Hybrid Amyloid–Boron Nitride Aerogels for Lightweight Sound Insulation

Abstract

ABSTRACT Boron nitride (BN) is a lightweight, thermally stable, and chemically inert material widely used in electronics and insulation, yet its synthesis typically relies on energy‐intensive, high‐temperature routes. Here, we introduce a sustainable, bottom‐up strategy to fabricate hybrid boron nitride–amyloid fibril (BNAF) aerogels, in which whey protein amyloid fibrils serve as renewable scaffolds that assist the organization of BN‐rich domains. A mild ultrasonication–freeze‐drying process yields ultralight aerogels with hierarchical porosity, increased BN‐like ordering relative to the protein‐free control, and fibril‐induced reinforcement. The hybrid aerogels combine mechanical reinforcement, thermal stability under moderate‐use conditions, and strong acoustic performance, achieving sound absorption coefficients above 0.8, noise reduction coefficients up to 0.63, and sound transmission losses of 25–30 dB. This combination of low density and strong sound shielding compares favorably with common lightweight acoustic materials such as fiberglass, establishing amyloid‐assisted BN–protein hybrid aerogels as promising candidates for moderate‐temperature, weight‐sensitive noise‐reduction applications.