Three-Dimensional Coffee-Ring Effect Induced Deposition on Foam Surface for Enhanced Photothermal Conversion

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Uniform deposition of functional materials on porous substrates is crucial for interfacial applications.
• Melamine foam (MF) offers a high surface area but requires controlled functionalization.
• Existing methods often struggle with homogeneous deposition on porous structures.

Purpose of the Study:

• To develop a simple and robust method for uniform surface deposition on melamine foam.
• To investigate the role of polyvinyl alcohol (PVA) in enhancing deposition uniformity.
• To demonstrate the application of functionalized MF in solar desalination.

Main Methods:

• A polyvinyl alcohol (PVA)-mediated evaporation drying strategy was employed.
• The coffee-ring effect was enhanced using PVA to stabilize functional constituents.
• Core-shell MF structures were formed via 3D outward capillary flow and interfacial evaporation.

Main Results:

• Uniform surface deposition of molecules and colloidal particles on MF was achieved.
• Deposition thickness correlated positively with PVA concentration.
• The PVA/polypyrrole-coated MF exhibited enhanced interfacial photothermal and solar desalination performance.

Conclusions:

• The PVA-mediated evaporation drying strategy offers a facile route for uniform functionalization of porous foams.
• The resulting core-shell MF structures show promise for advanced interfacial applications, particularly in solar energy conversion and water treatment.