Abstract
Hypothesis: Underwater oil-repellency of polyelectrolyte brushes has been attributed mainly to electric double-layer repulsion forces based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Many non-polyelectrolyte materials also exhibit oil-repellent behaviour, but it is not clear if there exist similar electric double-layer repulsion and if it is the sole mechanism governing their underwater oil-repellency. Experiments/simulations: In this article, the oil-repellency of highly amorphous cellulose exhibiting is investigated in detail, through experiments and molecular dynamics simulations (MDS). Findings: It was found that the stable surface hydration on regenerated cellulose was due to a combination of long-range electrostatic repulsions (DLVO theory) and short-range interfacial hydrogen bonding between cellulose and water molecules (as revealed by MDS). The presence of a stable water layer of about 200 nm thick (similar to that of polyelectrolyte brushes) was confirmed. Such stable surface hydration effectively separates cellulose surface from oil droplets, resulting in extremely low adhesion between them. As a demonstration of its practicality, regenerated cellulose membranes were fabricated via electrospinning, and they exhibit high oil/water separation efficiencies (including oil-in-water emulsions) as well as self-cleaning ability.
Original language | English (US) |
---|---|
Pages (from-to) | 197-207 |
Number of pages | 11 |
Journal | Journal of colloid and interface science |
Volume | 635 |
DOIs | |
State | Published - Apr 2023 |
Bibliographical note
Funding Information:This work was partially supported by A*STAR IMRE - SCG Chemicals Advanced Composite Joint Lab (IAF-ICP Project No: I1801E0024).
Publisher Copyright:
© 2022 Elsevier Inc.
Keywords
- Membrane
- Oil/water separation
- Regenerated cellulose
- Surface hydration
- Underwater oil-repellency
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry