Details
| Original language | English |
|---|---|
| Article number | 134895 |
| Number of pages | 12 |
| Journal | Colloids and Surfaces A: Physicochemical and Engineering Aspects |
| Volume | 701 |
| Early online date | 22 Jul 2024 |
| Publication status | E-pub ahead of print - 22 Jul 2024 |
Abstract
Nanobubbles (NBs) and their derivative, bulk nanobubbles (BNBs), have been widely studied due to their potential wide range of applications. However, the stable existence of intrinsic NBs and BNBs in solutions is still controversial. This study investigates the existence and behaviour of unknown nano-entities in dilute alkaline solutions using Field-Flow Fractionation Multi-Angle Light Scattering (FFF-MALS), resulting in the first report of the presence, size distribution, and size distribution changes under different treatments. The results suggest that neutral and acidic pure solutions of salts at concentrations below the solubility product do not contain detectable nano entities. Alkaline solutions, on the other hand, such as carbonate buffer and sodium hydroxide, do contain nano scatterers in the range of ∼100 nm diameter that cannot be removed by boiling or filtration. Reducing the pH of the solutions or freezing reduces their number densities. The freeze-thaw procedure strongly suggests that these nano entities are BNBs. Zeta Nanoparticle Tracking Analysis (ZNTA) shows the zeta potential and the concentration in agreement with previous literature. It can be concluded that intrinsic BNBs in alkaline solutions are an integral part of the total nano-entity population. This study highlights the importance of considering intrinsic BNBs when investigating nanoparticles in alkaline solutions with analytical methods such as Static Light Scattering (SLS), which can detect low number densities in the original liquid state that may not be plausible by other detection methods due to their detection thresholds or acquisition of sample preparation methods of drying or freezing that do not allow real-time observations.
Keywords
- Alkaline solutions, Nanobubbles, Static light scattering, Zeta potential
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemical Engineering(all)
- Colloid and Surface Chemistry
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In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 701, 134895, 20.11.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Intrinsic CO2 nanobubbles in alkaline aqueous solutions
AU - Zarei, Talie
AU - Fuchs, Elmar C.
AU - Agostinho, Luewton L.F.
AU - Gebauer, Denis
AU - Woisetschläger, Jakob
AU - Offerhaus, Herman L.
N1 - Publisher Copyright: © 2024 The Authors
PY - 2024/7/22
Y1 - 2024/7/22
N2 - Nanobubbles (NBs) and their derivative, bulk nanobubbles (BNBs), have been widely studied due to their potential wide range of applications. However, the stable existence of intrinsic NBs and BNBs in solutions is still controversial. This study investigates the existence and behaviour of unknown nano-entities in dilute alkaline solutions using Field-Flow Fractionation Multi-Angle Light Scattering (FFF-MALS), resulting in the first report of the presence, size distribution, and size distribution changes under different treatments. The results suggest that neutral and acidic pure solutions of salts at concentrations below the solubility product do not contain detectable nano entities. Alkaline solutions, on the other hand, such as carbonate buffer and sodium hydroxide, do contain nano scatterers in the range of ∼100 nm diameter that cannot be removed by boiling or filtration. Reducing the pH of the solutions or freezing reduces their number densities. The freeze-thaw procedure strongly suggests that these nano entities are BNBs. Zeta Nanoparticle Tracking Analysis (ZNTA) shows the zeta potential and the concentration in agreement with previous literature. It can be concluded that intrinsic BNBs in alkaline solutions are an integral part of the total nano-entity population. This study highlights the importance of considering intrinsic BNBs when investigating nanoparticles in alkaline solutions with analytical methods such as Static Light Scattering (SLS), which can detect low number densities in the original liquid state that may not be plausible by other detection methods due to their detection thresholds or acquisition of sample preparation methods of drying or freezing that do not allow real-time observations.
AB - Nanobubbles (NBs) and their derivative, bulk nanobubbles (BNBs), have been widely studied due to their potential wide range of applications. However, the stable existence of intrinsic NBs and BNBs in solutions is still controversial. This study investigates the existence and behaviour of unknown nano-entities in dilute alkaline solutions using Field-Flow Fractionation Multi-Angle Light Scattering (FFF-MALS), resulting in the first report of the presence, size distribution, and size distribution changes under different treatments. The results suggest that neutral and acidic pure solutions of salts at concentrations below the solubility product do not contain detectable nano entities. Alkaline solutions, on the other hand, such as carbonate buffer and sodium hydroxide, do contain nano scatterers in the range of ∼100 nm diameter that cannot be removed by boiling or filtration. Reducing the pH of the solutions or freezing reduces their number densities. The freeze-thaw procedure strongly suggests that these nano entities are BNBs. Zeta Nanoparticle Tracking Analysis (ZNTA) shows the zeta potential and the concentration in agreement with previous literature. It can be concluded that intrinsic BNBs in alkaline solutions are an integral part of the total nano-entity population. This study highlights the importance of considering intrinsic BNBs when investigating nanoparticles in alkaline solutions with analytical methods such as Static Light Scattering (SLS), which can detect low number densities in the original liquid state that may not be plausible by other detection methods due to their detection thresholds or acquisition of sample preparation methods of drying or freezing that do not allow real-time observations.
KW - Alkaline solutions
KW - Nanobubbles
KW - Static light scattering
KW - Zeta potential
UR - http://www.scopus.com/inward/record.url?scp=85199778576&partnerID=8YFLogxK
U2 - 10.1016/j.colsurfa.2024.134895
DO - 10.1016/j.colsurfa.2024.134895
M3 - Article
AN - SCOPUS:85199778576
VL - 701
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
SN - 0927-7757
M1 - 134895
ER -