Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams

Melissa B Agustin; Neda Nematollahi; Mamata Bhattarai; Erfan Oliaei; Mari Lehtonen; Orlando J Rojas; Kirsi S Mikkonen

doi:10.1007/s10570-023-05399-y

Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams

Cellulose (Lond). 2023;30(14):8955-8971. doi: 10.1007/s10570-023-05399-y. Epub 2023 Jul 29.

Authors

Melissa B Agustin^{1

2}, Neda Nematollahi¹, Mamata Bhattarai^{1

3}, Erfan Oliaei⁴, Mari Lehtonen¹, Orlando J Rojas^{3

5}, Kirsi S Mikkonen^{1

6}

Affiliations

¹ Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
² Present Address: VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 Espoo, Finland.
³ Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076 Aalto, Finland.
⁴ Wallenberg Wood Science Center, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
⁵ Bioproducts Institute, Department of Chemical and Biological Engineering, Department of Chemistry and Department of Wood Science, University of British Columbia, 2360, East Mall, Vancouver, BC V6T 1Z3 Canada.
⁶ Helsinki Institute of Sustainability Science, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland.

Abstract

Nanocellulose is very hydrophilic, preventing interactions with the oil phase in Pickering emulsions. This limitation is herein addressed by incorporating lignin nanoparticles (LNPs) as co-stabilizers of nanocellulose-based Pickering emulsions. LNP addition decreases the oil droplet size and slows creaming at pH 5 and 8 and with increasing LNP content. Emulsification at pH 3 and LNP cationization lead to droplet flocculation and rapid creaming. LNP application for emulsification, prior or simultaneously with nanocellulose, favors stability given the improved interactions with the oil phase. The Pickering emulsions can be freeze-dried, enabling the recovery of a solid macroporous foam that can act as adsorbent for pharmaceutical pollutants. Overall, the properties of nanocellulose-based Pickering emulsions and foams can be tailored by LNP addition. This strategy offers a unique, green approach to stabilize biphasic systems using bio-based nanomaterials without tedious and costly modification procedures.

Supplementary information: The online version contains supplementary material available at 10.1007/s10570-023-05399-y.

Keywords: Adsorption; Foams; Lignin nanoparticles; Nanocellulose; Pharmaceutical pollutants; Pickering emulsions.