Electrophoretic mobility of spherical particles in bounded domain

Area of Science:

• Physical Chemistry
• Fluid Dynamics
• Colloid Science

Background:

• Electrophoretic motion of particles in fluidic channels is crucial in various applications.
• Classical theories often fail to accurately predict particle behavior with nonsymmetric electrolytes and confinement effects.
• Previous 3D steady-state models require enhancement to address complex ionic environments.

Purpose of the Study:

• To improve a 3D steady-state model of electrophoretic motion for spherical particles in bounded fluidic channels.
• To incorporate the effects of nonsymmetric electrolytes and electrical double-layer (EDL) polarization.
• To validate the enhanced model against experimental data for particle mobilities and zeta potentials.

Main Methods:

• Developed an improved 3D steady-state model for particle electrophoresis.
• Included nonsymmetric electrolytes, EDL polarization, and channel confinement effects.
• Validated the model using experimental particle mobility data from Semenov et al. (2013), Napoli et al. (2011), and Wynne et al. (2012).

Main Results:

• The enhanced model accurately predicts particle zeta potentials and mobilities, showing good agreement with experimental data.
• Demonstrated the model's applicability to conditions where classical theory is insufficient, such as high zeta potentials in bounded channels with nonsymmetric electrolytes.
• Observed increased particle mobility with complex ion compositions and specific buffer solutions (phosphate, borate) compared to simple symmetric electrolytes.

Conclusions:

• The improved 3D model provides a more accurate prediction of electrophoretic motion in complex electrolyte solutions and confined geometries.
• The model's validation against experimental data confirms its utility for a wider range of practical applications.
• Understanding the influence of nonsymmetric electrolytes and buffer solutions is critical for optimizing electrophoretic separations and analyses.