Multi-scale porosity and transport phenomena

Study and control of the porosity within materials.

Team Leader
Michaela Klotz
Saint-Gobain Research Scientist
contact:  Michaela.Klotz@saint-gobain.com

Topics of Research

One of the topics of interest of the laboratory is the manufacture of materials with one or more controlled porosities, not only in size (micro: <2nm, meso: between 2-50nm and macro: > 50nm), but also in tortuosity and connectivity. Our main shaping tool is ice-templating. This process uses the growth of ice crystals to control the redistribution of suspended particles. In particular, ice-templating allows the formation of macropores which are the imprint left by ice crystals after sublimation. Controlling the ice growth directly controls the shape and direction of the macropores in the final material. The adjacent image shows an Alumina (in white) sample with a straight macroporosity (in gray) obtained by unidirectional freezing.

SEM micrograph of a macroporous Alumina, from [3].

This process can further be combined with surfactant self-assembly mechanisms to form materials with ordered meso and macropores. Both porosities are formed in one step.[1] Moreover, zeolites can be added, forming materials with hierarchical porosities at all length scales.

Applications are in the area of catalysis and adsorbents. The efficiency of these materials largely depends on the transport of molecules in the multiscale porosity. We are mainly interested in the impact of macroscopy, and more particularly of oriented macroporosity obtained by ice-templating, using an experimental as well as numerical approach.[2]

Publications

[3] Hakouk, K. et al, Implementation of novel ice-templated materials for conversion of tars from gasification product gas, Fuel Processing Technology (2018) 181, 340–351
[2] Vanson, J-M. et al, Kinetic Accessibility of Porous Material Adsorption Sites Studied through the Lattice Boltzmann Method, Langmuir (2017), 33, 1405−1411
[1] Albouy, P-A. et al, Freezing-induced self-assembly of amphiphilic molecules, Soft Matter, (2017), 13, 1759-1763

Team
 
 
Michaela Klotz Saint-Gobain Research Scientist Michaela.Klotz@saint-gobain.com
Former Members

Alexey Novikov

 

Postdoctoral Fellow

Alejandra Bueno PhD Student
Jérémy Dhainaut Postdoctoral Fellow
Jean-Matthieu Vanson PhD Student
Khadija Hakouk Postdoctoral Fellow