JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Chenchen Zhang,Si Chen,Yi Zhao,Jianqiang Meng
Polybenzimidazole (PBI) has garnered significant interest in desalination due to its exceptional chemical stability and mechanical strength , but suffers from poor water permeability. In this work, different contents of hydroxylated Cucurbit [6]uril (CB [6] were added to PBI to build a “water transport channel”. The effects of CB [6] addition on the chemical structure and surface morphology were analyzed by FTIR, SEM, and Zeta potential , respectively. Based on the solution-diffusion model, the effect of CB [6] on the water/salt transport properties of PBI membranes was thoroughly investigated. The results show that appropriate CB [6] doping can enhance water sorption of PBI through the special “outer hydrophilic and inner hydrophobic cavity” structure, and boost water diffusion with the channeling effect of the hydrophobic CB [6] cavity. While the complexation between the carbonyl group in CB [6] and Na + ions slightly increased salt sorption, the specific cavity structure of CB [6] can significantly decrease salt diffusion by blocking salt ions and increasing transport path tortuosity. The cavity effect of CB [6] was further confirmed by hybridizing CB [6] with biphenylsulfonyl-substituted PBI when the cavity can be occupied. Therefore, the introduction of CB [6] improves the water/salt diffusion selectivity and then the permeability selectivity of PBI. Notably, the PBI@CB [6] membrane with a 0.25 wt% CB [6] loading exhibited a 40-fold increase in water permeability coefficient compared to pure PBI, while experiencing only a slight decrease in salt permeability coefficient, water/salt selectivity almost exceeding the empirical upper bound line of polymers. This work provides a theoretical foundation for the development of high-performance desalination membranes based on macrocyclic molecules such as CB [6].
研究领域:
材料科学
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环境工程
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DOI
高影响因子
Journal of Materials Chemistry A
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2019
·Vol. 7
·期 44
·25641-25649
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IF 10.733
Jinqiu Yuan,Mengyuan Wu,Hong Wu,Yanan Liu,Xinda You,Runnan Zhang,Yanlei Su,Hao Yang,Jianliang Shen,Zhongyi Jiang
The demand for thin-film composite nanofiltration membranes bearing unprecedented water permeance and desirable salt rejection is ever increasing in desalination. Conventional interfacial polymerization usually generates a thick (∼100 nm) skin layer on hydrophobic substrate having low-porosity, leading to limited water permeance. Herein, we engineered a highly porous and superhydrophilic composite substrate to modulate the interfacial polymerization and generate an ultrathin polyamide skin layer, even below 10 nm. The composite substrate was constructed by depositing covalent organic framework nanosheets (CONs) on a microfiltration membrane via vacuum-assistant assembly. Owing to the highly porous structure and superhydrophilic nature of CONs, the composite substrate favored a high storage capacity and uniform distribution of the amine monomers. We manipulated the monomer storage capacity of the substrate by varying the loading content of CONs and demonstrated that higher amino monomer concentration could accelerate the self-sealing and self-termination of the interfacial polymerization, thus generating a thinner skin layer from ∼70 nm to sub-10 nm. Moreover, the highly porous structure of CONs imparted little additional water transport resistance. The sub-10 nm film composite membrane exhibited a superior water permeance of 535.5 L m−2 h−1 MPa−1 with a high rejection of 94.3% for Na2SO4, which was about 2–8 times higher than that of state-of-the-art nanofiltration membranes with comparable rejection.
研究领域:
材料科学
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环境工程
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Pengbo Zhao,Junquan Meng,Rui Zhang,Bing Cao,Pei Li
Pervaporation (PV) desalination membranes have good anti-fouling properties due to its hydrophilic dense surface structure. However, organic fouling is inevitable in long-term operation. Sodium hypochlorite (NaClO) is commonly used for cleaning organic pollutant, but it may damage polymeric membrane. Thus, designing membrane material with good chlorine resistance is crucial for expanding its lifespan. In this study, polyvinyl alcohol (PVA) was selected to prepare PV membrane in concern of its hydrophilicity and good film forming property. Its chlorine resistance was improved by removing the more active 1,2-diols of PVA by reacting with sodium periodate, grafting with poly (styrene-co-maleic anhydride) to decrease its crystallinity, and crosslinking using a fluorocarbon surfactant (FS). The resulting PV membrane exhibited the highest reported chlorine resistance of 768000 ppm·h among PV and RO membranes with a high-water flux of 44.5 ± 1.5 kg/m 2 ·h and salt rejection of 99.93%. A long-term fouling and cleaning cycle experiment was carried out using 10000 ppm humic acid to mimic organic foulants. The flux was recovered 100% after the NaClO cleaning. Hence, the chlorine-resistant PV membrane had the ability for sustainable desalination application.
研究领域:
高分子材料科学
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膜分离技术
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环境工程
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水处理
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化学工程
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DOI
高影响因子
MACROMOLECULES
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2025
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IF 5.2
Chenchen Zhang,Jie Liang,Yunfei Yu,Yi Zhao,Shunan Feng,Wenxiong Shi,Jianqiang Meng
High-performance desalination membranes require polymers with optimized free volume and selective transport properties. In this work, the effects of incorporating rigid monomers into zwitterionic poly(arylene ether sulfone) (PAES) membranes on water and salt transport behavior were investigated, grounded in solution-diffusion theory. Three rigid monomers, 9,9-di(4-hydroxyphenyl)fluorene (BHF), 1,1’-binaphthyl-2-phenol (BNP), and 3,6-dihydroxy-9-trifluoromethyl-9-phenylxanthene (3FR), were selected to modify polymer structure. The results demonstrate that the introduction of rigid monomers enhances the free volume and water uptake of the membranes. Notably, the 3FR-based membranes, incorporating both rigid twisted structures and fluorinated groups, exhibited a synergistic effect, significantly improving water diffusion while suppressing salt diffusion. The presence of fluorine atoms in 3FR created stable hydrophobic channels, which not only facilitated rapid water transport but also effectively hindered salt permeation, resulting in superior water/salt selectivity. The study reveals that the combination of rigid and fluorinated structures provides a promising strategy for designing high-performance desalination membranes.
研究领域:
高分子材料
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膜科学与技术
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分离科学
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水处理工程
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功能高分子
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渗透扩散理论
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DOI
高影响因子
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