Designing Butterfly-Inspired Architecture in Self-Assembled Hybrid Composites for Synergistic Structural Thermal Management.

Increasingly strict environmental regulations and sustainability goals are driving global adoption of lightweight materials in advanced transportation and defense applications. Inspired by nature's unparalleled engineering, this work employs butterfly-hierarchical architectures to develop hybrid composites that emulate the synergy-induced multifunctional performance of natural materials. Specifically, these composites are reinforced with hierarchical fibrous assemblies comprised of nano-sized graphene nanoplatelets (GnPs) covalently bonded onto micro-sized glass fibers (GFs). In detail, this work showcases a novel approach to control the in situ self-assembly behavior of these reinforcements, achieved by tailoring the GFs' surface chemistry through functionalization, to maximize the density of covalently-bonded GnPs. Compared to the current industrial substitute for metallic structural components, the developed hybrid composites are tailorable to achieve improvements up to 29%, 116%, and 109% in specific tensile strength, flexural strength, and impact strength, respectively, as well as 22%, 42%, and 110% in thermal conductivity, thermal management performance, and processability, respectively, with an overall 18% weight-reduction. These advancements stem from the detailed structure-property designs, spanning across multiple length scales, encompassing crystal polymorphism, fiber alignment, and distribution, imparting a fundamental understanding of how to tune material performance to meet stringent requirements. Ultimately, these cost-effective, industry-ready butterfly-inspired hybrid composites can produce lightweight, multifunctional components, demonstrating the potential of hierarchical architecture in advancing sustainable engineering solutions for a greener future.