98 vol %PPy- d -Ti 3 C 2 T x /AE are 493 and 265 at 10 2  Hz, respectively, approximately 140 and 75 times of pure AE (3.5). Meanwhile, the dielectric loss of PPy- d -Ti 3 C 2 T x /AE composite maintains at a relative low level (0.23 at 10 3  Hz) when the volume fraction of PPy- d -Ti 3 C 2 T x gets close to the percolation threshold ( f c  = 6.39). The large enhancement in dielectric constant of composite is closely relevant to the microcapacitor effect and the free charge accumulation caused by the formation of interfaces between the conducting fillers and polymer matrix .