Nanobubbles at the Interface between Water and a Hydrophobic Solid.

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Abstract Text:

A very thin layer (5-80 nm) of gas phase, consisting of discrete bubbles with only about 40 000 molecules, is quite stable at the interface between a hydrophobic solid and water. We prepare this gas phase from either ambient air or from CO2(g) through a solvent exchange method reported previously. In this work, we examine the interface using attenuated total internal reflection infrared spectroscopy. The presence of rotational fine structure in the spectrum of CO2 and D2O proves that molecules are present in the gas phase at the interface. The air bubbles are stable for more than 4 days, whereas the CO2 bubbles are only stable for 1-2 h. We determine the average gas pressure inside the CO2 bubbles from the IR spectrum in two ways: from the width of the rotational fine structure (Pgas < 2 atm) and from the intensity in the IR spectrum (Pgas = 1.1 +/- 0.4 atm). The small difference in gas pressure between the bubbles and the ambient (1 atm) is consistent with the long lifetime. The dimensions and curvature of a set of individual bubbles was determined by atomic force microscopy. The pressures of individual bubbles calculated from the measured curvature using the Laplace equation fall into the range Pgas = 1.0-1.7 atm, which is concordant with the average pressure measured from the IR spectrum. We believe that the difference in stability of the CO2 bubbles and the air bubbles is due to a combination of the much lower pressure of CO2 in the atmosphere and the greater solubility of CO2 in water, compared to N2 and O2. As expected, smaller bubbles have a shorter average lifetime than larger bubbles, and the average pressure and the curvature of individual bubbles decreases with time. Surface plasmon resonance measurements provide supporting evidence that the film is in the gas state: the thin film has a lower refractive index than water, and there are few common contaminants that satisfy this condition. Interfacial gas bubbles are not ubiquitous on hydrophobic solids: bubble-free and bubble-decorated hydrophobic interfaces can be routinely prepared.

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Publishing Authors By Initials

For similar abstracts research abstracts see: abstracts research

PUBMED ID PMID:

MEDLINE DATE:

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Journal Published:

PUBLICATION TYPE: Journal Article

Journal: Langmuir : the ACS journal of surfaces and colloid

VOLUME: 24

Page Numbers: 4756-64

Journal Abbreviation:

ISSN: 0743-7463

DAY: 27

MONTH: 03

YEAR: 2008

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 9882736

Nanobubbles at the Interface between Water and a Hydrophobic Solid. Keywords Mesh Terms:

KEYWORDS:

MESH TERMS:

Chemical & Substance for Abstract: Nanobubbles at the Interface between Water and a Hydrophobic Solid. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for Nanobubbles at the Interface between Water and a Hydrophobic Solid.

AFFILIATION: Department of Chemical and Biomolecular Engineering and Particulate Fluid Processing Center, University of Melbourne, Melbourne 3010, Australia.

Country: United States

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: Langmuir

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Nanobubbles at the Interface between Water and a Hydrophobic Solid Related Publications

• Adaptation of the small intestine--does it occur in man?
• Formation of Interfacial Nanodroplets through Changes in Solvent Quality.
• Immobilized enzymes as catalytically-active tools for nanofabrication.
• Indications for TPN in preterm babies.
• Interfacial oil droplets.
• Management of a physician's office.
• Nanobubbles at the Interface between Water and a Hydrophobic Solid.