Enhanced water permeability and osmotic power generation with sulfonate-functionalized porous polymer-incorporated thin film nanocomposite membranes

Abstract

In this study, a hydrophobic porous organic polymer (PP) synthesized via Friedel-Crafts alkylation of dichloro-p-xylene, was functionalized with hydrophilic sulfonate functional group to form PP-SO 3 H, prior to incorporation into the polyamide layer of a hollow fiber pressure retarded osmosis (PRO) TFN membrane. Sulfonate functionalization of the PP material improved the compatibility of the nanomaterial with the aqueous amine precursor during the in situ interfacial polymerization, leading to a decrease in aggregation of the nanoparticles. The effect of nanomaterial loading on the membranes' performance was also elucidated. PP-SO 3 H incorporation resulted in significant improvement of surface hydrophilicity, which along with improved porosity, facilitated enhanced water transport across the membrane and maintained an acceptable salt rejection of the selective layer. The best-performing membrane with PP-SO 3 H loading of 0.002 wt. % showed a 46.3 L m -2 h -1 water flux and power density of 14.6 W m -2 , which are both the highest values recorded. This study suggests that the functionality and chemical properties of the nanomaterial in a TFN membrane is essential in improving altogether the osmotic performance and salinity gradient power harvesting capability during PRO.

Optimal Performance of Thin-Film Composite Nanofiltration-Like Forward Osmosis Membranes Set Off by Changing the Chemical Structure of Diamine Reacted with Trimesoyl Chloride through Interfacial Polymerization

“…As a result of interfacial polymerization reactions between TMC and each of the three diamine monomers (DAPE, CHDA, MPDA), new peaks appeared at 1650 and 1540 cm −1 . These two peaks referred to C=O (amide I) and NH (amide II) of polyamide, respectively [ 29 , 30 ]. MPDA-TMC had a peak at 1612 cm −1 , corresponding to C=C of benzene ring in the structure of MPDA.…”

Facile development of comprehensively fouling-resistant reduced polyketone-based thin film composite forward osmosis membrane for treatment of oily wastewater

“…Thus, in recent, various fabrication methods and membrane modification have been performed to further improve separation performance and fouling resistance. Among these FO membrane modification and fabrication methods include the incorporation of highly porous nano-sized fillers [9,10], hydrophilic coating [11,12], electrolyte deposition [13,14], incorporation of zwitterionic substances [7,15], and chemical grafting and modification [16,17].…”

Developing a Thin Film Composite Membrane with Hydrophilic Sulfonated Substrate on Nonwoven Backing Fabric Support for Forward Osmosis

“…For developing a high-performance membrane, the substrate structure can be modified. There are several options to increase membrane hydrophilicity, such as nanoparticle incorporation in the membrane during phase inversion and/or IP [25][26][27][28][29] and chemical modification [30]. These can be achieved by (a) adding PEG in the support; (b) incorporating Carbone allotropes and other nanoparticles [17,31]; and (c) fabrication methods with "different solvents" and support post-treatment with "activating solvent" [32].…”