Related Experiment Video
Updated: Aug 7, 2026
08:19
Induction of Microstreaming by Nonspherical Bubble Oscillations in an Acoustic Levitation System
Published on: May 9, 2021
Proton transfer between organic acids and bases at the acoustic bubble-aqueous solution interface
Muthupandian Ashokkumar1, Franz Grieser
1Particulate Fluids Processing Centre, School of Chemistry, University of Melbourne, VIC 3010, Australia.
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Multibubble sonoluminescence (MBSL) intensity is unchanged in pure water or when organic acids/bases are ionized. Un-ionized solutes and mixtures significantly suppress MBSL intensity by reducing bubble collapse temperatures.
Area of Science:
- Physical Chemistry
- Acoustics
- Chemical Thermodynamics
Background:
- Multibubble sonoluminescence (MBSL) is a phenomenon where acoustic cavitation in liquids generates light.
- The intensity of MBSL is influenced by the chemical composition of the liquid medium.
- Understanding solute effects on MBSL is crucial for applications in sonochemistry and materials science.
Purpose of the Study:
- To investigate the effect of pH on MBSL intensity in aqueous solutions of organic acids and bases.
- To elucidate the mechanism of MBSL suppression in mixed solute systems.
- To explore the role of solute ionization state and interfacial proton transfer in MBSL.
Main Methods:
- Experimental measurement of MBSL emission intensity from aqueous solutions.
- Systematic variation of pH for solutions containing organic acids (RCOOH) and bases (RNH2).
- Analysis of MBSL intensity in mixed acid-base solute systems.
Main Results:
- MBSL intensity in pure water or ionized acid/base solutions (RCOO-, RNH3+) is similar.
- Un-ionized organic acids or bases suppress MBSL intensity.
- Mixed RCOO- and RNH3+ solutions (pH 7-9) show significant MBSL suppression compared to water.
Conclusions:
- Interfacial proton transfer between adsorbed acid-base complexes ([RCOO-...RNH3+]) occurs during bubble collapse.
- Formation of neutral solutes reduces bubble core temperature, thus suppressing MBSL intensity.
- The observed MBSL suppression is attributed to altered bubble dynamics and thermodynamics at the interface.
Related Concept Videos
02:16Brønsted-Lowry Acids and Bases
In 1923, the Brønsted–Lowry definition of acids and bases was proposed by Johannes Brønsted and Thomas Lowry. According to this theory, a Brønsted acid is defined as a species that donates a proton in a chemical reaction and gets converted to its conjugate base. A Brønsted base is defined as a species that accepts a proton in a chemical reaction and gets converted into its conjugate acid. These transfers of protons are caused by the displacement of electrons in these reactions, which is...
01:29Leveling Effect
In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the solvent...
02:58Bronsted-Lowry Acids and Bases
The acid-base reaction class has been studied for quite some time. In 1680, Robert Boyle reported traits of acid solutions that included their ability to dissolve many substances, to change the colors of certain natural dyes, and to lose these traits after coming in contact with alkali (base) solutions. In the eighteenth century, it was recognized that acids have a sour taste, react with limestone to liberate a gaseous substance (now known to be CO2), and interact with alkalis to form neutral...
01:16Titration in Nonaqueous Solvents
Most acid-base titrations are performed in an aqueous medium. In aqueous titrations, water competes with weaker acids or bases for proton donation or acceptance, leading to ambiguous endpoints in the titration curve. Water also affects the partial ionization of weak acids or bases. For example, water accepts a proton from acetic acid to form hydronium and acetate ions. The hydronium ion formed is a stronger acid than acetic acid, and the acetate ion is a stronger base than water. As a result,...
02:12Solvating Effects
An understanding of the solvating effect helps rationalize the relation between solvation and acidity of the compound. In addition, this also explains the relative stability of conjugate bases for compounds with different pKa values. This lesson details, in-depth, the principle of solvating effects. The strength of an acid and the stability of its corresponding conjugate base are determined using pKa values. This observed relationship is a consequence of solvation, which is the interaction...
01:01Acid Halides to Carboxylic Acids: Hydrolysis
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...