Oriented growth of BaTiO₃ along the basalt fibers and their dielectric properties in poly(ether sulfone)-based composite laminates

To develop high performance of polymer-based composites, the dispersion state and interfacial interaction of nano-fillers are two key issues to be considered. Herein, we report the surface decoration of basalt fibers (BF) with nano-sized barium titanate (BT) particles and their dielectric application in poly(ether sulfone)-based composite laminates (PBCLs) was investigated in detail. Firstly, the nano-sized BT particles uniformly deposited along the BF surface through a simple and effective solvothermal method, as confirmed by SEM and XRD measurement. Then, novel ternary dielectric polymer-based composite laminates, consisting of BT particles decorated BF and poly(ether sulfone) (BT–BF/PES), were fabricated by hot-pressing method. Compared to raw BF filled PBCLs, the SEM images of BT–BF fibers reinforced PBCLs showed that all the BT–BF fibers strongly adhere to the PES matrix, and obscure fiber/PES interfaces are present without visible boundaries, indicating a improved interfacial interactions in this case. Thus, the mechanical, thermal and dielectric properties of the resultant PBCLs were characterized and results indicated that the BF and BT particles show enhanced synergistic effects. Following this strategy, the flexural strength and dielectric constant of BT–BF/PES blend with 40 wt% of BT were increased by 28 and 350%, respectively, in comparison with those of BF/PES composite laminates.