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Updated: Sep 13, 2025
Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
Surface Activity of n-Carboxylic Acids.
Duc Toan Truong1,2, Chi M Phan3
1Laboratory for Chemical Computation and Modeling, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City 70000, Vietnam.
Carboxylic acid ionization is significantly enhanced at air/water surfaces, lowering surface pKa. This surface activity increases with carbon chain length, impacting aerosol properties and climate.
Area of Science:
- Physical Chemistry
- Surface Science
- Environmental Chemistry
Background:
- Carboxylic acids exhibit unique behavior at interfaces.
- Understanding surface ionization is crucial for atmospheric chemistry.
Purpose of the Study:
- To model and explain the ionization of carboxylic acids at the air/water surface.
- To correlate acid structure with surface activity and ionization enhancement.
Main Methods:
- Combined computational simulation with reported experimental data.
- Developed a model based on surface affinity increments per CH2 group.
Main Results:
- Model accurately predicts surface ionization for acids from formic to hexanoic.
- Acid ionization is massively enhanced at the surface, lowering the surface pKa.
- Surface enhancement increases linearly with carbon chain length.
Conclusions:
- The study clarifies century-old analyses by Traube and Langmuir.
- Provides insights into surface enthalpy of polar molecules, explaining Stefan's rule deficits.
- Enhanced surface activity of carboxylic acids has implications for aerosol properties and climate effects.
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