Breath figure patterns prepared by spin coating in a dry environment

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Breath figure patterns are crucial for creating porous polymer films.
• Conventional methods for generating these patterns often require specific humidity levels.
• Developing a more versatile fabrication technique is essential for broader applications.

Purpose of the Study:

• To introduce a novel spin-coating method for fabricating breath figure patterns.
• To demonstrate the generation of controllable pore sizes on homopolymer films.
• To establish a convenient and scalable approach for porous film fabrication.

Main Methods:

• Spin coating of homopolymer solutions (cellulose acetate butyrate, polystyrene, poly(methyl methacrylate)) in various solvents.
• Utilizing water-miscible solvents like tetrahydrofuran (THF).
• Generating breath figure patterns under controlled environments, including dry conditions with added water to THF.

Main Results:

• Successfully generated breath figure patterns using spin coating with THF, even in low humidity.
• Achieved pore sizes ranging from a few hundred nanometers to several micrometers.
• Demonstrated that pore size increases with water content in THF and decreases with rotational speed.

Conclusions:

• The novel spin-coating method offers a convenient alternative to conventional breath figure pattern fabrication.
• This technique allows for precise control over pore size by adjusting water content and spin speed.
• The method is suitable for fabricating large-scale porous polymer films with diverse pore characteristics.