A polydimethylsiloxane-based sponge for water purification and interfacial solar steam generation

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Developing low-cost, novel porous materials is crucial for applications like solar desalination and liquid recycling.
• Efficient recovery of liquids and continuous solar steam generation require advanced material designs.

Purpose of the Study:

• To design and synthesize a polydimethylsiloxane-based sponge with a 3D interconnected porous structure.
• To evaluate the sponge's performance in liquid recovery and interfacial solar steam generation (ISSG).

Main Methods:

• Fabrication of a polydimethylsiloxane sponge with a web-like 3D porous structure.
• Testing the sponge's directional liquid transport capabilities based on temperature-dependent wettability.
• Evaluating solar steam generation efficiency, evaporation rate, and ion rejection from seawater.

Main Results:

• The sponge demonstrated directional transport of oil/organic solvents above 32°C and controlled desorption below 28°C.
• Achieved high light absorption (>95%) and light-to-heat conversion efficiency (99.87%), resulting in a seawater evaporation rate of 1.66 Kg m⁻²h⁻¹.
• The sponge exhibited self-regeneration, maintained high evaporation rates for 5 days, and achieved >99.6% ion rejection.

Conclusions:

• The developed sponge is effective for liquid recovery and continuous interfacial solar steam generation.
• Its properties facilitate self-regeneration, reversible wettability switching, and efficient water purification.
• The material shows significant potential for environmental restoration, metal recovery, and water regeneration.