An ultrahighly permeable-selective nanofiltration membrane mediated by an in situ formed interlayer

2020 ◽  
Vol 8 (10) ◽  
pp. 5275-5283 ◽  
Author(s):  
Yufan Hao ◽  
Quan Li ◽  
Benqiao He ◽  
Bo Liao ◽  
Xianhui Li ◽  
...  
Keyword(s):  
Interfacial Polymerization ◽  
Nanofiltration Membrane

An interlayer is in situ formed to regulate the morphologies and thickness of the polyamide layer during a chitosan assisted interfacial polymerization. The resulted NF membrane exhibits an ultrahigh permeability without compromising on selectivity.

Loose nanofiltration membrane for dye/salt separation through interfacial polymerization with in-situ generated TiO2 nanoparticles

2017 ◽  
Vol 410 ◽  
pp. 494-504 ◽  
Author(s):  
Qi Zhang ◽  
Lin Fan ◽  
Zhen Yang ◽  
Runnan Zhang ◽  
Ya-nan Liu ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Interfacial Polymerization ◽  
Nanofiltration Membrane

scholarly journals Fabrication of High-Performance Thin-Film Composite Nanofiltration Membrane by Dynamic Calcium-Carboxyl Intra-Bridging during Post-Treatment

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 137
Author(s):  
Hongyi Han ◽  
Ruobin Dai ◽  
Zhiwei Wang
Keyword(s):  
Thin Film ◽  
Water Purification ◽  
High Performance ◽  
Rejection Rate ◽  
Post Treatment ◽  
Nanofiltration Membrane ◽  
Film Composite ◽  
Thin Film Composite ◽  
Post Modification

Widespread applications of nanofiltration (NF) and reverse osmosis (RO)-based processes for water purification and desalination call for high-performance thin-film composite (TFC) membranes. In this work, a novel and facile modification method was proposed to fabricate high-performance thin-film composite nanofiltration membrane by introducing Ca2+ in the heat post-treatment. The introduction of Ca2+ induced in situ Ca2+-carboxyl intra-bridging, leading to the embedment of Ca2+ in the polyamide (PA) layer. This post modification enhanced the hydrophilicity and surface charge of NF membranes compared to the pristine membrane. More interestingly, the modified membrane had more nodules and exhibited rougher morphology. Such changes brought by the addition of Ca2+ enabled the significant increase of water permeability (increasing from 17.9 L·m−2·h−1·bar−1 to 29.8 L·m−2·h−1·bar−1) while maintaining a high selectivity (Na2SO4 rejection rate of 98.0%). Furthermore, the intra-bridging between calcium and carboxyl imparted the NF membranes with evident antifouling properties, exhibiting milder permeability decline of 4.2% (compared to 16.7% of NF-control) during filtration of sodium alginate solution. The results highlight the potential of using Ca2+-carboxyl intra-bridging post-treatment to fabricate high-performance TFC membranes for water purification and desalination.

scholarly journals Monitoring the Interfacial Polymerization of Piperazine and Trimesoyl Chloride with Hydrophilic Interlayer or Macromolecular Additive by in-situ FT-IR Spectroscopy

2019 ◽  
Author(s):  
Xi Yang
Keyword(s):  
Ir Spectroscopy ◽  
Reaction Rate ◽  
Interfacial Polymerization ◽  
Reaction System ◽  
Reaction Rates ◽  
Water Permeation ◽  
Ft Ir ◽  
Trimesoyl Chloride ◽  
Ft Ir Spectroscopy

The interfacial polymerization (IP) of piperazine (PIP) and trimesoyl chloride (TMC) has been extensively utilized to synthesize the nanofiltration (NF) membrane. However, it is still a huge challenge to monitor the IP reaction, because of the fast reaction rate and the formed ultra-thin film. Herein, two effective strategies are applied to reduce the IP reaction rate: (1) the introduction of hydrophilic interlayers between the porous substrate and the formed polyamide layer; (2) the addition of macromolecular additives in the aqueous solution of PIP. As a result, in-situ FT-IR spectroscopy was firstly used to monitor the IP reaction of PIP/TMC reaction system, with hydrophilic interlayers or macromolecular additives. Moreover, we study the formed polyamide layer growth on the substrate, in a real-time manner. The in-situ FT-IR experimental results confirm that the IP reaction rates are effectively suppressed and the formed polyamide thickness reduces from 138±24 nm to 46±2 nm. Furthermore, the optimized NF membrane with excellent performance are consequently obtained, which include the boosted water permeation flux about 141~238 (L·m2·h/MPa) and superior salt rejection of Na2SO4 > 98.4%.

scholarly journals Two-dimensional fractal nanocrystals templating for substantial performance enhancement of polyamide nanofiltration membrane

2021 ◽  
Vol 118 (37) ◽  
pp. e2019891118
Author(s):  
Yang Lu ◽  
Ruoyu Wang ◽  
Yuzhang Zhu ◽  
Zhenyi Wang ◽  
Wangxi Fang ◽  
...  
Keyword(s):  
Performance Enhancement ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
Practical Method ◽  
Curing Temperature ◽  
Polymerization Process ◽  
Nanofiltration Membrane ◽  
Two Dimensional ◽  
Fractal Structures ◽  
Templating Method

In this study, we report the emergence of two-dimensional (2D) branching fractal structures (BFS) in the nanoconfinement between the active and the support layer of a thin-film-composite polyamide (TFC-PA) nanofiltration membrane. These BFS are crystal dendrites of NaCl formed when salts are either added to the piperazine solution during the interfacial polymerization process or introduced to the nascently formed TFC-PA membrane before drying. The NaCl dosing concentration and the curing temperature have an impact on the size of the BFS but not on the fractal dimension (∼1.76). The BFS can be removed from the TFC-PA membranes by simply dissolving the crystal dendrites in deionized water, and the resulting TFC-PA membranes have substantially higher water fluxes (three- to fourfold) without compromised solute rejection. The flux enhancement is believed to be attributable to the distributed reduction in physical binding between the PA active layer and the support layer, caused by the exertion of crystallization pressure when the BFS formed. This reduced physical binding leads to an increase in the effective area for water transport, which, in turn, results in higher water flux. The BFS-templating method, which includes the interesting characteristics of 2D crystal dendrites, represents a facile, low-cost, and highly practical method of enhancing the performance of the TFC-PA nanofiltration membrane without having to alter the existing infrastructure of membrane fabrication.

scholarly journals Modification of polyamide TFC nanofiltration membrane for improving separation and antifouling properties

RSC Advances ◽  
2018 ◽  
Vol 8 (27) ◽  
pp. 15102-15110 ◽  
Author(s):  
Li-Fen Liu ◽  
Xiang Huang ◽  
Xiao Zhang ◽  
Ke Li ◽  
Yan-Li Ji ◽  
...  
Keyword(s):  
Interfacial Polymerization ◽  
Aromatic Polyamide ◽  
Good Stability ◽  
Nanofiltration Membrane ◽  
Antifouling Property ◽  
Dye Rejection ◽  
Polymerization Method

TMAAM, a new dendrimer, was used to modify the conventional aromatic polyamide NF membrane via interfacial polymerization method, and the result TMAAM-based semi-aromatic polyamide NF membrane strong dye rejection, favourable antifouling property and good stability.

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