Highways for water molecules
Interplay between nanostructure and water vapor transport in block copolymer membranes
- authored by
- Faheem Hassan Akhtar, Hakkim Vovushua, Luis Francisco Villalobos, Rahul Shevate, Mahendra Kumar, Suzana Pereira Nunes, Udo Schwingenschlögl, Klaus Viktor Peinemann
- Abstract
Water vapor removal is a crucial process for several industries (e.g., air conditioning systems, flue gas dehydration, compressed air drying etc.). An effective dehumidification has the potential to drastically reduce the energy consumption and the overall cost of a process stream. Membranes with high water permeance and selectivity are promising candidates to achieve an energy-efficient water removal. We propose self-assembled membranes with interconnected and ordered hydrophilic domains that act as extremely fast water transport highways (water channels). We used a commercial amphiphilic pentablock copolymer (Nexar™), which has the ability to form long-range, self-ordering nanoscale morphologies with rigid end-blocks and a flexible molecular network where polar and non-polar solvents regulated the final morphologies of the membranes. Our results demonstrate how well-defined periodic morphology allow for molecular level control in effective removal of water vapor. The membranes with ordered hydrophilic nanochannels present a 6-fold improvement in water vapor permeability and a 14-fold increase in water vapor/N2 selectivity compared to Nexar™ membranes with disordered domains. Molecular dynamics stimulations are carried out on the self-assembly behavior of block copolymer solution in different solvents. In addition, sorption and desorption kinetics studies for Nexar™ films were correlated to the different morphologies imaged by transmission electron, atomic force and environmental scanning electron microscopy.
- External Organisation(s)
-
King Abdullah University of Science and Technology (KAUST)
- Type
- Article
- Journal
- Journal of membrane science
- Volume
- 572
- Pages
- 641-649
- No. of pages
- 9
- ISSN
- 0376-7388
- Publication date
- 15.02.2019
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Biochemistry, General Materials Science, Physical and Theoretical Chemistry, Filtration and Separation
- Sustainable Development Goals
- SDG 7 - Affordable and Clean Energy
- Electronic version(s)
-
https://doi.org/10.1016/j.memsci.2018.11.050 (Access:
Open)
