Roozbeh Abidnejad: Particle-stabilized foams as advanced materials for energy management

Abstract: 

Buildings, packaging, and many everyday products rely on plastic foams for insulation and protection. While effective, these materials are typically made from fossil resources and can pose serious fire and environmental risks. This doctoral thesis explores sustainable alternatives by developing lightweight foams made from renewable nanocellulose and inorganic particles. The research focuses on particle-stabilized (Pickering) foams, where tiny solid particles replace conventional surfactants to stabilize air bubbles in water. By combining cellulose nanofibers with silica nanoparticles, the study demonstrates how stable wet foams can be transformed into solid, highly porous materials with very low density. The aim was to create multifunctional foams that not only insulate against heat, but also improve fire safety and enable thermal energy storage. The results show that these bio-based foams can achieve thermal insulation comparable to commercial polymer foams while offering improved fire performance, including self-extinguishing behavior and reduced toxic gas release. By incorporating phase-change materials such as polyethylene glycol into the foam structure, the materials can also store and release heat, helping to regulate temperature fluctuations. A key outcome of the research is a fundamental understanding of how nanocellulose and particles work together at air–water interfaces to control foam stability, structure, and performance. The thesis demonstrates that insulation, fire resistance, and thermal energy storage can be integrated into a single, renewable material platform. These findings are relevant to researchers and industries working on sustainable construction materials, energy-efficient packaging, and thermal management systems. The developed foams offer a promising route toward safer, multifunctional, and environmentally responsible alternatives to conventional plastic foams.

Key words: Foams, Pickering foams, Nanocellulose, Thermal energy storage, Sustainable materials

Opponent: Dr. Gilberto Siqueira, EMPA, Switzerland

Custos: Prof. Eero Kontturi, Aalto University School of Chemical Engineering

Link to electronic thesis: LINK

Link to the remote defense: LINK