Wensen WANG
defended his thesis on 10 November 2023
“Engineering of the interlayer space of nanolaminate membranes for molecular sieving”
Front of the jury composed with:
– Sophie CASSAIGNON, Professeure, Sorbonne Université – Rapportrice
– Mohamed El-ROZ, Chargé de recherche, University of Caen Normandy – Rapporteur
– Cecilia DE CARVALHO CASTRO E SILVA, Associate Professor, Mackenzie Presbyterian University – Examinatrice
– Benoit MAHLER, Chargé de recherche, Université Claude Bernard Lyon 1 – Examinateur
– Philippe MIELE, Professeur, Université de Montpellier – Directeur de thèse
– Damien VOIRY, Chargé de recherche, Université de Montpellier – Co-Directeur de thèse
Abstract:
This thesis presents an in-depth exploration of the potential and challenges of two-dimensional (2D) material membranes for various separation applications, offering both foundational insights and innovative approaches to their design and application. It begins by investigating the rise of 2D material membranes, notably graphene oxide (GO), transition metal dichalcogenides (TMDs), and transitional metal carbides and/or nitrides (MXene), as a promising alternative to conventional polymer membranes for diverse separation applications. Meanwhile, the challenges faced by 2D membranes are also addressed. In the end, the tailoring strategies for 2D materials to enhance their membrane separation performance are highlighted.
The thesis then delves into the development of laminar membranes constructed from 2D MoS2 nanosheets, demonstrating the manipulation of interlayer space for enhanced desalination performance. We reveal a strategy to fine-tune the capillary widths and stacking structure of the nanochannels depending on the nature of the functional groups attached to the MoS2 nanosheets, leading to impressive water permeation and salt rejection rates. This work paves the way for the future design of energy-efficient desalination and nanofiltration membranes.
Lastly, the focus shifts to organic solvent nanofiltration (OSN) applications of 2D laminated clay membranes. By intercalating mono and multivalent cations, particularly Fe3+, into the interlayer of clay nanosheets, we significantly enhance the stability and molecular sieving ability of the membranes, demonstrating impressive performance in dye separation and organic solvent purification.
Future research perspectives are also explored, highlighting the importance of enhancing membrane stability, scalability, and developing sustainable fabrication techniques. The prospects for further investigating the roles of functional groups and cations in modifying membrane properties, developing larger-scale nanolaminated membranes, and exploiting the full potential of 2D laminated clay membranes for OSN are discussed. This thesis not only offers valuable insights into the current state and potential of 2D material membranes but also sets a strong foundation for future research in the field.
