A fluctuation theory of liquid-phase solutions: Shear viscosity
Yury A Budkov1,2,3, Nikolai N Kalikin1,4, Petr E Brandyshev1,2
1Laboratory of Computational Physics, HSE University, Tallinskaya st. 34, 123458 Moscow, Russia.
The Journal of Chemical Physics
|July 8, 2025
Summary
This study presents a new theory for describing nonequilibrium liquid mixtures and calculating transport properties like shear viscosity. The approach extends existing methods to accurately model complex liquid systems.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Statistical Mechanics
Background:
- Describing liquids and mixtures beyond equilibrium, especially their transport properties, is a significant challenge.
- Existing theories often struggle with accurately modeling nonequilibrium liquid-phase systems.
Purpose of the Study:
- To introduce a novel phenomenological nonequilibrium theory for multicomponent liquid-phase solutions.
- To enable the calculation of transport properties, specifically shear viscosity, in these systems.
Main Methods:
- Developed a field-theoretical framework rooted in nonequilibrium statistical mechanics.
- Incorporated quasi-stationary concentration fluctuations, aligning with classical density functional theory.
- Extended the Dean-Kawasaki stochastic density functional theory for shear viscosity computation.
Main Results:
- Derived a general formula for shear viscosity in single-solute solutions.
- Successfully reproduced established results for various systems, including soft-core particles and hard spheres.
- Obtained new insights into the behavior of near-critical solutions and one-component plasma.
Conclusions:
- The proposed phenomenological theory provides an effective framework for nonequilibrium liquid mixtures.
- The method accurately calculates shear viscosity, validating its extension of existing theories.
- This approach advances the understanding of transport properties in complex liquid systems.
More Related Videos
08:42Challenges in Rheological Characterization of Highly Concentrated Suspensions — A Case Study for Screen-printing Silver Pastes
Published on: April 10, 2017
20.1K
08:02Fabricating High-viscosity Droplets using Microfluidic Capillary Device with Phase-inversion Co-flow Structure
Published on: April 17, 2018
10.6K
Related Concept Videos
01:18Newtonian Fluid: Problem Solving
405
Newtonian fluids exhibit a constant viscosity, meaning their shear stress and shear strain rate are directly proportional. This property ensures a predictable and stable response to applied forces, maintaining a linear relationship between force and flow. Examples include water, air, and light oils, consistently demonstrating this proportional behavior regardless of external conditions.
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
405
01:17Viscosity
6.2K
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
6.2K
02:57Surface Tension, Capillary Action, and Viscosity
29.4K
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...
29.4K
01:27Types of Fluids
500
Fluids can be classified into Newtonian and non-Newtonian fluids based on their response to shear stress. Newtonian fluids have a linear relationship between shear stress and the shear strain rate, following Newton's law of viscosity. Their viscosity remains constant regardless of the shear rate, making their behavior predictable and easier to analyze. Common examples include water, air, oil, and gasoline.
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and...
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and...
500
01:19Viscosity of Fluid
719
Viscosity measures the resistance a fluid offers to flow and deformation. It results from internal friction between layers of fluid moving relative to one another. Dynamic viscosity, denoted by the Greek letter mu (μ), quantifies the force needed to move one fluid layer over another. For Newtonian fluids like water and air, the relationship between the shearing stress and the rate of shearing strain is linear, meaning their viscosity remains constant regardless of the applied stress.
719
01:20Stokes' Law
1.7K
Viscous forces, like friction, are intermolecular forces that resist the relative motion of molecules over each other. When a solid body moves through a liquid, viscous forces drag it in the opposite direction. The force's magnitude depends on the solid's shape and size, as well as its speed and the liquid's coefficient of viscosity, density and temperature.
The expression for the force on a solid spherical object in a fluid is called Stokes' law. Stokes' law is valid only...
The expression for the force on a solid spherical object in a fluid is called Stokes' law. Stokes' law is valid only...
1.7K