Back to Search Start Over

Exclusion Zone Phenomena in Water-A Critical Review of Experimental Findings and Theories.

Authors :
Elton DC
Spencer PD
Riches JD
Williams ED
Source :
International journal of molecular sciences [Int J Mol Sci] 2020 Jul 17; Vol. 21 (14). Date of Electronic Publication: 2020 Jul 17.
Publication Year :
2020

Abstract

The existence of the exclusion zone (EZ), a layer of water in which plastic microspheres are repelled from hydrophilic surfaces, has now been independently demonstrated by several groups. A better understanding of the mechanisms which generate EZs would help with understanding the possible importance of EZs in biology and in engineering applications such as filtration and microfluidics. Here we review the experimental evidence for EZ phenomena in water and the major theories that have been proposed. We review experimental results from birefringence, neutron radiography, nuclear magnetic resonance, and other studies. Pollack theorizes that water in the EZ exists has a different structure than bulk water, and that this accounts for the EZ. We present several alternative explanations for EZs and argue that Schurr's theory based on diffusiophoresis presents a compelling alternative explanation for the core EZ phenomenon. Among other things, Schurr's theory makes predictions about the growth of the EZ with time which have been confirmed by Florea et al. and others. We also touch on several possible confounding factors that make experimentation on EZs difficult, such as charged surface groups, dissolved solutes, and adsorbed nanobubbles.

Details

Language :
English
ISSN :
1422-0067
Volume :
21
Issue :
14
Database :
MEDLINE
Journal :
International journal of molecular sciences
Publication Type :
Academic Journal
Accession number :
32708867
Full Text :
https://doi.org/10.3390/ijms21145041