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Updated: Jul 16, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

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Published on: September 26, 2016

Approximate rate constants for nonideal diffusion and their application in a stochastic model.

Jeffrey W Bullard¹

¹Materials and Construction Research Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8615, USA.

The Journal of Physical Chemistry. A

|March 29, 2007

Summary

This study presents diffusion rate constants for nonideal solutions, using a random walker model to accurately capture solution nonidealities. The approach demonstrates ideal and nonideal solute diffusion, with potential for simulating advection and concentrated solutions.

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Last Updated: Jul 16, 2026

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The Diffusion of Passive Tracers in Laminar Shear Flow

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Published on: May 1, 2018

Area of Science:

Physical Chemistry
Computational Chemistry
Chemical Engineering

Background:

Understanding solute diffusion in nonideal solutions is crucial for various chemical processes.
Existing models may not fully capture the complexities of nonideal solution behavior.
Spatially varying potential fields add another layer of complexity to diffusion modeling.

Purpose of the Study:

To present and justify expressions for diffusion rate constants in dilute nonideal solutions.
To demonstrate the accuracy of a random walker model in capturing solution nonidealities.
To explore the simulation of advection and potential extensions to concentrated solutions.

Main Methods:

Derivation and review of rate constant expressions for diffusion.
Application of a random walker model incorporating derived rate constants.
Simulation of ideal solute diffusion, nonideal diffusion of nonelectrolytes and electrolytes.
Description of advection simulation and strategies for concentrated solutions.

Main Results:

Validated expressions for diffusion rate constants in nonideal solutions.
Demonstrated accurate capture of solution nonidealities using the random walker model.
Presented examples of ideal and nonideal solute diffusion in aqueous systems.

Conclusions:

The random walker model effectively simulates diffusion in nonideal solutions, including potential fields.
The approach provides a robust method for studying solute transport phenomena.
Further research can extend this model to more complex and concentrated solution scenarios.