TY - JOUR
T1 - Presence, origins and effect of stable surface hydration on regenerated cellulose for underwater oil-repellent membranes
AU - Justin Koh, J.
AU - Pang, Pengfei
AU - Chakraborty, Souvik
AU - Kong, Junhua
AU - Sng, Anqi
AU - Anukunwithaya, Patsaya
AU - Huang, Shujuan
AU - Koh, Xue Qi
AU - Thenarianto, Calvin
AU - Thitsartan, Warintorn
AU - Daniel, Dan
AU - He, Chaobin
N1 - 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.
PY - 2023/4
Y1 - 2023/4
N2 - 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.
AB - 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.
KW - Membrane
KW - Oil/water separation
KW - Regenerated cellulose
KW - Surface hydration
KW - Underwater oil-repellency
UR - http://www.scopus.com/inward/record.url?scp=85145265516&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2022.12.109
DO - 10.1016/j.jcis.2022.12.109
M3 - Article
C2 - 36587573
AN - SCOPUS:85145265516
SN - 0021-9797
VL - 635
SP - 197
EP - 207
JO - Journal of colloid and interface science
JF - Journal of colloid and interface science
ER -