Hybrid microspheres and percolated monoliths synthesized via Pickering emulsion co-polymerization stabilized by in situ surface-modified silica nanoparticles

• Published in: Express polymer letters Vol. 15; no. 6; pp. 554 - 567
• Main Authors: Fouconnier, B., Lopez-Serrano, F., Puente Lee, R. I., Terrazas-Rodriguez, J. E., Roman-Guerrero, A., Barrera, M. C., Escobar, J.
• Format: Journal Article
• Language: English
• Published: Budapest Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering 01.06.2021; Budapest University of Technology
• Subjects: bijel; Clusters; Copolymerization; Copolymers; Crosslinking; Divinylbenzene; Emulsion polymerization; Hydrocarbons; Hydrophobicity; mechanisms; Microspheres; monolith; Morphology; nanocomposites; Nanoparticles; Particle size; pickering emulsion polymerization; Polymer blends; Polymers; Self-assembly; Silicon dioxide; Sodium; Mexico
• ISSN: 1788-618X; 1788-618X
• DOI: 10.3144/expresspolymlett.2021.47

The Pickering emulsion polymerization of styrene (St), divinylbenzene (DVB) as a crosslinking agent, and sodium 4-vinyl benzene sulfonate (VBS) used for in situ surface-modification of silica nanoparticles (SNps) was investigated. At 1.0 wt% DVB, amphiphilic SNps with hydrophobic patches were formed, further self-assembling into copolymer-SNps clusters occurred. Subsequently, these clusters grow by monomer swelling to finally lead to the formation of core-shell polymer microspheres. Unlike the hydrophilic patchy SNps, at 2.0 and 3.0 wt% DVB, surface-patterned SNps with higher effective hydrophobicity do not self-assemble in the water phase but rather lead to the formation of monoliths. The polymerization mechanisms related to the formation of polymer silica-coated microspheres hybrid-materials, or percolated monoliths with bi-continuous porosity, formed by interfacially jammed emulsion gel (bijels) templates, are discussed herein.