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Nanobubble boundary layer thickness quantified by solvent relaxation NMR
- Source :
- Journal of Colloid and Interface Science. 609:637-644
- Publication Year :
- 2022
- Publisher :
- Elsevier BV, 2022.
-
Abstract
- Hypothesis The boundary layer holds the key to solve the puzzle of the unusual stability of the nanobubbles in solution. The quantitative determination on its mechanical and structural properties has not been achieved due to its diffusive and dynamic nature, lack of distinctive interfaces, and difficult differentiation from bulk background. Therefore, it is necessary to investigate this boundary using more sensitive interface analysis technologies to effectively differentiate the water molecules at the interface from those in the bulk. Experiments An in-situ and non-deconstructive method, solvent relaxation nuclear magnetic resonance, was used to investigate the boundary layer on bulk nanobubbles, where the relaxation rate of the water in the layer and its thickness were measured by solvent relaxation NMR and the ratio between the water molecules at the bubble interfaces and those in the bulk and the corresponding boundary layer thickness were determined. Findings The spin-spin relaxation time for the water in the layer (∼101ms) is found to be two orders of magnitude lower than that of the free water (∼103ms). As the first attempt, the determined boundary layer thickness is around 35-45 nanometers and 17.0 %-8.7 % of the effective gaseous size of the nanobubbles, which increases with the decrease of the bubble diameter. As a result, a quantitative measurement model for bubble boundary layer has been established in order to better understand the interfacial properties and stabilization mechanism for bulk nanobubbles.
- Subjects :
- Magnetic Resonance Spectroscopy
Materials science
Bubble
Relaxation (NMR)
Water
Boundary (topology)
Boundary layer thickness
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Diffusion
Biomaterials
Boundary layer
Colloid and Surface Chemistry
Chemical physics
Solvents
Nanometre
Gases
Layer (electronics)
Order of magnitude
Subjects
Details
- ISSN :
- 00219797
- Volume :
- 609
- Database :
- OpenAIRE
- Journal :
- Journal of Colloid and Interface Science
- Accession number :
- edsair.doi.dedup.....08c2f9cd232966c55de2a8d8ce711a48