Polyphenylsulfone-based solvent resistant nanofiltration (SRNF) membrane incorporated with copper-1,3,5-benzenetricarboxylate (Cu-BTC) nanoparticles for methanol separation

Abstract

Mixed matrix membranes (MMMs) of various properties were prepared for a solvent resistant nanofiltration (SRNF) process by incorporating polyphenylsulfone (PPSU) membranes with self-synthesized copper-1,3,5benzenetricarboxylate (Cu-BTC) nanoparticles at different loadings. Cu-BTC nanoparticles were homogeneously dispersed in PPSU dope solution prior to the casting process, and their subsequent presence in the PPSU membrane was inferred by a combination of FTIR spectroscopy, TGA, SEM, EDX and AFM analyses. These analyses confirmed the existence of Cu-BTC particles and their distribution pattern in the membrane matrix. Membrane performance in organic solvent nanofiltration was evaluated on the basis of methanol permeance and dye-methanol separation. Results showed that membrane pure methanol flux was significantly improved from 102 L m À2 h À1 in the pristine PPSU membrane to >135 L m À2 h À1 in the 3 wt% Cu-BTC incorporated into PPSU membrane when both membranes were tested at 14 bar. Apart from preferential channels created by Cu-BTC, the existence of interfacial voids in MMMs also contributes to the flux improvement owing to the formation of alternative paths for solvent transportation. Results also showed that the membranes incorporated with low loadings of Cu-BTC (ranging between 0.5 and 1.0 wt%) tended to have smaller molecular weight cut-off (MWCO) than that of pristine PPSU and PPSU incorporated with 3 wt% nanoparticles, leading to smaller surface pore size but better separation efficiency. The improvement in membrane flux and dye rejection at low Cu-BTC loadings could be attributed to the good dispersion of the nanoparticles in the membrane matrix coupled with their improved interfacial contact with the membrane. The newly developed membrane also showed a great improvement in terms of resistance to compaction, suggesting Cu-BTC particles are of importance in increasing membrane rigidity and strength.

Cu-BTC Metal−Organic Framework Modified Membranes for Landfill Leachate Treatment

“…FTIR analysis was conducted to determine the functional groups in synthesized Cu-BTC. As shown in Figure 1c, the FTIR results are consistent with the results of Cu-BTC reported in the literature [42][43][44]. The wide peak around 3400 cm −1 is ascribed to the stretching vibration of OH, and shows that the Cu-BTC contained water molecules [43].…”

Electrospun metal‐organic framework/polyacrylonitrile composite nanofibrous mat as a microsorbent for the extraction of tetracycline residue in human blood plasma

“…The band at 1443 cm −1 represents the stretching vibrations of carboxylate groups in BTC. The peak at 730 cm −1 can be ascribed to metal Cu substitutions on benzene groups . The peak at 2245 cm −1 (spectrum of PAN) could be attributed to C≡N stretching vibrations.…”

The influence of dispersed phases on polyamide/ZIF-8 nanofiltration membranes for dye removal from water

“…17 The selective micropores of MOFs and the good compatibility between PA and MOFs both led to the great separation performance (enhanced uxes and high rejections) of the PA/MOFs membranes. 34,38 The PA/ZIF-8 membranes showing improved NF performance can be expected. ZIF-8 belongs to a kind of zeolitic imidazolate frameworks materials and has a hydrophobic porous structure with a pore diameter of 0.34 nm.…”

“…20,21 MOFs as membrane materials have attracted great attention for the high porosities, extremely high surface areas, tunable pore sizes, uniform pore structures, and good compatibility between MOFs and polymers. Pure MOFs membranes and polymeric membranes modied by MOFs have been applied in gas separation, [22][23][24][25] pervaporation, [26][27][28] NF, 17,[29][30][31][32][33][34] and RO, 35 exhibiting good membrane performance. MOFs can be idea porous materials embedded in PA for preparing NF TFN membranesdue to the nanoscale particle sizes, identical pore sizes, and network porous structures of MOFs.…”