Quasi-Liquid Surfaces for Sustainable High-Performance Steam Condensation

Area of Science:

• Materials Science
• Chemical Engineering
• Thermodynamics

Background:

• Dropwise condensation offers superior heat-transfer coefficients compared to filmwise condensation.
• Existing methods for promoting dropwise condensation (superhydrophobic, liquid-infused surfaces) face significant durability challenges.
• Sustainable and durable surfaces are crucial for efficient steam condensation in water and energy systems.

Purpose of the Study:

• To develop a novel, durable surface capable of sustainable high-performance dropwise condensation.
• To investigate the heat-transfer characteristics and durability of quasi-liquid surfaces for steam condensation.
• To address the limitations of current superhydrophobic and liquid-infused surfaces.

Main Methods:

• Chemically bonding quasi-liquid polymer molecules onto solid substrates to create quasi-liquid surfaces.
• Characterizing surface properties, including contact angle hysteresis.
• Measuring heat-transfer coefficients under continuous steam condensation conditions.
• Assessing the long-term durability of the quasi-liquid surfaces.

Main Results:

• The developed quasi-liquid surfaces demonstrated ultralow contact angle hysteresis (down to 1°).
• Heat-transfer coefficients were significantly higher (up to 70% and 380%) compared to conventional hydrophobic and hydrophilic surfaces.
• A sustained heat-transfer coefficient of 71 kW/(m² K) was achieved at a heat flux of 420 kW/m² over 39 hours.
• The quasi-liquid surfaces exhibited extraordinary durability, overcoming limitations of previous approaches.

Conclusions:

• Quasi-liquid surfaces offer a sustainable and durable solution for high-performance dropwise steam condensation.
• These surfaces effectively minimize adhesion and enhance heat transfer, showing great potential for energy and water systems.
• The developed material addresses the critical long-standing durability challenge in dropwise condensation technology.