Programmable Porous Polymers via Direct Bubble Writing with Surfactant-Free Inks

Area of Science:

• Polymer Chemistry
• Materials Science
• Additive Manufacturing

Background:

• Macroporous polymers with graded architecture/chemistry are valuable for acoustics, energy storage, electronics, and filtration.
• Current fabrication methods limit achieving these functional gradients.

Purpose of the Study:

• To introduce thiol-ene chemistries into direct bubble writing for advanced polymer foam fabrication.
• To demonstrate the capability of creating functional gradients in macroporous materials.

Main Methods:

• Utilized direct bubble writing with high-viscosity (410 cP), non-aqueous thiol-ene inks.
• Achieved surfactant-free and solvent-free foam fabrication without drying shrinkage.
• Operated at high liquid flow rates (3 mL min⁻¹).

Main Results:

• Successfully fabricated 3D graded polymer foams with controlled cell size, density, and shape.
• Demonstrated functionalities including shape memory and high glass transition temperatures (>25 °C).
• Showcased the creation of chemical gradients within the foams.

Conclusions:

• Direct bubble writing with thiol-ene inks is a versatile method for fabricating functional macroporous materials.
• This technique allows for rapid, one-step creation of materials with locally controlled chemical, mechanical, and architectural gradients.
• Expands direct bubble writing capabilities to non-aqueous formulations and high flow rates.