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[Display omitted] • The interfacial polymerization is regulated by the inverse diffusible organic phase additive polypyrrole nanoparticles (PPYN). • The modified reverse osmosis (RO) separation layer features abundant free volume. • The flux of the modified RO membrane increases nearly 3 times compared with the pristine RO membrane without sacrificing separation selectivity. • The modified RO membrane exhibits excellent anti-biofouling property. Highly permeable thin film composite (TFC) reverse osmosis (RO) membranes with abundant free volume are desirable for water treatment. However, the strategy of controlling the microstructure of the separation layer with high free volume rate is still a challenge. In this work, a modified strategy for the preparation of high-performance TFC RO membrane with inverse diffusible polypyrrole nanoparticles (PPYN) as organic phase additive was developed. The combination of PPYN and trimesoyl chloride (TMC) would diffuse backwards from the organic phase into the aqueous phase during the reaction process to disrupt the normal interfacial polymerization (IP) and thus introduce more free volume in the RO membrane due to the nanobubbles from violent reactions. Moreover, the thickness of the modified membrane decreased and the hydrophilicity increased based on the modulation of IP by PPYN, which facilitated the water molecules to transport. The prepared RO-PPYN membranes showed nearly three times the flux compared with the pristine RO membrane without sacrificing separation selectivity. Furthermore, the anti-biofouling property of the modified membrane was also improved. This work successfully demonstrated the potential use of PPYN as an organic filler to enhance the performance of seawater desalination in RO membranes. Our modification strategy provides an efficient and convenient way to prepare novel RO membranes with high permeability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Monomers developed in recent years for preparation of TFC membranes is summarized. • The relationship between monomer structure and membrane properties is established. • The application problems of the IP monomers are summarized. • The outlook for future development of the monomer is also discussed. The thin-film composite (TFC) membranes fabricated by interfacial polymerization (IP) can be applied in the fields of nanofiltration (NF) and reverse osmosis (RO), which has the unparalleled advantages, such as high selectivity and permeability, small capital investment and low energy consumption, thus attracting great research interest in industry and academia field. The performance of TFC membranes is determined by their microstructure and physicochemical properties while IP monomer plays a decisive role regarding both. Over the past few decades, the researchers have paid intensive and sustained efforts to develop new IP monomers. This paper reviews these monomers and the corresponding membranes developed in recent years with the aim of establishing an intrinsic relationship between monomer structure and membrane properties. The excellent performances based on new monomers in enhancing the permeability, selectivity, anti-fouling and chemical stability of NF and RO membranes for liquid treatment are highlighted. Finally, various problems in the monomer development are summarized and the outlook for future development is also discussed. [ABSTRACT FROM AUTHOR]

• Thin graphene quantum dots interlayer-based polyarylate membranes were prepared by interfacial polymerization. • The influence of two kinds of graphene quantum dots towards membrane structure was discussed in detail. • The quantum dots partially or fully released from the interlayer further optimized the intrinsic properties of the separation layer. • The polyarylate membranes showed excellent CO 2 /N 2 separation performance. Interlayered-thin film nanocomposite (i-TFN) membranes with nanomaterials as the interlayer has attracted more and more attention of researchers in recent years due to the effective regulation of the separation layer structure in the membrane separation field. In this work, the amino-functionalized graphene quantum dots (N-GQDs) were synthesized and applied as an interlayer to modify the polyethersulfone (PES) ultrafiltration substrate. Then interfacial polymerization (IP) between trimesoyl chloride (TMC) and β-cyclodextrin (β-CD) was performed to prepare novel i-TFN polyarylate membranes for CO 2 /N 2 separation. The effect of the N-GQDs deposition amount on the structure and gas separation performance of the composite membrane was studied thoroughly. The results indicated that the i-TFN polyarylate membrane presented a particular sandwich structure and provided an effective transport channel for the diffusion of CO 2. Moreover, the affinity of the N-containing groups (e. g. amino and amide groups) in the i-TFN membrane and the CO 2 molecules helped to increase the CO 2 /N 2 separation selectivity. At the optimal preparation condition, the obtained i-TFN membrane showed CO 2 /N 2 selectivity of 23.3 with CO 2 permeance of 174.5 GPU. This work proposes a novel nanomaterial interlayer to effectively improve the gas permselectivity by regulating the structure of i-TFN membranes, which has significant instruction for the preparation of high-performance i-TFN by exploring the interlayer of other nanomaterials. [ABSTRACT FROM AUTHOR]

• Novel polyarylate NF membranes were prepared with oligomeric phenolic resin monomer. • NF membrane exhibited a high Na 2 SO 4 rejection rate and excellent chlorine-resistance. • The influence of preparation parameters on the NF membrane performance was investigated. Conventional water treatment polyamide nanofiltration (NF) membranes often suffer from the degradation of sodium hypochlorite (NaOCl) in sewage or during the process of membrane cleaning and deteriorate the separation performance, which significantly increases the treatment cost. Herein, a novel polyacrylate composite NF membranes were prepared by interfacial polymerization using oligomeric phenolic resin (OPR) and trimesoyl chloride (TMC) as aqueous and organic phase monomer respectively on the polyethersulfone (PES) ultrafiltration supporting membranes. The fabrication parameters, including the pH of the aqueous solution, reaction time and the concentration of the monomer, on the performance of the composite NF membranes were optimized. A series of characterization indicated that the surface of the NF membranes was negatively charged, the molecular weight cut-off (MWCO) and the pore diameter of the polyacrylate membrane were 400 Da and 0.47 nm, respectively. At the optimized preparation conditions, the NF membrane exhibited high Na 2 SO 4 rejection of 98.2% and water flux of 2.42L·m−2·h−1·bar−1, which was superior to most of the polyacrylate NF membranes reported in recent years. Compared with the polyamide membrane, the prepared polyacrylate membrane demonstrated better chlorine-resistant property and still maintained 92.0% Na 2 SO 4 rejection after being treated with NaOCl solution. Moreover, the NF membrane preserved excellent long-term operation stability. The chlorine-resistant NF membrane constructed from OPR monomer has a broad application prospect in the field of high chlorine wastewater treatment. [ABSTRACT FROM AUTHOR]

• Special circular microporous polyarylate membrane was prepared by interfacial polymerization. • Three kinds of CD (α-, β- and γ-CD) presented different polycondensation reactivity. • The types and content of alkali in the aqueous solution affected the membrane structure and gas permeation properties. • β-CD/TMC polyacrylate membranes showed high CO 2 /N 2 separation performance. Microporous polymer membranes have received extensive attention in the membrane separation field based on the advantage of high gas permeance and low cost. However, there are a few reports of microporous polyacrylate membranes fabricated by interfacial polymerization (IP), and the formation mechanism and influence factor of the microporous structure is rarely illuminated. In this work, thin-film polyacrylate membrane with circular microporous morphology were prepared by IP method with cyclodextrin and acyl chloride as the aqueous and oil phase monomer respectively for effective gas separation. The effects of the aqueous and organic phase monomer structure and concentration, the concentration and type of alkali in the aqueous solution on the membrane morphology and gas separation performance were investigated in detail. As a result, the polyacrylate membrane fabricated by β-cyclodextrin (β-CD) and trimesoyl chloride (TMC) with optimal content of NaOH in the aqueous phase formed the special circular microporous structure by the scanning electronic microscope (SEM) characterization. The resulting membrane showed CO 2 permeance of 200 GPU with CO 2 /N 2 ideal separation selectivity of 10.53. This work provides an effective strategy to fabricate high performance polyacrylate membrane by regulating the monomer structure and the alkali concentration in the aqueous phenol solution with IP method, which would inspire the exploration of other phenolic monomer for the assembly of microporous polymer membranes for gas separation or seawater desalination. [ABSTRACT FROM AUTHOR]