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Published on: August 16, 2018
Solvent-Responsive Porous Organic Cage-Based Membranes With Switchable Pore Openings for Molecular Sieving and Heavy
Jisha Kuttiani Ali1,2, Emad Alhseinat1,2
1Department of Chemical Engineering, Khalifa University of Science and Technology, Abu Dhabi, UAE.
Small (Weinheim an Der Bergstrasse, Germany)
|July 25, 2026
Summary
Porous organic cage-based membranes (PCMs) show tunable pore sizes in response to solvents, enabling efficient heavy metal recovery and dye rejection. This solvent-induced pore size modulation offers a novel approach for water purification and resource recovery.
Area of Science:
- Materials Science
- Chemical Engineering
- Environmental Science
Background:
- Porous organic cages (POCs) are advanced materials known for their tunable porosity and film-forming capabilities.
- Their unique structures allow for pore size modulation in response to external stimuli like solvents.
- This responsiveness presents opportunities for novel separation and recovery applications.
Purpose of the Study:
- To demonstrate a solvent-responsive porous organic cage-based membrane (PCM) for heavy metal recovery and molecular sieving.
- To investigate the effect of solvent stimuli on PCM pore size and separation performance.
- To evaluate the efficiency of PCM in rejecting dyes and recovering heavy metal ions from aqueous solutions.
Main Methods:
- Fabrication of PCM-dominated membranes on PTFE supports using specific organic precursors in methanol.
- Characterization of membrane properties and pore size changes using Powder X-ray diffraction (PXRD).
- Performance evaluation through heavy metal ion penetration tests, dye rejection studies, and heavy metal ion recovery experiments.
Main Results:
- PCMs exhibited significantly lower heavy metal ion penetration (~4%) and high dye rejection (94.5%) in water compared to methanol.
- Solvent transition from methanol to water induced a reversible decrease in PCM pore size, confirmed by PXRD.
- Successful recovery of Ni 2+ (52%) and Zn 2+ (45.4%) ions from water was achieved.
Conclusions:
- Solvent-responsive PCMs offer a promising platform for selective separation and recovery processes.
- The ability to tune pore size via solvent stimuli enhances their utility in heavy metal extraction and dye removal.
- This study highlights the potential of PCMs for environmental remediation and resource recovery applications.
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