Mapping absorbency in cellulosic fibres with iron tracers

Elisa S Ferreira; James Drummond; Anderson T V Veiga; Aurélien Sibellas; Samuel Brown; Emily D Cranston; D Mark Martinez

doi:10.1016/j.carbpol.2023.120785

Mapping absorbency in cellulosic fibres with iron tracers

Carbohydr Polym. 2023 Jul 1:311:120785. doi: 10.1016/j.carbpol.2023.120785. Epub 2023 Mar 8.

Authors

Elisa S Ferreira¹, James Drummond², Anderson T V Veiga³, Aurélien Sibellas², Samuel Brown², Emily D Cranston⁴, D Mark Martinez²

Affiliations

¹ Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil; Bioproducts Institute, University of British Columbia, Vancouver, BC, Canada. Electronic address: elisa.ferreira@lnnano.cnpem.br.
² Bioproducts Institute, University of British Columbia, Vancouver, BC, Canada; Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, Canada.
³ Department of Wood Science, University of British Columbia, Vancouver, BC, Canada; Bioproducts Institute, University of British Columbia, Vancouver, BC, Canada.
⁴ Department of Wood Science, University of British Columbia, Vancouver, BC, Canada; Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, Canada.

PMID: 37028851
DOI: 10.1016/j.carbpol.2023.120785

Abstract

Understanding water absorbency in paper is challenging as fibre swelling and out-of-plane deformation occur simultaneously during liquid imbibition. Liquid absorption is commonly accessed by gravimetric tests, which provides limited information on the local spatial and temporal distribution of fluid in the substrate. In this work, we developed iron tracers to map liquid imbibition in paper by in situ precipitation of iron oxide nanoparticles during passage of the wetting front. The iron oxide tracers were found to be robustly attached to the cellulosic fibres. After liquid absorption tests, absorbency was investigated by mapping the distribution of iron in 3D using X-ray micro-computed tomography (μCT) and in 2D using energy-dispersive X-ray spectroscopy. We demonstrate a difference in tracer distribution between the wetting front and the fully saturated region supporting that imbibition proceeds in two phases, i.e. liquid percolation through the cell wall initially prior to filling of the external pore spaces. Critically, we demonstrate that these iron tracers enhance image contrast and allow for new imaging modalities in μCT for fibre networks.

Keywords: Cellulose (CID: 14055602); Energy-dispersive X-ray analysis; Iron (II) sulphate (CID: 62662); Iron (II, III) oxide (CID: 16211978); Iron oxide; Nanoparticles; Paper; Wetting; X-ray micro-computed microtomography.