Zinc Oxide Nanowire-Enhanced Interlocking Interfaces in Mechanically Robust Basalt Fiber/Epoxy Lamellar Composites

Abstract

The contradiction between the widespread application of basalt fibers (BFs) and their poor interfacial interaction with polymers has become an urgent issue for the preparation of BF/thermosetting polymer composites. In this study, zinc oxide (ZnO) nanofibers were successfully grown on the surface of BFs through a surface modification process involving polydopamine (PDA) coating, followed by a two-step hydrothermal method to create an interfacial interlocking structure. As a result, the interfacial interaction between the modified BFs and epoxy resin was significantly enhanced, as evidenced by the increase in interfacial shear strength from 13.3 to 22.4 MPa, greatly improving the mechanical properties of the resulting composite. The impact toughness and flexural strength of the modified composites increased from 46.4 kJ/m² and 278.4 MPa to 59.6 kJ/m² and 347.5 MPa, respectively. This not only addresses the issue of weak interfacial interaction between BFs and polymers to expand the application potential of BFs, but also provides an effective strategy for the other inorganic fibers to enhance the interfacial interaction with polymer.