SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Mengjie Sun,Meng Li,Xu Zhang,Cuiming Wu,Yonghui Wu
Composite anion-exchange membranes with porous structures have been successfully prepared by incorporating quaternized graphene oxide (QGO) into P84 co-polyimide, and then undergoing the phase inversion, amination and quaternization processes. The membranes’ porous structures can be readily adjusted by the category of non-solvent during the phase inversion process. Large finger-like voids are present in the lower parts of the membrane cross sections by using water or 50% isopropanol aqueous solution, which facilitate the entrance of polyethylenimine chains into the membrane matrix, leading to higher degree of amination and quaternization. The incorporation of QGO does not influence the membrane morphology obviously, but can further enhance the ion exchange capacity (1.23–1.65 mmol/g) and decrease the membrane area resistance (1.6–1.9 Ω cm 2 ). The QGO-P84 composite membranes are used in bipolar membrane electrodialysis (BMED) for the removal of boron from synthetic model solutions (Na 2 B 4 O 7 ·10H 2 O, 1000 mg B/L). The finger-like pores decrease the steric resistance of boron transport, while the incorporation of QGO improves the membrane electro-chemical properties and thus the BMED performances. The separation efficiency is 76.6% after running 3 h under 30 V, the current efficiency is 94.9% and the energy consumption is 26.16 kW h/kg by using the optimal composite membrane. The BMED performances are better than those of commercial membrane CJMA-3 (separation efficiency of 51.6%, current efficiency of 81.2%, and energy consumption of 30.56 kWh/kg). Hence, the QGO-P84 composite membranes are effective for removal and recovery of boron from aqueous solution through BMED method.
研究领域:
材料科学
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环境工程
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2018
·
IF 2.795
Mengjie Sun,Meng Li,Pin Wang,Xu Zhang,Cuiming Wu,Yonghui Wu
Anion exchange membranes are prepared by phase inversion of P84 co -polyimide to obtain porous structure, and then chemically modified by branched polyethylenimine. The porous membranes are compared with a dense P84 membrane. The dense membrane is hydrophobic with large area resistance (>85 Ω cm 2 ), while the porous membranes are hydrophilic with low area resistance (2.4–3.5 Ω cm 2 ), lower than that of commercial membrane CJMA-3 (6.0 Ω cm 2 ). The ion exchange capacities are in the range of 0.83–0.86 mmol/g and the water uptake values are 90–130%, both of which are higher than those of dense P84 membrane and CJMA-3 membrane (0.5–0.6 mmol/g; 15–20%). The P84 co -polyimide membranes are utilized in bipolar membrane electrodialysis (BMED) process to produce N -2-hydroxyethylpiperazine- N ′-2-ethanesulfonic acid (HEPES). The porous membranes can decrease the transport resistance of HEPES − ions and yield high recovery ratio and current efficiency, while the dense membrane is unsuitable for BMED . The output of HEPES is increased significantly if the membranes have finger- or tear-like pores, as well as higher ion exchange capacity. The HEPES − recovery ratios are 52.3–61.6% after running 6 h under 40 V, which are higher than that of membrane CJMA-3 (46.5%). The current efficiency can reach up to 86.1% and the energy consumption is only 3.92 kWh/kg by using the optimal porous membrane M-1, which are better than membrane CJMA-3 (65.5%, 5.15 kWh/kg). Hence, the porous membranes have high potential for producing organic acid with high molecular weight.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2018
·Vol. 27
·期 4
·877-883
·
IF 1.712
Runlin Han,Yongli Xie,Xufeng Ma
MXene is a novel 2D lamellar material with excellent hydrophilicity and permselectivity . MXene was introduced in the P84 polymer matrix and the matrix was crosslinked with triethylenetetramine (TETA) to improve the permselectivity and solvent resistance of the polyimide membrane. The membrane was characterized with SEM, AFM and ATR-FTIR, and effects of MXene content on the membrane morphology and separation performance are investigated. The membrane prepared with 18% P84 and 1% MXene shows high rejection (100%) to gentian violet (408) and high flux (268 L·m −2 ·h −1 ) at 0.1 MPa and ambient temperature. MXene endows the membrane with much water channel and denser functional layer which improves the membrane performance obviously. The membrane shows excellent solvent resistance to dimethylformamide (DMF), acetone and methanol after crosslinking with TETA during the 18 days of immersion.
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 94
·期 9
·2838-2843
·
IF 2.587
Runlin Han,Yongli Xie,Xufeng Ma,Da Teng,Shouhai Zhang,Xigao Jian
BACKGROUND Nanofiltration membrane has attracted great study interest because of its high permselectivity and low operating cost. However, most commercial nanofiltration membranes are still not applicable for chemical separation processes due to their low resistance to organic solvent and chlorination. RESULTS 2,4,6-triaminopyrimidine (TAPI) was employed as an aqueous phase monomer to prepare poly (2,4,6-triaminopyrimidine-TMC) composite nanofiltration membrane with interfacial polymerization. Polyimide (P84) ultrafiltration (UF) membrane was crosslinked with TAPI and used as the supporting membrane. The composite membrane showed high rejection (91.4%) of Na 2 SO 4 and a high flux (7.3 L m −2 h −1 ) at 0.3 MPa and ambient temperature. The membrane also showed high stability during 120 h immersion in N,N -dimethylacetamide (DMAc) and acetone. The performance of membrane immersed in 200 ppm NaClO solution did not decline over 96 h. CONCLUSION TAPI with reactive amino group can be used as aqueous phase monomer to prepare poly (2,4,6-triaminopyrimidine-TMC) composite nanofiltration membrane with high permselectivity. The pyrimidine ring of TAPI endows the functional layer with excellent chlorine resistance while the crosslinking of P84 membrane with TAPI significantly improves the solvent resistance. © 2018 Society of Chemical Industry
研究领域:
材料科学
·
膜技术
·
化学工程
·
分离科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Zhen-Yuan Wang,Zheng-Jun Fu,Dan-Dan Shao,Mei-Jin Lu,Qian-Cheng Xia,Hui-Fang Xiao,Bao-Wei Su,Shi-Peng Sun
Delamination of the dual-layer membrane fabricated from immiscible polymers is recognized as the main obstacle to advance the technology. The current work discloses an innovative approach to address the delamination issue by incorporating specific functional groups on the polymer chains. Delamination-free P84®/Ultem® dual-layer hollow fiber nanofiltration membranes were obtained by incorporating 4-Fluoro-2-(trifluoromethyl) benzylamine (FTB) in P84® polyimide . The progressively incorporated FTB on P84® decreases solubility parameter difference and establishes specific intermolecular interactions between the polymer pair which contributes to the interpenetration of molecules at the interfacial region of the dual layers. The interpenetrated network structure at the interfacial region renders the robust integrity of the dual-layer membranes. The one-step fabricated membranes had an over 99% rejection of tetracycline (MW: 444.4 Da) in methanol with pure methanol permeance of 3.7 LMH/bar. The elaborated mechanism may potentially enlarge the scope of selecting immiscible polymers for fabricating dual-layer membranes by molecular designing.
研究领域:
材料科学
·
膜技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）