University of Oulu

Berglund, L., Nissilä, T., Sivaraman, D., Komulainen, S., Telkki, V.-V., & Oksman, K. (2021). Seaweed-Derived Alginate–Cellulose Nanofiber Aerogel for Insulation Applications. ACS Applied Materials & Interfaces, 13(29), 34899–34909.

Seaweed-derived alginate–cellulose nanofiber aerogel for insulation applications

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Author: Berglund, Linn1; Nissilä, Tuukka2; Sivaraman, Deeptanshu3;
Organizations: 1Division of Materials Science, Luleå University of Technology, SE 971 87 Luleå, Sweden
2Fiber and Particle Engineering Research Unit, University of Oulu, FI 90570 Oulu, Finland
3Empa—Building Energy Materials and Components, Swiss Federal Laboratories for Materials Science and Technology, CH 8600 Dübendorf, Switzerland
4NMR Research Unit, University of Oulu, FI 90570 Oulu, Finland
5Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 5.3 MB)
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Language: English
Published: American Chemical Society, 2021
Publish Date: 2021-08-17


The next generation of green insulation materials is being developed to provide safer and more sustainable alternatives to conventional materials. Bio-based cellulose nanofiber (CNF) aerogels offer excellent thermal insulation properties; however, their high flammability restricts their application. In this study, the design concept for the development of a multifunctional and non-toxic insulation material is inspired by the natural composition of seaweed, comprising both alginate and cellulose. The approach includes three steps: first, CNFs were separated from alginate-rich seaweed to obtain a resource-efficient, fully bio-based, and inherently flame-retardant material; second, ice-templating, followed by freeze-drying, was employed to form an anisotropic aerogel for effective insulation; and finally, a simple crosslinking approach was applied to improve the flame-retardant behavior and stability. At a density of 0.015 g cm⁻³, the lightweight anisotropic aerogels displayed favorable mechanical properties, including a compressive modulus of 370 kPa, high thermal stability, low thermal conductivity (31.5 mW m⁻¹ K⁻¹), considerable flame retardancy (0.053 mm s⁻¹), and self-extinguishing behavior, where the inherent characteristics were considerably improved by crosslinking. Different concentrations of the crosslinker altered the mechanical properties, while the anisotropic structure influenced the mechanical properties, combustion velocity, and to some extent thermal conductivity. Seaweed-derived aerogels possess intrinsic characteristics that could serve as a template for the future development of sustainable high-performance insulation materials.

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Series: ACS applied materials & interfaces
ISSN: 1944-8244
ISSN-E: 1944-8252
ISSN-L: 1944-8244
Volume: 13
Issue: 29
Pages: 34899 - 34909
DOI: 10.1021/acsami.1c07954
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
116 Chemical sciences
216 Materials engineering
Funding: The authors are grateful for the financial support of the European Regional Development Fund under the Interreg Nord within the Sea-Surf-Snow project [20201287] and the Swedish strategic research program Bio4Energy, KAW [2018.0451], WWSC and Kempe Foundations for the use of X-ray microtomography. D.S. would like to acknowledge funding from the Swiss National Science Foundation of the project [200021_179000]. V.-V.T. acknowledges the financial support from the European Research Council (ERC) under Horizon 2020 (H2020/2018-2022/ERC grant agreement no. 772110).
EU Grant Number: (772110) UFLNMR - Ultrafast Laplace NMR
Copyright information: © 2021 The Authors. Published by American Chemical Society. CC BY.