Ultrathin polyamide membranes enabled by spin-coating assisted interfacial polymerization for high-flux nanofiltration

Bai

et al. 2023

Environ. Sci. Technol.

Improving the nanofiltration (NF) performance of membrane-based treatment is conducive to promoting environmental water recycling and addressing water resource depletion. Combinations of light, electricity, and heat with traditional techniques of preparing membranes should optimize membrane performance. Interfacial polymerization and photopolymerization were integrated to construct a photopolymerized thin-film composite NF membrane with a ridged surface morphology. Under visible light initiation, 2-acrylamido-2-methyl-1-propanesulfonic acid was crosslinked with the polyamide network. The control effects of light on the membrane surface and physicochemical properties were revealed via infrared thermal images and response surface methodology. To present the diffusion motion of piperazine molecules, molecular dynamics simulations were implemented. Through density functional theory simulations, the crosslinking mechanism of the photoinduced NF network was identified and verified. The surface physicochemical characteristics and perm-selectivity performance were systematically illustrated. The photopolymerized membrane outperformed the pristine in permeability and selective separation competence; without degradation of solute repulsion, the water permeation was enhanced to 33.5 L m–2 h–1 bar–1, 6.6 times that of the initial membrane. In addition, the removal of organic contaminants and antifouling capacities were improved. This work represents a novel lead for applying sustainable resources in constructing high-performance membranes for environmental challenges.

Section: Resultsmentioning

confidence: 93%

Section: Materials Andmentioning

confidence: 95%

Employing Visible Light To Construct Photoinitiated Polymerized Nanofiltration Membranes for High Permeation and Environmental Micropollutant Removal

Bai

et al. 2023

Environ. Sci. Technol.

“…On the one hand, the excess solution in the substrate pores will further increase the thickness of the polyamine film and lead to the blocking of the micropores of the substrate, 68,76 which will make the controllability of the polymerization worse 77 and result in a reduction in water flux. 78 At the same time, it will also cause a large amount of solvents and monomers to be wasted. Hence efforts were made to reduce the amount of solvents and monomers and improve the controllability of the polymerization reaction.…”

Section: Constructing Interfaces By Unconventional Methodsmentioning

confidence: 99%

Interfacial polymerization at unconventional interfaces: an emerging strategy to tailor thin-film composite membranes

Xin,

Fan,

Guo

et al. 2023

Chem. Commun.

“…Actually, NF membranes based on PIP and TMC always exhibit outstanding desalination performance in terms of rejection and water permeance. [ 35–37 ] However, in the IP process of PIP and TMC, the reaction between the acyl chloride group and amine group is fast, but the diffusion of PIP and TMC into the reaction zone from both phases is slow. [ 38–41 ] Meanwhile, the trans‐interface diffusion rate of PIP across the water/oil interface is much slower than that of TMC in hexane solution.…”

Section: Introductionmentioning

confidence: 99%

“…Actually, NF membranes based on PIP and TMC always exhibit outstanding desalination performance in terms of rejection and water permeance. [35][36][37] However, in the IP process of PIP and TMC, the reaction between Positively charged nanofiltration (NF) membranes with high perm-selectivity are highly desired to remove divalent cations such as Ca 2+ and Mg 2+ ions to ensure the safety of domestic and industrial water supply. In this work, a poly(piperazinamide) NF membrane with a positively charged surface is fabricated via the surfactant-assembly regulated interfacial polymerization (SARIP) of piperazine (PIP) and 1,3,5-trimesoyl chloride (TMC).…”

mentioning

confidence: 99%

Positively Charged Poly(Piperazinamide) Nanofiltration Membranes for the Fast Removal of Metal Ions

Liu

Kong

Bian

et al. 2022

Adv Materials Inter

In addition, in daily life and industry, the high mineral content in water will cause scaling and serious plumbing failures in boilers and heat exchangers, reducing the service efficiency of these appliances. [9][10][11] High-efficient ion separation technology to remove the divalent cations is necessary to deal with these problems. [12][13][14] Due to the characteristics of selective separation of monovalent/divalent or multivalent ions, nanofiltration (NF) separation technology stands out in the application of seawater desalination, food processing, printing, dyeing textiles, and other fields. [15][16][17][18][19] The mechanism of the NF membrane for ions separation depends on the synergistic effect of electrostatic repulsion and size sieving. [15,20] Positively charged NF membranes generally provide a higher rejection for removing divalent/multivalent cations from water. [21,22] The conventional interfacial polymerization process is usually based on the monomer structure, using m-phenylenediamine (MPD) and poly ethylene imine (PEI) as water monomers to prepare normal positivecharge nanofiltration membranes. [23,24] For instance, the famous commercial NF membrane, NF90, is prepared from MPD and 1,3,5-trimesoyl chloride (TMC), which has an excellent retention effect on metal cations (including mono valent ions). [15,24,25] However, the IP reaction activity of MPD and TMC is too high to control, and it is easy to form a dense active layer, producing low permeance and non-selective removal of monovalent and divalent ions. [25][26][27] Due to the large molecular weight and slow diffusion, the positive NF membranes derived from PEI always suffer from the problem of low regulation of the reaction process, loose pore structure, and thick active layer, leading to relatively low rejection of divalent metal ions and water permeance. [28][29][30][31][32] Till now, piperazine (PIP) has been the most commonly used aliphatic amine monomer in the preparation of polyamide (PA) NF membranes. [18,33,34] Compared with other amine monomers, PIP is a small molecule with a definite molecular size. The polymeric network structure obtained from the interfacial polymerization of PIP and TMC could be designed by tuning the chemical equivalent ratio of PIP and TMC participating in the reaction in theory. Actually, NF membranes based on PIP and TMC always exhibit outstanding desalination performance in terms of rejection and water permeance. [35][36][37] However, in the IP process of PIP and TMC, the reaction between Positively charged nanofiltration (NF) membranes with high perm-selectivity are highly desired to remove divalent cations such as Ca 2+ and Mg 2+ ions to ensure the safety of domestic and industrial water supply. In this work, a poly(piperazinamide) NF membrane with a positively charged surface is fabricated via the surfactant-assembly regulated interfacial polymerization (SARIP) of piperazine (PIP) and 1,3,5-trimesoyl chloride (TMC). The surfactant assembly can accelerate PIP monomer into the hexane to react with TMC monomer...