Related Experiment Video
Updated: Apr 24, 2026
07:57
Accurate Determination of the Equilibrium Surface Tension Values with Area Perturbation Tests
Published on: August 30, 2019
6.8K
Succinic acid in aqueous solution: connecting microscopic surface composition and macroscopic surface tension
Josephina Werner1, Jan Julin, Maryam Dalirian
1Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden. josephina.werner@physics.uu.se.
Physical Chemistry Chemical Physics : PCCP
|September 4, 2014
Summary
Succinic acid concentrates at the water surface, unlike its deprotonated form. This surface enrichment explains the reduced surface tension in aqueous solutions, impacting atmospheric models.
Area of Science:
- Physical Chemistry
- Surface Science
- Computational Chemistry
Background:
- Understanding the behavior of molecules at interfaces is crucial for various scientific disciplines.
- The surface tension of aqueous solutions is a fundamental macroscopic property influenced by molecular interactions.
- Succinic acid's behavior at the air-water interface requires detailed investigation.
Purpose of the Study:
- To investigate the interfacial behavior of succinic acid in aqueous solutions.
- To quantify the surface excess concentration of succinic acid and its deprotonated form.
- To correlate surface enrichment with the reduction in surface tension.
Main Methods:
- Surface-sensitive X-ray photoelectron spectroscopy (XPS) for experimental analysis.
- Molecular dynamics (MD) simulations for detailed molecular-level insights.
- Varying pH and bulk concentrations to study different solution conditions.
Main Results:
- Succinic acid preferentially accumulates at the water-vapor interface.
- The deprotonated form of succinic acid is depleted from the surface due to hydration.
- Surface concentration of succinic acid was quantified and found to saturate the interface at high bulk concentrations.
- Enrichment factors were calculated and used to model surface tension reduction.
Conclusions:
- Succinic acid's surface activity is driven by its molecular structure, favoring the non-dissociated form at the interface.
- A direct correlation exists between succinic acid's surface enrichment and the observed decrease in surface tension.
- The findings provide microscopic insights into surface tension and have implications for atmospheric modeling.
Related Concept Videos
02:57Surface Tension, Capillary Action, and Viscosity
28.5K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.5K
01:16Surface Tension and Surface Energy
3.2K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
3.2K
01:22Surface Tension of Fluid
1.9K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
1.9K
01:27Surface Active Agents
149
Surfactants, named for their behavior at interfaces, positively adsorb at the interfaces of two phases, reducing interfacial tension. Their versatility as emulsifiers, detergents, and foaming agents stems from this ability. Surfactants, often termed amphiphiles, share the property of amphipathy, with molecules having both hydrophilic and hydrophobic portions. The hydrophilic part is called the head, and the hydrophobic part, including an elongated alkyl substituent, forms the tail.Surfactants...
149
01:13Contact Angle
27.7K
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces.
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
27.7K
01:19Composition of Polyprotic Acid Solutions as a Function of pH
1.2K
Polyprotic acids of the type H2M constitute two ionizable protons. As a result, on titration with a base, they exhibit two equivalence points in the titration curve. During titration, the species H2M, HM−, and M2− will be present in the solution at different points. The fractions of H2M, HM−, and M2− present at the various instances of the titration are denoted by α0, α1, and α2, respectively.
A graph with the alpha values is plotted against the volume of...
A graph with the alpha values is plotted against the volume of...
1.2K