A simple and environment-friendly approach for synthesizing macroporous polymers from aqueous foams

Area of Science:

• Materials Science
• Polymer Chemistry
• Environmental Science

Background:

• Macroporous polymers are essential for applications like wastewater treatment.
• Conventional methods for creating macroporous polymers can be complex or environmentally unfriendly.

Purpose of the Study:

• To develop a facile and environmentally friendly method for preparing macroporous polyacrylamide (PAM).
• To investigate the role of surface-modified silica nanoparticles in stabilizing aqueous foams for polymerization.
• To explore the tunability of pore structure in the resulting macroporous polymers.

Main Methods:

• Utilizing surface-modified silica nanoparticles (using CTAB) to stabilize aqueous foams.
• Employing thermal-initiated polymerization of these stabilized foams.
• Characterizing the morphology and pore structure using Scanning Electron Microscopy (SEM).

Main Results:

• Macroporous polyacrylamide (PAM) was successfully synthesized via thermal polymerization of stabilized aqueous foams.
• Silica nanoparticle wettability, solid content, and air volume fraction influenced air bubble size and distribution.
• Tunable pore and pore throat sizes were achieved by adjusting silica content and air volume fraction.
• A high porosity of 83% was obtained with a 65% air volume fraction.

Conclusions:

• The proposed method provides a novel route to macroporous polymers with controlled structures.
• PAM hydrogels produced via this foam polymerization exhibit superior performance in wastewater treatment compared to emulsion-derived counterparts.
• This strategy is adaptable for synthesizing various macroporous polymers with tailored pore architectures.