Multifunctional cellulose wood with effective acoustic absorption

Wood is a sustainable material with big sound absorption potential based on its natural porous characteristics. However, the acoustic absorption performance of wood is greatly limited by the low permeability of wood structures. In this study, we prepared a new type of cellulose wood (CW) using a two-step delignification process on a natural basswood matrix followed by supercritical CO2 drying. The as-prepared CW exhibited a high air permeability of 33.78 Darcys (increase of 496.82%) and superior porous characteristics compared to the natural basswood, resulting in a significant improvement in the acoustic absorption performance with an increased average absorption of 106.25% and maximum absorption of 126.32%. The dissipation of sound energy in the structure of CW is well predicted by a designed porous media model. Moreover, a high specific stiffness of 2.14 x 10(5) m(2) s(-2) and a diffuse reflectance of 97.02% across the visible light were demonstrated for the CW as well. Such a fascinating multifunctional wood-derived material may provide new insights into the development of efficient and sustainable acoustic absorbers for various applications. (c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

Wood is a sustainable material that has potential for sound absorption due to its porous characteristics. However, the low permeability of wood structures limits its acoustic absorption performance. In this study, a new type of cellulose wood (CW) was prepared through a two-step delignification process and supercritical CO2 drying. The CW exhibited high air permeability and superior porous characteristics compared to natural basswood, resulting in significant improvement in acoustic absorption performance. The CW also demonstrated high specific stiffness and diffuse reflectance across visible light.