Hydrangea-Inspired Multi-Scale Hybrids: Rational In Situ Assembly of Nickel Phyllosilicates on Polyphosphazene Microspheres to Fabricate Highly Robust, Toughened and Wear-Resistant Epoxy Composites

Epoxy resin (EP) is widely used in machinery and electronics but suffers from marked brittleness and poor wear resistance, which limits its further application under high-speed and heavy-load conditions. To address this issue, hydrangea-inspired multi-scale hybrid particles were rationally designed, with polyphosphazene microspheres (PZM) serving as the substrate and nickel phyllosilicates (NiPS) nanosheets as the decorations. The as-synthesized multi-scale PZM@NiPS hybrids, combining the organic flexibility of PZM and the inorganic rigidity of NiPS, were incorporated into EP matrix at various mass fractions to fabricate a series of composites. Results indicate that the decorated inorganic nanosheets endow PZM@NiPS with a significantly rough surface, contributing to well-bonded interfaces and homogeneous dispersion; these features collectively enhance the mechanical performance of EP/PZM@NiPS composites. When 0.5 wt.% PZM@NiPS is added, the tensile strength, fracture elongation and fracture energy increase by 7.92%, 29.8%, and 180.2%, respectively; however, Shore D hardness increases steadily with PZM@NiPS content. Wet-sliding tests confirm that PZM@NiPS plays a significant positive role in improving wear resistance, and the minimum wear rate of 2.19 × 10 −6 mm 3 /Nm is achieved at a filler content of 1 wt.%, which is a significant reduction of approximately 48.18% compared with pure resin. Finally, the wear mechanism of the EP/PZM@NiPS composites is proposed based on detailed characterization and analysis. This work provides a promising “three-in-one” strategy that enables polymer composites to maintain high hardness while avoiding increased brittleness, thereby offering a novel pathway for the development and application of high-performance polymer-based friction materials suitable for harsh service environments. Highlights PZM@NiPS was rationally synthesized via a biomimetic multi-scale design strategy. Incorporating 0.5 wt.% PZM@NiPS improved the mechanical properties significantly. Adding 1 wt.% PZM@NiPS remarkably suppressed the wear rate by 48.18%. The wear mechanism involving adequate PZM@NiPS was revealed.