Biomimetic Network and Microstructure for Multifunctional Recyclable Ramie Fiber-Reinforced Composites:...

Ramie fiber yarn (PRF), characterized by its superior microwave transmittance (MWT), is a novel material that can effectively substitute traditional glass fiber (D-GF) in the fabrication of composites for communication equipment shells. However, the super hydrophilicity and inadequate thermal conductivity (λ) of PRF hinder its overall performance and safety in use. To date, no effective strategy has been developed to prepare multifunctional PRF-reinforced composites, including high hydrophobicity, MWT, and λ. Herein, by integrating the template method with vacuum-assisted spraying technology, a mosquito-eye-like honeycomb network was constructed on the surface of PRF fabric. This network, composed of nacre-like brick-and-mortar microstructures as its fundamental units, achieves both mesoscopic and microscopic order. The biomimetic network and microstructure enable the PRF fabric to transition from superhydrophilic to high-hydrophobic, significantly reducing water absorption in PRF-reinforced composites to levels similar to D-GF-reinforced composites. Furthermore, the biomimetic structures are incorporated into the composite interface via the fabric surface, resulting in MWT and λ values of up to 98% and 1.0582 W/mK, respectively. Importantly, PRF-reinforced composite waste can be fully transformed to multifunctional particles, thereby enabling closed-loop recycling and reuse. This biomimetic network and microstructure offer an efficient and versatile surface modification strategy for multifunctional composites.