Collagen Nanofiber‐Lignin Composite Sponges with Adjustable Hierarchical Pore Structure for Efficient Low‐Frequency Sound Absorption
Yan Ma, Mu Zha He, Jiaxuan Wang, Fuying Ma, Hongbo Yu, Yaxian Zhou, Shangxian Xie
Abstract
Abstract Current sound‐absorbing materials, reliant on nonrenewable resources, pose sustainability and disposal challenges. This study introduces a novel collagen‐lignin sponge (CLS), a renewable biomass‐based material that combines collagen's acoustic properties with lignin's structural benefits. CLSs demonstrate high porosity (>0.97), lightweight (10 mg cm − 3 ), and exceptional broadband noise absorption performance (sound absorption coefficient exceeding 0.9 across 2000–6300 Hz). Due to their unique hierarchical and aligned pore structure, CLSs display superior low‐frequency sound‐absorbing capabilities and a high noise‐reduction coefficient of 0.64 (for a 30‐mm‐thick sample). A geometric model is also developed to evaluate and predict the sound absorption performance with high consistency to the experimental results. Additionally, the inclusion of lignin as a green crosslinker has significantly improved the thermal stability and compressive strength by ≈600% compared to collagen sponges alone. The innovative integration of collagen and lignin in this study not only leverages the benefits of renewable resources but also presents a cost‐effective and straightforward preparation process, positioning CLS as a promising alternative for the construction of sound‐absorbing materials seeking sustainable solutions.