Thuy Linh Phi: Conception of platform materials based on self-assembly between biosurfactants and cellulose

Abstract: 

The doctoral thesis investigates how cellulose nanocrystals, renewable nanoparticles obtained from plant fibers, can be combined with biosurfactants produced by microbial fermentation to create fully bio-based and sustainable materials. Although cellulose nanocrystals are strong, biodegradable, and widely available, their practical use is often limited by difficulties in dispersion, stability, and controlled gel formation. The purpose of this research was therefore to understand whether biosurfactants can improve these properties while keeping the materials simple, renewable, and environmentally friendly. The results show that biosurfactants can effectively stabilize cellulose nanocrystal dispersions, enhance the mechanical strength and responsiveness of cellulose-based hydrogels, and reduce the threshold required for gel formation. In doing so, the thesis provides one of the first systematic demonstrations that biosurfactants can act as versatile, fully bio-based agents to control cellulose nanocrystal behavior. This work is relevant to ongoing research in sustainable materials, soft matter physics, and green chemistry, all of which aim to replace fossil-based plastics with renewable alternatives. The findings can be applied in the design of biodegradable packaging, biomedical hydrogels, coatings, and other advanced materials that currently rely on petroleum-based polymers. Overall, the study concludes that biosurfactants offer a practical and renewable strategy to overcome key limitations of cellulose nanocrystals, laying the groundwork for the rational design of high-performance, fully bio-based materials for real-world sustainable applications.

Key words: cellulose nanocrystals, biosurfactants, colloidal stability, multicomponent hydrogels, sol-gel transition

Opponents: Dr. Bernard Cathala, Director of the BIA Unit, France, and Prof. Cosima Stubenrauch, Stuttgart University, Germany

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

Link to electronic thesis: LINK

Link to the remote defense: LINK