Abstract
We present a facile method to enhance separation performance of polyamide (PA) reverse osmosis (RO) membranes via solvent activation with a new type of organic solvent, benzyl alcohol (BA). Activation with BA remarkably improved water permeance (up to ∼140% increase) while maintaining high NaCl rejection (∼99.6%) of the pristine RO membrane, thereby overcoming the flux-rejection trade-off limitation. Thus, the water permeance and permselectivity of the BA-activated RO membrane significantly exceeded those of commercial RO membranes. This significant performance enhancement was attributed to the appropriate solvency power of BA (determined based on Hansen solubility parameters), which led to the balanced structural deformation of the PA selective layer; BA activation produced a less dense and highly permeable PA structure by greatly swelling PA, while simultaneously healing loosened sites via structural compaction of the PA network with a sufficiently reduced modulus. Based on the activation results with various organic solvents ranging from mild to strong solvents, we propose a more reliable predictor of the solvent activation effect. Our strategy is a simple, effective and commercially viable method to enhance RO membrane performance. Additionally, our study highlights on the underlying solvent activating mechanism of PA RO membranes.
Original language | English |
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Pages (from-to) | 220-229 |
Number of pages | 10 |
Journal | Journal of Membrane Science |
Volume | 578 |
DOIs | |
Publication status | Published - 2019 May 15 |
Bibliographical note
Funding Information:This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (NRF-2018R1A4A1022194), Korean Ministry of Environment as “Global Top Project (2016002100007)” and a Korea University Future Research Grant.
Funding Information:
This research was supported by the National Research Foundation of Korea ( NRF ) grant funded by the Korean government ( MSIP ) (NRF- 2018R1A4A1022194 ), Korean Ministry of Environment as “Global Top Project ( 2016002100007 )” and a Korea University Future Research Grant.
Keywords
- Benzyl alcohol
- Interfacial polymerization
- Polyamide thin film composite membrane
- Reverse osmosis
- Solvent activation
ASJC Scopus subject areas
- Biochemistry
- General Materials Science
- Physical and Theoretical Chemistry
- Filtration and Separation