Charge Transfer Altered by Particle Deposition as a Contact Line Moves over a Hydrophobic Surface

Area of Science:

• Physical Chemistry
• Surface Science
• Triboelectricity

Background:

• Aqueous three-phase contact line movement on hydrophobic surfaces causes electrical charge transfer (slide electrification).
• The influence of suspended particles on this phenomenon is not fully understood.

Purpose of the Study:

• To investigate how nanoparticles in an aqueous solution affect charge transfer during slide electrification.
• To elucidate the mechanisms behind particle-induced alterations in slide electrification.

Main Methods:

• Experimental observation of charge transfer during the movement of a contact line over a hydrophobic surface with varying concentrations of TiO2 and carbon nanoparticles.
• Correlation analysis between particle area coverage and measured charge transfer.
• Development of a theoretical model to explain observed phenomena.

Main Results:

• TiO2 nanoparticle concentration in water inversely correlates with charge transfer, leading to near-exponential decay with increased particle area coverage.
• Carbon nanoparticles initially increase charge transfer before decay, despite monotonic increase in area coverage.
• Observed behaviors are linked to particle adhesion, area coverage, and potential ion release.

Conclusions:

• Particle adhesion and area coverage significantly modify slide electrification.
• Ion release from the electrical double layer can play a crucial role in charge transfer dynamics, especially with certain particle types like carbon.