Gradual Morphological Tuning in Polymer Microspheres via Pickering Emulsion Synthesis: Architecture-Controlled Dye...

Area of Science:

• Materials Science
• Polymer Chemistry
• Environmental Science

Background:

• Polymeric microspheres are tunable platforms for dye adsorption.
• Pickering emulsion polymerization enables structural control over microspheres.
• Methylene blue is a common model dye for water contamination studies.

Purpose of the Study:

• Investigate methylene blue adsorption on two types of polymeric microspheres (PM and PD).
• Model adsorption kinetics using a dual-process approach (diffusion and surface kinetics).
• Correlate adsorption mechanisms with microsphere architecture (pore size, particle size).

Main Methods:

• Synthesized poly(methacrylic acid) microspheres via Pickering emulsion polymerization.
• Characterized microspheres for micro- and nanoporosity.
• Applied a dual-process kinetic model to adsorption data.
• Analyzed correlations between adsorption rates and structural parameters.

Main Results:

• PM microspheres: diffusion dominant in small, macroporous particles; surface kinetics dominant in larger, less macroporous particles.
• PD microspheres: surface adsorption dominant in small particles; diffusion through nanopores relevant in larger particles.
• Strong inverse correlation between diffusion and kinetic components in PD particles, indicating competitive suppression.

Conclusions:

• Microsphere internal pore architecture critically controls adsorption mechanisms.
• Tuning particle size and porosity allows precise control over diffusion vs. surface kinetics.
• Rational design of microparticle adsorbents for efficient dye removal and water purification is achievable.