Mixed Matrix PVDF Membranes With in Situ Synthesized PAMAM Dendrimer-Like Particles: A New Class of Sorbents for Cu(II) Recovery from Aqueous Solutions by Ultrafiltration
Abstract
Advances in industrial ecology, desalination, and resource recovery have established that industrial wastewater, seawater, and brines are important and largely untapped sources of critical metals and elements. A Grand Challenge in metal recovery from industrial wastewater is to design and synthesize high capacity, recyclable and robust chelating ligands with tunable metal ion selectivity that can be efficiently processed into low-energy separation materials and modules. In our efforts to develop high capacity chelating membranes for metal recovery from impaired water, we report a one-pot method for the preparation of a new family of mixed matrix polyvinylidene fluoride (PVDF) membranes with in situ synthesized poly(amidoamine) [PAMAM] particles. The key feature of our new membrane preparation method is the in situ synthesis of PAMAM dendrimer-like particles in the dope solutions prior to membrane casting using low-generation dendrimers (G0 and G1-NH_2) with terminal primary amine groups as precursors and epichlorohydrin (ECH) as cross-linker. By using a combined thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) casting process, we successfully prepared a new family of asymmetric PVDF ultrafiltration membranes with (i) neutral and hydrophilic surface layers of average pore diameters of 22–45 nm, (ii) high loadings (∼48 wt %) of dendrimer-like PAMAM particles with average diameters of ∼1.3–2.4 μm, and (iii) matrices with sponge-like microstructures characteristics of membranes with strong mechanical integrity. Preliminary experiments show that these new mixed matrix PVDF membranes can serve as high capacity sorbents for Cu(II) recovery from aqueous solutions by ultrafiltration.
Additional Information
© 2015 American Chemical Society. Received: March 29, 2015; Revised: June 29, 2015; Accepted: July 29, 2015; Published: July 29, 2015. This research was carried out at the Korea Advanced Institute of Science and Technology (KAIST) and at the California Institute of Technology (Caltech). The membrane casting, characterization, and filtration experiments were carried out at KAIST. The basic chemistry and methodology used to synthesize the PAMAM particles were developed at Caltech. Funding for KAIST was provided by the National Research Foundation of Korea (NRF) [MEST grant No. 2012M1A2A2026588] and the EEWS Initiative (NT080607C0209721). Funding for Caltech was provided by the National Science Foundation (NSF) [CBET EAGER Award 0948485]. A.T.K. thanks the University of Johannesburg for financial support. The authors declare no competing financial interest.Attached Files
Supplemental Material - es5b01594_si_001.pdf
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Additional details
- Eprint ID
- 60200
- Resolver ID
- CaltechAUTHORS:20150911-142839478
- 2012M1A2A2026588
- National Research Foundation of Korea (NRF)
- NT080607C0209721
- KAIST
- CBET-0948485
- NSF
- University of Johannesburg
- Created
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2015-09-11Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field