Controlled Deposition of Nanosize and Microsize Particles by Spin-Casting

Area of Science:

• Materials Science
• Chemical Engineering
• Surface Science

Background:

• Hydrodynamic-evaporative spin-casting is a method for depositing spherical particles onto solid substrates.
• Particle coverage depends on processing parameters like concentration and particle size.
• Existing theories for polymer solution spin-casting are insufficient for larger particles.

Purpose of the Study:

• To investigate particle behavior during spin-casting.
• To understand factors influencing final particle coverage (Γ).
• To develop an improved theoretical model for particle deposition.

Main Methods:

• Studying the deposition of nanosize and microsize spherical particles.
• Analyzing particle behavior and coverage during spin-casting.
• Comparing experimental results with existing and a new theoretical approach.

Main Results:

• The existing theory accurately describes deposition for particles up to a few micrometers.
• The basic theory fails for larger particles due to size effects and sedimentation.
• A corrected theoretical approach accounting for particle size and sedimentation was developed.

Conclusions:

• Particle size and sedimentation significantly impact deposition coverage in spin-casting.
• The new theoretical model successfully explains and predicts experimental findings for a wider range of particle sizes.
• This research offers enhanced understanding and predictive capability for particle dispersion spin-casting processes.