title: 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-NH2) 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.
authors.affiliation: †Graduate School of EEWS (Energy, Environment, Water and Sustainability), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Madhusudhana Rao
authors.initials: MR
authors.lastname: Kotte
authors.affiliation: ‡Department of Applied Chemistry, University of Johannesburg Johannesburg, Republic of South Africa.
authors.forename: Alex T
authors.initials: AT
authors.lastname: Kuvarega
authors.affiliation: †Graduate School of EEWS (Energy, Environment, Water and Sustainability), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Manki
authors.initials: M
authors.lastname: Cho
authors.affiliation: ‡Department of Applied Chemistry, University of Johannesburg Johannesburg, Republic of South Africa.
authors.forename: Bhekie B
authors.initials: BB
authors.lastname: Mamba
authors.affiliation: †Graduate School of EEWS (Energy, Environment, Water and Sustainability), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.|§Environmental Science and Engineering, Division of Engineering and Applied Science, California Institute of Technology Pasadena, California, United States.
authors.forename: Mamadou S
authors.initials: MS
authors.lastname: Diallo
mesh_terms: D000327:Adsorption; D003300:Copper / Q000302:isolation & purification*; D050091:Dendrimers / Q000737:chemistry*; D004777:Environment; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D010539:Permeability; D056951:Photoelectron Spectroscopy; D011145:Polyvinyls / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014462:Ultrafiltration / Q000379:methods*; D014867:Water / Q000737:chemistry*; D005465:Fluorocarbon Polymers
chemical_list: D003300:Copper; D050091:Dendrimers; D008567:Membranes, Artificial; D011145:Polyvinyls; D012996:Solutions; D014867:Water; C104700:PAMAM Starburst; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers