Surface tailoring of cellulose aerogel-like structures with ultrathin coatings using molecular layer-by-layer assembly

Zhaleh Atoufi; Michael S Reid; Per A Larsson; Lars Wågberg

doi:10.1016/j.carbpol.2022.119098

Surface tailoring of cellulose aerogel-like structures with ultrathin coatings using molecular layer-by-layer assembly

Carbohydr Polym. 2022 Apr 15:282:119098. doi: 10.1016/j.carbpol.2022.119098. Epub 2022 Jan 10.

Authors

Zhaleh Atoufi¹, Michael S Reid², Per A Larsson³, Lars Wågberg⁴

Affiliations

¹ Division of Fibre technology, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden. Electronic address: zhaato@kth.se.
² Division of Fibre technology, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden. Electronic address: mreid@kth.se.
³ Division of Fibre technology, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden. Electronic address: perl5@kth.se.
⁴ Division of Fibre technology, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Fiber and Polymer Technology, Wallenberg Wood Science Center (WWSC), Stockholm, Sweden. Electronic address: wagberg@kth.se.

PMID: 35123738
DOI: 10.1016/j.carbpol.2022.119098

Abstract

Cellulose nanofibril-based aerogels have promising applicability in various fields; however, developing an efficient technique to functionalize and tune their surface properties is challenging. In this study, physically and covalently crosslinked cellulose nanofibril-based aerogel-like structures were prepared and modified by a molecular layer-by-layer (m-LBL) deposition method. Following three m-LBL depositions, an ultrathin polyamide layer was formed throughout the aerogel and its structure and chemical composition was studied in detail. Analysis of model cellulose surfaces showed that the thickness of the deposited layer after three m-LBLs was approximately 1 nm. Although the deposited layer was extremely thin, it led to a 2.6-fold increase in the wet specific modulus, improved the acid-base resistance, and changed the aerogels from hydrophilic to hydrophobic making them suitable materials for oil absorption with the absorption capacity of 16-36 g/g. Thus, demonstrating m-LBL assembly is a powerful technique for tailoring surface properties and functionality of cellulose substrates.

Keywords: Aerogels; Cellulose nanofibril; Molecular layer-by-layer deposition; Oil absorption; Surface functionality; Wet strength.