The search for more-sustainable materials has motivated research on lightweight, porous structures for thermal insulation and noise reduction, such as for construction and cold-chain transportation. Wood, known as one of the most renewable materials on Earth, has been widely and long used in construction for its high strength/weight ratio, wide abundance, low cost and relative sustainability. However, natural wood is much less effective at reducing noise or preventing heat loss than conventional petroleum- and mineral-based porous structures (for example, expanded polystyrene foam and mineral wool). Here we report the extraordinary noise-reduction and thermal-insulation capabilities of a scalable, high-porosity wood structure, ‘insulwood’, fabricated by removing lignin and hemicelluloses from natural wood using a rapid (~1 h) high-temperature process followed by low-cost ambient drying. Insulwood demonstrates a high porosity of ~0.93, a high noise-reduction coefficient of 0.37 at a frequency range of 250–3,000 Hz (for 10-mm-thick wood), a low radial thermal conductivity of 0.038 W m–1 K–1 and a high compressive strength of ~1.5 MPa at 60% strain. Furthermore, this new wood-based material can be rapidly processed into a vacuum insulation panel (~0.01 W m–1 K–1) for thermal insulation applications with limited space (for example, refrigerators, cold-chain transportation and older buildings). The material is unique in its combination of renewable source materials, high porosity, high sound absorption, low thermal conductivity and high mechanical robustness, as well as in its efficient, cost-effective and scalable manufacturing. These attributes make insulwood promising as a sustainable construction material for improved noise and thermal regulation.
This is a preview of subscription content, access via your institution
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
The data that support the findings of this study are available within this article and its Supplementary Information. Source data are provided with this paper.
2020 Global Status Report for Buildings and Construction: Towards a Zero-Emission, Efficient and Resilient Buildings and Construction Sector (UNEP, 2020).
Cao, L., Fu, Q., Si, Y., Ding, B. & Yu, J. Porous materials for sound absorption. Compos. Commun. 10, 25–35 (2018).
Apostolopoulou‐Kalkavoura, V., Munier, P. & Bergström, L. Thermally insulating nanocellulose‐based materials. Adv. Mater. 33, 2001839 (2021).
Zhao, X., Brozena, A. H. & Hu, L. Critical roles of pores and moisture in sustainable nanocellulose-based super-thermal insulators. Matter 4, 769–772 (2021).
Liu, H. & Zhao, X. Thermal conductivity analysis of high porosity structures with open and closed pores. Int. J. Heat Mass Transf. 183, 122089 (2022).
Lavoine, N. & Bergström, L. Nanocellulose-based foams and aerogels: processing, properties, and applications. J. Mater. Chem. A 5, 16105–16117 (2017).
Asdrubali, F., D’Alessandro, F. & Schiavoni, S. A review of unconventional sustainable building insulation materials. Sustain. Mater. Technol. 4, 1–17 (2015).
Schiavoni, S., Bianchi, F. & Asdrubali, F. Insulation materials for the building sector: a review and comparative analysis. Renew. Sustain. Energy Rev. 62, 988–1011 (2016).
Forouharmajd, F. & Mohammadi, Z. Assessment of normal incidence absorption performance of sound absorbing materials. Int. J. Environ. Health Eng. 5, 10 (2016).
Yang, T. et al. Sound absorption properties of natural fibers: a review. Sustainability 12, 8477 (2020).
Liu, L. et al. The development history and prospects of biomass-based insulation materials for buildings. Renew. Sustain. Energy Rev. 69, 912–932 (2017).
Hill, C., Norton, A. & Dibdiakova, J. A comparison of the environmental impacts of different categories of insulation materials. Energy Build. 162, 12–20 (2018).
Papadopoulos, A. M. & Giama, E. Environmental performance evaluation of thermal insulation materials and its impact on the building. Build. Environ. 42, 2178–2187 (2007).
Xia, Q. et al. A strong, biodegradable and recyclable lignocellulosic bioplastic. Nat. Sustain. 4, 627–635 (2021).
Esau, R., Jungclaus, M., Olgyay, V. & Rempher, A. Reducing Embodied Carbon in Buildings (RMI, 2021).
Chen, C. et al. Structure–property–function relationships of natural and engineered wood. Nat. Rev. Mater. 5, 642–666 (2020).
Koshijima, T. & Watanabe, T. Association Between Lignin and Carbohydrates in Wood and Other Plant Tissues (Springer, 2013).
Suleiman, B., Larfeldt, J., Leckner, B. & Gustavsson, M. Thermal conductivity and diffusivity of wood. Wood Sci. Technol. 33, 465–473 (1999).
Lin, M.-D., Tsai, K.-T. & Su, B.-S. Estimating the sound absorption coefficients of perforated wooden panels by using artificial neural networks. Appl. Acoust. 70, 31–40 (2009).
Asdrubali, F. et al. A review of structural, thermo-physical, acoustical, and environmental properties of wooden materials for building applications. Build. Environ. 114, 307–332 (2017).
Kang, C., Kang, W., Chung, W., Matsumura, J. & Oda, K. Changes in anatomical features, air permeability and sound absorption capability of wood induced by delignification treatment. 53, 479–483 (Faculty of Agriculture, Kyushu University, 2008).
Kolya, H. & Kang, C. W. High acoustic absorption properties of hackberry compared to nine different hardwood species: a novel finding for acoustical engineers. Appl. Acoust. 169, 107475 (2020).
Li, J., Chen, C., Zhu, J., Ragauskas, A. J. & Hu, L. In situ wood delignification toward sustainable applications. Acc. Mater. Res. 2, 606–620 (2021).
Guan, H., Cheng, Z. & Wang, X. Highly compressible wood sponges with a spring-like lamellar structure as effective and reusable oil absorbents. ACS Nano 12, 10365–10373 (2018).
Song, J. et al. Highly compressible, anisotropic aerogel with aligned cellulose nanofibers. ACS Nano 12, 140–147 (2018).
Li, T. et al. Anisotropic, lightweight, strong, and super thermally insulating nanowood with naturally aligned nanocellulose. Sci. Adv. 4, eaar3724 (2018).
Zhu, M. et al. Highly anisotropic, highly transparent wood composites. Adv. Mater. 28, 5181–5187 (2016).
Wang, J. et al, Carbonate pre-treatment of wood for transformative structural applications through densification. Ind Crops Prod. 183, 188 (2022).
Sun, J. et al. Enhanced mechanical energy conversion with selectively decayed wood. Sci. Adv. 7, eabd9138 (2021).
Pour, G., Beauger, C., Rigacci, A. & Budtova, T. Xerocellulose: lightweight, porous and hydrophobic cellulose prepared via ambient drying. J. Mater. Sci. 50, 4526–4535 (2015).
Xiao, S. et al. Lightweight, strong, moldable wood via cell wall engineering as a sustainable structural material. Science 374, 465–471 (2021).
Ek, M., Gellerstedt, G. & Henriksson, G. Pulping Chemistry and Technology Vol. 2 (Walter de Gruyter, 2009).
Kamali, M. & Khodaparast, Z. Review on recent developments on pulp and paper mill wastewater treatment. Ecotoxicol. Environ. Saf. 114, 326–342 (2015).
López, F., Pérez, A., Zamudio, M. A., De Alva, H. E. & García, J. C. Paulownia as raw material for solid biofuel and cellulose pulp. Biomass Bioenergy 45, 77–86 (2012).
Yadav, N. K. et al. A review of paulownia biotechnology: a short rotation, fast growing multipurpose bioenergy tree. Am. J. Plant Sci. 4, 2070 (2013).
Borrega, M., Tolonen, L. K., Bardot, F., Testova, L. & Sixta, H. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping. Bioresour. Technol. 135, 665–671 (2013).
Pettersen, R. C. in The Chemistry of Solid Wood (ed. Rowell, R.) 57–126 (ACS, 1984).
Kellogg, R. M. & Wangaard, F. F. Variation in the cell-wall density of wood. Wood Fiber Sci. 1, 180–204 (1969).
Ross, R. J. Wood Handbook: Wood as an Engineering Material General Technical Report FPL-GTR-190 (USDA, 2010).
Acoustics—Determination of Sound Absorption Coefficient and Impedance in Impedance Tubes—Part 2: Transfer-Function Method (ISO, 1998).
Sikora, J. & Turkiewicz, J. Sound absorption coefficients of granular materials. Mech. Control 29, 149–157 (2010).
Putra, A., Abdullah, Y., Efendy, H., Mohamad, W. & Salleh, N. Biomass from paddy waste fibers as sustainable acoustic material. Adv. Acoust. Vib. 2013, 605932 (2013).
Shen, L. et al. Hierarchical pore structure based on cellulose nanofiber/melamine composite foam with enhanced sound absorption performance. Carbohydr. Polym. 255, 117405 (2021).
Jia, C. et al. Highly compressible and anisotropic lamellar ceramic sponges with superior thermal insulation and acoustic absorption performances. Nat. Commun. 11, 3732 (2020).
Jelle, B. P. Traditional, state-of-the-art and future thermal building insulation materials and solutions—properties, requirements and possibilities. Energy Build. 43, 2549–2563 (2011).
Eitelberger, J. & Hofstetter, K. Prediction of transport properties of wood below the fiber saturation point—a multiscale homogenization approach and its experimental validation: part I: thermal conductivity. Compos. Sci. Technol. 71, 134–144 (2011).
Zhao, X. et al. Reduced-scale hot box method for thermal characterization of window insulation materials. Appl. Therm. Eng. 160, 114026 (2019).
Beluns, S. et al. From wood and hemp biomass wastes to sustainable nanocellulose foams. Ind. Crops Prod. 170, 113780 (2021).
Chapelle, L. Characterization and Modelling of the Mechanical Properties of Mineral Wool. PhD thesis, Technical University of Denmark (2016).
Kalnæs, S. E. & Jelle, B. P. Vacuum insulation panel products: a state-of-the-art review and future research pathways. Appl. Energy 116, 355–375 (2014).
Sluiter, A. et al. Determination of Structural Carbohydrates and Lignin in Biomass Technical Report NREL/TP-510-42618 (NREL, 2008).
Standard Test Method for Impedance and Absorption of Acoustical Materials Using a Tube, Two Microphones and a Digital Frequency Analysis System ASTM E1050-19 (ASTM, 2019).
L.H., X.Z., A.G., J.D., D.S. and J.Y.Z. acknowledge the support from the Department of Energy’s Building Technologies Office (BTO) through the Small Business Innovation Research Program under Contract DE-SC0018820. L.H., X.Z., A.P.S., A.G., J.D., J.K. and J.Y.Z. acknowledge the support from the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Building Technologies Office (BTO), Award Number DE-EE0009702. X.Z. also acknowledges the use and support of the Maryland NanoCenter and its AIMLab.
The authors declare the following competing interests: Dr. Liangbing Hu co-founded a company, InventWood, to commercialize wood-based thermal/acoustic insulation materials. However, all results reported herein were performed under federal sponsorship. The remaining authors declare no competing interests.
Peer review information
Nature Sustainability thanks Kai Zhang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Disclaimer The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology.
FTIR spectra of the natural wood and insulwood.
The sound-absorption coefficient of the natural wood and insulwood as a function of frequency.
Stress–strain curves of the insulwood under compression along the radial direction.
Comparison of the outgassing rate of the insulwood and EPS.
About this article
Cite this article
Zhao, X., Liu, Y., Zhao, L. et al. A scalable high-porosity wood for sound absorption and thermal insulation. Nat Sustain 6, 306–315 (2023). https://doi.org/10.1038/s41893-022-01035-y
This article is cited by
Scientific Reports (2023)