SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Zhiwei Zhou,Yaohua Yan,Xing Li,Fanxi Zeng,Senlin Shao
Nanofiltration (NF) is an effective method for removing trace organic compounds (TrOCs) from drinking and reused water. However, chemical cleaning of NF membranes may impact their properties, leading to a decrease in TrOCs rejection. To better understand the mechanisms behind changes in membrane rejection after chemical cleaning, we investigated the changes in surface properties and TrOCs rejection of two commercial membranes (NF270 and NF90) after urea/ hydrochloric acid (HCl) cleaning, and compared them to conventional sodium hydroxide (NaOH)/HCl cleaning. The findings indicated that urea cleaning increased the membrane pore size and hydrophilicity while marginally affecting membrane crosslinking and zeta potential. Possibly due to the thicker and denser active layer of NF90, neither urea-based nor NaOH-based cleaning had a significant impact on its TrOCs rejection and permeability. In contrast, NF270 was more susceptible to chemical cleaning, and urea-based cleaning had less impact on its TrOCs rejection than NaOH-based cleaning. Although urea cleaning increased the pore size of the NF270 membrane, its pore size recovered well after HCl cleaning, resulting in good recovery of the rejection of hydrophilic neutral TrOCs. Moreover, urea cleaning had limited effects on the electrical properties of the NF270 and might enhance the hydrophilicity of the membrane, resulting in full recovery of the rejection of hydrophobic and negatively charged TrOCs after urea/HCl cleaning.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Gao Xuerui,Li Ping,Qin Yuan,Bai Chengling,Gu Zhengyang,Yu Shuili
The negative rejection of certain solutes is an interesting phenomenon often observed in nanofiltration (NF) process, which presents an ideal solute separation effect. In this study, the NF membrane pore size, electric charge property and influent ions composition were controlled to investigate the rule and mechanism of negative rejection phenomenon during SO 4 2− /Cl − mixed salt NF. The results show that the changing of the membrane pore diameter and charge will significantly affect the NF selectivity to SO 4 2− /Cl − , then affect the negative rejection phenomenon. Selective efficiency of Cl − /SO 4 2− can be up to 156.04–283.20 for the negative charged NF membrane with an average pore diameter of 0.62–0.68 nm, and the Cl − was negatively rejected under many influent conditions with the lowest rejection rate of −252.36 %. The substitution of Na + for Mg 2+ and the increase of SO 4 2− /Cl − ratio are beneficial to improve selectivity. The Donnan Steric Pore Model with dielectric exclusion model was used to calculate the rejection curve which is consistent with the experimental results. The analysis of NF mechanism shows that the negative rejection of Cl − is caused by the extra transfer power derived from the NF selectivity to Cl − , which is a compensation for the higher rejection rate of SO 4 2− .
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 18
·11468-11477
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IF 10.733
Mingrui He,Runnan Zhang,Kan Zhang,Yanan Liu,Yanlei Su,Zhongyi Jiang
Reduced graphene oxide aerogels (rGOAs) are broadly applied in energy and environmentally relevant fields. However, rGOAs have been rarely reported for fabrication of separation membranes. In this study, we demonstrate the fabrication of reduced graphene oxide aerogel membranes (rGOAMs) via reduction-induced self-assembly of rGO through hydrogen bond mediation. When using polyethylene glycol (PEG) as the mediator, the PEG–rGO hydrogen bonding interactions partly replace interlayer π–π and hydrophobic interactions during reduction, decreasing the rGO laminates’ size in 2D stacking and alleviating the structural shrinkage of rGOA networks. The tight correlation between membrane pore size and porosity was broken, leading to rGOAMs with tunable pore sizes (0.62 to 0.33 μm) and high porosity (∼95%). The resultant rGOAMs can effectively reject oil-in-water emulsions with different sizes and exhibit ultrahigh water fluxes (up to 4890 L m−2 h−1) under 0.10 bar as well as a persistent anti-oil-fouling performance up to 6 cycles. Three other kinds of hydrophilic polymers including polyvinyl alcohol, polyglycine and polyvinyl pyrrolidone are also utilized as mediators to elucidate the structure–performance relationship. Molecular simulation reveals that the pore size of rGOAMs is strongly affected by the hydrogen bond interaction intensity of the rGO–polymer and polymer size.
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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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
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IF 5.6
Jiawei Zhao,Bo Shang,Cuncai Lin,Xingteng Ma,Yilin Wang,Shenglin Qiao,Xin Sui,Kezheng Chen
The utilization of reverse electrodialysis (RED) technology for efficient conversion of salinity-gradient energy represents a promising strategy for advancing green and low-carbon energy development. The key challenge of RED technology lies in the fabrication of high-performance ion exchange membranes that possess both large surface areas and long-term stability. Silk fibroin (SF), characterized by their abundance of negative charges, ease of processability, and robust mechanical properties, make them particularly suitable for use in energy harvesting through ion permeation. However, a critical limitation in the application of SF membranes is the artificial control of their pore size, which constrains their performance and scalability. Herein, we propose a novel approach for fabricating SF membranes with tunable pore sizes by integrating ionic liquid (IL) with SF. Upon immersion in pure water, the IL dissolve, creating ion transport channels within the membrane. The dimensions of these transport channels can be precisely regulated by adjusting the ratio of IL to SF, thereby enabling control over the membrane’s output power density. Under simulated seawater/river water conditions, the resulting SF membrane demonstrates a stable output power density of 9.6 W/m 2 . This straightforward strategy presents a promising approach for enhancing the efficiency of salinity-gradient energy harvesting.
研究领域:
材料科学
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能源技术
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生物材料
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产品关联
DOI
高影响因子
BIOMEDICAL MICRODEVICES
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2017
·Vol. 19
·期 2
·1-14
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IF 2.062
Zou Lili,Li Shibo,Kang Yufeng,Liu Juanjuan,He Liqun,Sun Sijie,Gao Dayong,Qiu Bensheng,Ding Weiping
In this study, we present a multistage-dialysis microdevice (MDM) for extraction of cryoprotectants (CPAs) from a CPA-laden cell suspension. We confirmed the functions of the key designs of the MDM using a fluorescence solution, we assessed the performance of the MDM by using the MDM to unload glycerin from glycerin-loaded swine erythrocytes, and we investigated the effects of the cell suspension flow rate, glycerin concentration, cell density, and membrane pore size on the clearance efficiency of glycerin (C G ), the survival rate of cells (S C ), and the recovery rate of cells (R C ). Under the designed conditions, C G , S C , and R C reached ~60%, ~90%, and ~70%, respectively. In addition, a high flow rate causes high S C and R C but a low C G . For a low glycerin concentration, C G , S C , and R C are all high. If a low cell density or a large pore membrane is used, C G is high, whereas both S C and R C are low. This work provides insight into the development of microfluidic devices for the inline extraction of cryoprotectants from a small volume of cryopreserved cells prior to the use of the cells in lab-on-a-chip applications.
研究领域:
生物医学工程
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微流控技术
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低温生物学
✓ 已验证
DOI
PubMed
高影响因子
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