Fabrication of novel buckypaper metal oxide nano-catalysis glycerol carbonate/MWCNTs membrane for efficient removal of heavy metals.

This study describes the fabrication of novel buckypaper membranes through the dispersion of multi-walled carbon nanotubes (MWCNTs) in the presence of surfactants metal oxide nano-catalysis Zinc oxide and magnesium oxide (ZnO and MgO) glycerol carbonate separately. Following vacuum filtration of the scattered solutions, self-supporting membranes known as buckypapers (BPs) were produced. The suggested membranes were employed for the efficient removal of heavy metals. The obtained data indicated that the incorporation of both glycerol carbonates prepared by two different nano metal oxides enhanced the permeability of MWCNTs membranes rejection efficiency. The characterization of the synthesized metal oxide nanoparticles, as well as the physicochemical and morphological properties of the membranes, were investigated. The rejection capabilities of membranes for the heavy metal ions were examined. Moreover, the suggested MWCNTs/ZnO nano-catalyst glycerol carbonate BP membrane displayed high rejection efficiency for heavy metals (Cd2+, Cu2+, Co2+, Ni2+, and Pb2+) than that prepared from the MgO nano-catalyst one.

Unfunctionalized and Functionalized Multiwalled Carbon Nanotubes/Polyamide Nanocomposites as Selective-Layer Polysulfone Membranes.

Nowadays, reverse osmosis is the most widely utilized strategy in membrane technology due to its continuous improvement. Recent studies have highlighted the importance of the surface characteristics of support layers in thin-film membranes to improve their reverse osmosis performance. In this study, interfacial polymerization was used to generate the membranes by employing polyamide as a selective layer on top of the polysulfone supporting sheet. Different membranes, varying in terms of the concentrations of unfunctionalized and functionalized multiwalled carbon nanotubes (MWCNTs), as well as ethanol, have been fabricated. The efficiency of the membrane has been increased by increasing its permeability towards water with high salt rejection. Different characterization techniques were applied to examine all of the fabricated membranes. PA-EtOH 30% (v/v), as a selective layer on polysulfone sheets to enhance the membrane's salt rejection, was shown to be the most efficient of the suggested membranes, improving the membrane's salt rejection. The water permeability of the polyamide membrane with EtOH 30% (v/v) was 56.18 L/m2 h bar, which was more than twice the average permeability of the polyamide membrane (23.63 L/m2 h bar). The salt rejection was also improved (from 97.73% for NaCl to 99.29% and from 97.39% for MgSO4 to 99.62% in the same condition). The PA-MWCNTs 0.15% membrane, on the other hand, had a reduced surface roughness, higher hydrophobicity, and higher water contact angle readings, according to SEM. These characteristics led to the lowest salt rejection, resulting from the hydrophobic nature of MWCNTs.

Preparation and Characterization of Modified Polysulfone with Crosslinked Chitosan-Glutaraldehyde MWCNT Nanofiltration Membranes, and Evaluation of Their Capability for Salt Rejection.

Nanofiltration membranes were successfully created using multi-walled carbon nanotubes (MWCNTs) and MWCNTs modified with amine (MWCNT-NH2) and carboxylic groups (MWCNT-COOH). Chitosan (CHIT) and chitosan−glutaraldehyde (CHIT-G) were utilized as dispersants. Sonication, SEM, and contact angle were used to characterize the as-prepared membranes. The results revealed that the type of multi-walled carbon nanotubes (MWCNT, MWCNT-COOH and MWCNT-NH2) used as the top layer had a significant impact on membrane characteristics. The lowest contact angle was 38.6 ± 8.5 for the chitosan-G/MWCNT-COOH membrane. The surface morphology of membranes changed when carbon with carboxylic or amine groups was introduced. In addition, water permeability was greater for CHIT-G/MWCNT-COOH and CHIT-G/MWCNT-NH2 membranes. The CHIT-G/MWCNT-COOH membrane had the highest water permeability (5.64 ± 0.27 L m−2 h−1 bar−1). The findings also revealed that for all membranes, the rejection of inorganic salts was in the order R(NaCl) > R(MgSO4).