Metilli, L, Storm, M, Bodey, AJ et al. (5 more authors) (2021) Investigating the microstructure of soft, microporous matter with synchrotron X-ray tomography. Materials Characterization, 180. 111408. ISSN 1044-5803
Abstract
Soft porous matter is commonly encountered in artificial tissue applications, pharmaceuticals delivery systems and in cosmetic and food products. These materials are typically opaque and tend to deform under very small levels of shear; this makes the characterization of their microstructure very challenging, particularly in the native state. Air-in-oil systems (oleofoams) are an emerging type of soft material with promising applications in cosmetics and foods, which contain air bubbles stabilized by Pickering fat crystals dispersed in a liquid oil phase. Synchrotron radiation X-ray computed tomography (SR - XCT) is a non-invasive, non-destructive technique increasingly used to investigate multiphasic, porous materials, owing to its high flux which enables sub-micron resolution and significant statistics at rapid acquisition speed. While the penetration of high energy X-rays can provide high resolution images and allows the reconstruction of the 3D structure of samples, the experimental setup and measuring parameters need to be carefully designed to avoid sample deformation or beam damage.
In this work, a robust methodology for investigating the 3D microstructure of soft, porous matter was developed. Sample preparation and experimental setup were chosen to allow synchrotron tomographic analysis of soft oleofoams with a low melting point (<30 °C). In particular, the use of cryogenic conditions (plunge-freeze in liquid nitrogen) provided stability against melting during the acquisition. Additionally, an image processing workflow was designed for analysing the 3D microstructure of the samples using ImageJ. Hence, the size and shape distribution of the air phase, as well as the thickness of the continuous gel phase could be determined for samples with significantly different microstructures (fresh vs. heated). Furthermore, the use of time-resolved X-ray radiography (XRR) allowed to study dynamic changes in the microstructure of the samples during thermal destabilization, visualizing bubble coalescence and growth in optically opaque foam samples with a sub-second timescale.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2021 Elsevier Inc. All rights reserved. This is an author produced version of an article published in Materials Characterization. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | X-ray tomography; Oleofoams; Image analysis; Bubble; Soft porous matter |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Sep 2021 09:16 |
Last Modified: | 27 Aug 2022 00:13 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.matchar.2021.111408 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:178335 |
Downloads
Filename: Methodology_paper_manuscript_submission.pdf
Licence: CC-BY-NC-ND 4.0
Filename: Methodology_paper_SI_submission.pdf
Licence: CC-BY-NC-ND 4.0