Description

Foam-like materials are essential and widely used in daily life and industrial applications due to their lightweight, porous architecture, excellent mechanical energy-absorption capacity and low thermal conductivity. However, most commercially available foams are derived from petroleum-based materials, raising significant environmental and health concerns. This project targets the bio-based foams (biofoams) made from natural, renewable polymers such as polysaccharides, and provide a pathway toward a more sustainable and circular materials economy. The project will benefit from the strong expertise in biopolymer gelation, rheology, and soft matter physics at the LRP, complemented by collaborations with the physicochemistry laboratory CERMAV.

Precisely engineering the architecture of biofoams remains challenging. The simplest and most cost-effective approach relies on creating a liquid foam precursor by dispersing gas into a biopolymer solution, where the bubble size is expected to determine the pore size of the biofoam. In practice, however, this strategy is hindered by a critical bottleneck: liquid foams are mechanically weak and prone to destabilization through bubble coalescence, coarsening, and liquid film drainage. These consequences ultimately lead to foam collapse and poor control over the final porous structure. To overcome this limitation, the central strategy of this project is to reinforce bubble interfaces and inter-bubble liquid films by tunable biopolymer gelation.

The core scientific question is how to control biopolymer gelation kinetics at gas-liquid interfaces and within thin liquid films, and how this control can be harnessed to tailor bubble dynamics in foam generation. Gelation in foams occurs in a complex and highly confined environment. Gas–liquid interfaces impose strong constraints on the mobility, conformation, and assembly of biopolymers, leading to gelation kinetics that might differ from those in the bulk phase. The first objective of the project is therefore to elucidate the mechanisms of gelation kinetics at interfaces and in thin liquid films within biofoams. Moreover, biopolymer gelation can occur over a wide range of timescales, from seconds to hours or even days. The second objective is to investigate how gelation kinetics compete with and influence foam dynamics such as bubble coalescence, coarsening, and drainage.

To address these objectives, the project adopts a bottom-up experimental approach. First, a dedicated microrheology setup will be developed to decouple interfacial rheology from the rheology of the thin liquid films. This enables independent characterization of gelation kinetics at interfaces and in the confined bulk. Second, a microfluidic platform will be designed to enable real-time visualization and quantification of bubble dynamics in the presence of tunable gelation learned from the first step. This approach will directly link gelation kinetics to pore size control in the biofoams.

Overall, this project leverages fundamental insights into biopolymer gelation kinetics to control the architecture and mechanical properties of biofoams, bridging the fields of materials science, soft matter physics, and engineering. The knowledge developed in this project are expected to pave the way toward scalable biofoam production for applications such as packaging, thermal insulation, and energy absorption.

Compétences requises

Formation générale de bon niveau scientifique en physique, physico-chimie ou mécanique. Appétence pour le travail expérimental. Analyse d'image et de données. Travail en équipe. Maitrise de l'anglais. Expérience dans le milieu de la recherche.

Bibliographie

[1] S. Andrieux, A. Quell, C. Stubenrauch, and W. Drenckhan. Liquid foam templating–A route to tailor-made polymer foams. Advances in colloid and interface science 256 (2018): 276-290.
[2] Z. A. AlYousef, M. A. Almobarky, and D. S. Schechter. The effect of nanoparticle aggregation on surfactant foam stability. Journal of colloid and interface science 511 (2018): 365-373.
[3] P.-G. de Gennes, F. Brochard-Wyart, and D. Quéré. Capillarity and wetting phenomena: drops, bubbles, pearls, waves. Springer Science & Business Media, 2003.
[4] D. Varade, D. Carriere, L. R. Arriaga, A. L. Fameau, E. Rio, D. Langevin, and W. Drenckhan. On the origin of the stability of foams made from catanionic surfactant mixtures. Soft Matter, 7.14 (2011): 6557-6570.
[5] J. N. Miquelim, S. C. Lannes, and R. Mezzenga. pH Influence on the stability of foams with protein–polysaccharide complexes at their interfaces. Food hydrocolloids 24.4 (2010): 398-405.
[6] A. Barbetta, G. Rizzitelli, R. Bedini, R. Pecci, and M. Dentini. Porous gelatin hydrogels by gas-in-liquid foam templating. Soft Matter 6.8 (2010): 1785-1792.
[7] E. Guilbert, C. de Loubens, A. Vilotte, C. Schmitt, D. Gunes, and H. Bodiguel. Spontaneous structuration of biohydrogels by membrane‐free osmosis. Advanced Functional Materials 34.34 (2024): 2400888.
[8] Y. Liu, W. J. Zhao, J. L. Li, and R. Y. Wang. Distinct kinetics of molecular gelation in a confined space and its relation to the structure and property of thin gel films. Physical Chemistry Chemical Physics 17.12 (2015): 8258-8265.
[9] R. Chachanidze, K. Xie, H. Massaad, D. Roux, M. Leonetti, and C. de Loubens. Structural characterization of the interfacial self-assembly of chitosan with oppositely charged surfactant. Journal of Colloid and Interface Science 616 (2022): 911-920.
[10] S. Vandebril, A. Franck, G. G. Fuller, P. Moldenaers, and J. Vermant. A double wall-ring geometry for interfacial shear rheometry. Rheologica Acta 49.2 (2010): 131-144.
[11] E. Chatzigiannakis, P. Veenstra, D. T. Bosch, and J. Vermant. Mimicking coalescence using a pressure-controlled dynamic thin film balance. Soft Matter 16.41 (2020): 9410–9422.
[12] K. Xie, M. Corpart, A. Deblais, and D. Bonn. Drop-drop coalescence: A simple crossover function between inertial and viscous dynamics. Physical Review Applied 23.6 (2025): 064014.

Mots clés

Rhéologie, Biomatériaux, Matière molle, Microfluidique