The construction of an efficient magnesium-lithium separation thin film composite membrane with dual aqueous-phase monomers (PIP and MPD).

A series of thin film composite (TFC) membranes was prepared with piperazine (PIP) and -phenylenediamine (MPD) in different ratios, and the magnesium-lithium separation performance of TFC membranes in salt-lake brine with the magnesium-lithium ratio of 28 were systematically compared. The prepared TFC membranes exhibited high rejection of magnesium ions and negative rejection of lithium ions with high water flux, enabling high magnesium-lithium separation efficiency. The characterisation using FTIR spectroscopy, XPS, zeta potential measurements, and SEM techniques indicated that the composition and surface morphology of the membrane prepared with dual aqueous monomers were found to be different from those prepared with single aqueous monomers under the similar conditions.

Preparation of a novel zwitterionic striped surface thin-film composite nanofiltration membrane with excellent salt separation performance and antifouling property.

Thin-film composite (TFC) nanofiltration (NF) membranes were fabricated the co-deposition of taurine, tannic acid (TA), and polyethyleneimine (PEI), followed by subsequent interfacial polymerization with trimesoyl chloride (TMC) on the surface of the polysulfone ultrafiltration substrates. The surface properties, including the roughness, hydrophilicity, surface potential, and NF performances were facilely tuned by varying the taurine content for the prepared TFC membranes. In addition, the as-prepared TFC NF membranes had an excellent antifouling property and flux recovery ratio (FRR) in humic acid (HA), bovine serum albumin (BSA) and sodium alginate (SA) filtration tests.

Preparation and characterization of a novel nanofiltration membrane with chlorine-tolerant property and good separation performance.

High water flux, good separation property and excellent chlorine resistance are crucial factors affecting the development of nanofiltration (NF) membranes. To obtain these properties, NF membranes were fabricated interfacial polymerization using -xylylenediamine (-XDA) and polyethyleneimine (PEI) as aqueous monomers. By controlling the concentration ratio of -XDA and PEI in the aqueous solution, it was found that the addition of PEI to the aqueous solution can increase the rejection of the NF membrane to magnesium chloride (MgCl) and magnesium sulfate (MgSO) from 18.