Enhanced dielectric performance of polydimethylsiloxane-based ternary composites films via tailored hydrogen bonds between carbon nanotube and barium titanate as modified fillers

A series of BT-cCNT/PDMS and BT-aCNT/PDMS composites were developed by incorporating barium titanate (BT) nanoparticles together with carboxylic functionalized multiwalled carbon nanotubes (cCNT) and amino functionalization multiwalled carbon nanotubes (aCNT) in polydimethylsiloxane (PDMS). Benefitting from the abundant active groups, CNTs and BTs can be in situ "bridged" by hydrogen bond in all of the BT-cCNT/PDMS and BT-aCNT/PDMS composites. Here, we studied the effect of hydrogen bonds (type and amount) between BTs and CNTs at the interface and dielectric properties of the composites. The results indicated that the BT-cCNT/PDMS composite exhibited higher dielectric constant and comparable dielectric loss than the BT-aCNT/PDMS composite, especially when weight(CNT) < 1 wt%. Also, the dielectric properties of BT-cCNT/PDMS composite show stronger temperature dependence than BT-aCNT/PDMS composite. Finally, the tailorable performance of the polymer-based dielectric composites can be obtained by regulating the interface with the help of hydrogen bonds.