Hydrophobic Aerogels from Vinyl Polymers Derived from Radical Polymerization: Proof-of-Concept

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Bio-based aerogels often exhibit hydrophilicity, limiting their applications.
• Developing hydrophobic alternatives is crucial for expanding the utility of these sustainable materials.

Purpose of the Study:

• To synthesize novel, water-repellent, mesoporous bio-based aerogels.
• To investigate the impact of different nonpolar ester groups in methacrylate monomers on aerogel properties.
• To achieve intrinsic hydrophobicity in bio-based aerogels.

Main Methods:

• Synthesis of cross-linked bio-based copolymers via methacrylate copolymerizations.
• Solvent exchange and supercritical drying for aerogel fabrication.
• Characterization of textural properties (porosity, density, surface area) and water contact angles.

Main Results:

• Aerogels exhibited high porosity (~96%) and low densities (0.07-0.11 g cm⁻³).
• Specific surface areas ranged from 120-240 m² g⁻¹, with mesoporous networks.
• Aerogels with vanillin ester groups showed stable hydrophobic contact angles (~100°), while others absorbed water.

Conclusions:

• The choice of methacrylate ester group significantly influences aerogel pore structure and hydrophobicity.
• A novel pathway to intrinsically hydrophobic bio-based aerogels was established.
• Monomer structure tailoring enables optimization of bio-based aerogel properties for specific applications.