Controlling ice formation on gradient wettability surface for high-performance bioinspired materials.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Ice-templating is a promising technique for creating bioinspired materials.
• Controlling ice nucleation and growth is critical for material architecture but remains challenging.
• Existing methods lack precise control over these freezing parameters.

Purpose of the Study:

• To demonstrate a method for controlling successive ice nucleation and preferential growth.
• To explore the use of wettability gradients for advanced ice-templating.
• To fabricate high-performance bioinspired materials with complex architectures.

Main Methods:

• Utilizing a cold finger with a precisely engineered wettability gradient.
• Applying linear, bilayer linear, and radial wettability gradients.
• Infiltrating the ice-templated porous structures with a secondary material.

Main Results:

• Achieved controlled successive ice nucleation and preferential growth.
• Fabricated bulk porous materials with long-range lamellar patterns using a linear gradient.
• Created nacre-mimetic composites with superior strength and toughness.
• Generated cross-aligned and circular lamellar structures using bilayer and radial gradients, respectively.

Conclusions:

• Surface wettability patterns offer rich designability for controlling ice-templating.
• This approach enables the fabrication of high-performance bulk materials with complex, bioinspired architectures.
• The method overcomes limitations of conventional freeze-casting techniques for creating intricate structures.