University of Oulu

Panpan Li, Juho Antti Sirviö, Shu Hong, Ari Ämmälä, Henrikki Liimatainen, Preparation of flame-retardant lignin-containing wood nanofibers using a high-consistency mechano-chemical pretreatment, Chemical Engineering Journal, Volume 375, 2019, 122050, ISSN 1385-8947,

Preparation of flame-retardant lignin-containing wood nanofibers using a high-consistency mechano-chemical pretreatment

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Author: Li, Panpan1; Sirviö, Juho Antti1; Hong, Shu2;
Organizations: 1Fibre and Particle Engineering Research Unit, University of Oulu, P. O. Box 4300, FI-90014 Oulu, Finland
2College of Materials Science and Technology, Nanjing Forestry University, Nanjing 210037, China
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 2.2 MB)
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Language: English
Published: Elsevier, 2019
Publish Date: 2021-06-22


Deep eutectic solvents (DESs) can be used as green media for lignocellulosic nanofiber production. However, typically, a high liquid-to-lignocellulose ratio is required (i.e. the consistencies of biomass are low, usually limited from 1 to 5 wt%), which greatly reduces the sustainability of DES use. In the present work, wood sawdust was first anionized using a reactive DES (formed from sulfamic acid and urea) at a high mass consistency (with gradually increased sawdust consistencies up to 60 wt%) in the pre-milling and post-heating processes. Anionic sawdust nanofibers (ASNFs) were then produced after mild nanofibrillation (two passes) using a microfluidizer. The processes of producing ASNFs were fast (1 h of pretreatment) and the ASNFs was obtained with high sulfate group contents (up to 3.1 mmol g−1). Besides, the ASNFs possessed a well-individualized structure with a homogeneous size distribution (3–5 nm in width). More importantly, films fabricated from ASNFs achieved strong flame resistance and good mechanical strength. Due to the presence of lignin, ASNF films were able to block over 90% of UV light (at a wavelength of 200–400 nm). The investigated functionalities of ASNFs led the lignocellulosic biomass residuals to be converted to high value-added bioproducts. Therefore, the reactive DES treatment combined with milling and heating process offers a practical and sustainable route for multi-functional biomaterial production, which can be potentially utilized, even at an industrial scale.

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Series: Chemical engineering journal
ISSN: 1385-8947
ISSN-E: 1873-3212
ISSN-L: 1385-8947
Volume: 375
Article number: 122050
DOI: 10.1016/j.cej.2019.122050
Type of Publication: A1 Journal article – refereed
Field of Science: 215 Chemical engineering
221 Nanotechnology
216 Materials engineering
Copyright information: © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license