Poly(dimethyl siloxane)-based copolymer dielectric composites with copper sulfide loaded carbon nanotubes doped with carbon quantum dots

Herein we used copper sulfide loaded carbon nanotubes and poly(dimethyl siloxane)-based copolymers to prepare composite films, while doping the filler with carbon quantum dots to strengthen the dielectric constant and curb the dielectric loss. The composite prepared with a filler content of 2.33 vol% has a dielectric constant of 53.34 and a dielectric loss of 0.05 at 100 Hz and room temperature. [Display omitted] •Fillers with excellent dispersion in the organic phase was prepared.•The PDMS-based composites exhibited excellent dielectric properties at 100 Hz.•The mechanism of the enhancement of dielectric properties is explained in depth. The renewal of electromechanical transducers is tightly linked to the ongoing development of elastomers with excellent dielectric properties, but this positive progress is often plagued by the dilemma of the lower dielectric constant of the elastomers themselves. In this work, carbon nanotubes loaded with copper sulfide and doped with carbon quantum dots (abbreviated as CD-CuS@CNT) were successfully fabricated through hydrothermal reaction, followed by the incorporation of this filler into poly(dimethyl siloxane)-based copolymers (H-PDMS for short) to form percolation composites, additionally co-blended composite films of H-PDMS and carbon nanotubes loaded with copper sulfide were prepared as a control. Results exhibit that the permittivity of 2.33 vol% CD-CuS@CNT/H-PDMS composites is 53.34 at 100 Hz, which is 1.3 and 19.2 times that of 2.12 vol% CuS@CNT/H-PDMS and pure H-PDMS, while the loss is only 0.05. Moreover, the investigation revealed the role of carbon quantum dots in the whole system to enhance the dielectric properties of the composites.