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The effect of altering crosslinker chemistry during interfacial polymerization on the performance of nanofiltration membranes for desalination, organic, and micropollutants removal

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2025-2036 doi: 10.1007/s11705-023-2356-2

摘要： Chemistry of the polyamide active layer of a desalination membrane is critical in determining both its physical and chemical properties. In this study, we designed and fabricated three novel membranes with different active layers using the crosslinkers: terephthaloyl chloride, isophthaloyl chloride, and trimesoyl chloride. The crosslinkers were reacted with an aqueous solution of an aliphatic tetra-amine. Because these crosslinkers differ in their structures and crosslinking mechanisms during interfacial polymerization, the resultant membranes also possess different structural properties. The water contact angle of the fabricated membranes also varies; the water contact angles of 4A-3P-TPC@PSF/PET, 4A-3P-TMC@PSF/PET, and 4A-3P-IPC@PSF/PET, are 68.9°, 65.6°, and 53.9°, respectively. Similarly, the desalination performance of resultant membranes also showed variations, with 4A-3P-TPC@PSF/PET, 4A-3P-IPC@PSF/PET, and 4A-3P-TMC@PSF/PET having a permeate flux of 17.14, 25.70, and 30.90 L·m−2·h−1, respectively, at 2.5 MPa. The 4A-3P-TPC@PSF/PET membrane exhibited extensive crosslinking with aliphatic linear amine, and cationic dye rhodamine B, MgCl2, and amitriptyline rejection rates of 98.6%, 92.7% and 80.9%, respectively. The 4A-3P-TMC@PSF/PET membrane showed mediocre performance, while 4A-3P-IPC@PSF/PET membrane showed even lower performance, with a 35% rejection of methyl orange dye.

关键词： acid chlorides     covalent crosslinking     desalination     linear aliphatic amine     micropollutant removal     thin film composite membranes    

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Cobalt nanoparticle decorated N-doped carbons derived from a cobalt covalent organic framework for oxygen

《化学科学与工程前沿（英文）》 2021年 第15卷 第6期   页码 1550-1560 doi: 10.1007/s11705-021-2104-4

摘要： The low cost and highly efficient construction of electrocatalysts has attracted significant attention owing to the use of clean and sustainable energy technologies. In this work, cobalt nanoparticle decorated N-doped carbons (Co@NC) are synthesized by the pyrolysis of a cobalt covalent organic framework under an inert atmosphere. The Co@NC demonstrates improved electrocatalytic capabilities compared to N-doped carbon without the addition of Co nanoparticles, indicating the important role of cobalt. The well-dispersed active sites (Co-Nx) and the synergistic effect between the carbon matrix and Co nanoparticles greatly enhance the electrocatalytic activity for the oxygen reduction reaction. In addition, the Co content has a significant effect on the catalytic activity. The resulting Co@NC-0.86 exhibits a superb electrocatalytic activity for the oxygen reduction reaction in an alkaline electrolyte in terms of the onset potential (0.90 V), half-wave potential (0.80 V) and the limiting current density (4.84 mA·cm–2), and a high selectivity, as well as a strong methanol tolerance and superior durability, these results are comparable to those of the Pt/C catalyst. Furthermore, the superior bifunctional activity of Co@NC-0.86 was also confirmed in a home-built Zn-air battery, signifying the possibility for application in electrode materials and in current energy conversion and storage devices.

关键词： cobalt embedment     N-doped carbons     covalent organic framework     oxygen reduction     Zn-air battery    

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Reaction and characterization of crosslinking hyperbranched poly (amine-ester) with succine anhydride

XIAO Ling, WEI Xiuzhen, ZHU Baoku

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 355-359 doi: 10.1007/s11705-007-0064-y

摘要： Basing on hydroxyl terminated hyperbranched poly (amine-ester)s (HPAEs), the cross-linking reactions and preparation of ester-crosslinked HPAE films were investigated using succine anhydride (SA) as crosslink reagent. It was proved that the cross-linking reaction between HPAE and SA followed a two-step mechanism. This mechanism provides an efficient route to prepare HPAE/SA cross-linked films, in which, the precursor films were prepared by casting HPAE/SA solution at a lower temperature, and then curing the films at a higher temperature. By varying SA content, the solid HPAE/SA films with different cross-linking degrees were prepared successfully. The highest tensile strength of the cross-linked film could reach 59.60 MPa. With all water contact angle smaller than 74.3°, the crosslinked films demonstrated good hydrophilic properties.

关键词： different cross-linking     amine-ester     temperature     crosslinked     efficient    

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Floret-like Fe–N nanoparticle-embedded porous carbon superstructures from a Fe-covalent triazine polymer

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 525-535 doi: 10.1007/s11705-022-2232-5

摘要： Fe–Nx nanoparticles-embedded porous carbons with a desirable superstructure have attracted immense attention as promising catalysts for electrochemical oxygen reduction reaction. Herein, we employed Fe-coordinated covalent triazine polymer for the fabrication of Fe–Nx nanoparticle-embedded porous carbon nanoflorets (Fe/N@CNFs) employing a hypersaline-confinement-conversion strategy. Presence of tailored N types within the covalent triazine polymer interwork in high proportions contributes to the generation of Fe/N coordination and subsequent Fe–Nx nanoparticles. Owing to the utilization of NaCl crystals, the resultant Fe/N@CNF-800 which was generated by pyrolysis at 800 °C showed nanoflower structure and large specific surface area, which remarkably suppressed the agglomeration of high catalytic active sites. As expect, the Fe/N@CNF-800 exhibited unexpected oxygen reduction reaction catalytic performance with an ultrahigh half-wave potential (0.89 V vs. reversible hydrogen electrode), a dominant 4e– transfer approach and great cycle stability (> 92% after 100000 s). As a demonstration, the Fe/N-PCNF-800-assembled zinc–air battery delivered a high open circuit voltage of 1.51 V, a maximum peak power density of 164 mW·cm–2, as well as eminent rate performance, surpassing those of commercial Pt/C. This contribution offers a valuable avenue to exploit efficient metal nanoparticles-based carbon catalysts towards energy-related electrocatalytic reactions and beyond.

关键词： Fe–Nx nanoparticles     hypersaline-confinement conversion     floret-like carbon     covalent triazine polymers     oxygen reduction reaction    

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Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 548-556 doi: 10.1007/s11705-022-2252-1

摘要： Covalent organic frameworks (COFs) have been increasingly used in capillary electrochromatography due to their excellent characteristics. In this work, hydrazine-linked TFPB-DHzDS (TFPB: 1,3,5-tris(4-formylphenyl)benzene; DHzDS: 2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide) was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material. The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature. After optimizing the coating concentration and experimental conditions of capillary electrochromatography, baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary. And the established method was used successfully to determine PAHs in natural water and soil samples. The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01% to 111.0%, indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples. Finally, molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.

关键词： hydrazine-linked TFPB-DHzDS     in-situ growth method     open-tubular capillary electrochromatography     molecular simulations    

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Preparation of starch esters with crosslinking structures derived from dianhydride

Huijuan CHU, Hongliang WEI, Jing ZHU, Shouyin HU

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 51-54 doi: 10.1007/s11705-010-0534-5

摘要： Starch is a kind of natural polymer used in many industrial fields because of its low cost, availability and biodegradation. Potato starch was modified by esterification with pyromellitic dianhydride, and the products were obtained with crosslinking structures. Orthogonal experiments showed that reactive temperature was the primary influencing factor. The product prepared at 40°C for 3 h with the mass ratio of starch and dianhydride of 16∶1 and pH value of 7.5 exhibited a degree of substitution of 11%. FTIR and UV analysis verified the formation of starch esters.

关键词： potato starch     pyromellitic dianhydride     esterification     crosslink    

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Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 397-404 doi: 10.1007/s11705-019-1884-2

摘要： Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.

关键词： photocatalysis     covalent triazine framework     aqueous medium     SBA-15     solid state    

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DNA alkylation promoted by an electron-rich quinone methide intermediate

Chengyun Huang,Steven E. Rokita

《化学科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 213-221 doi: 10.1007/s11705-015-1541-3

摘要： Biological application of conjugates derived from oligonucleotides and quinone methides have previously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic acids. To enhance the rates of these processes, a new quinone methide precursor with an electron donating substituent has been prepared. Additionally, this substituent has been placed to the nascent -methylene group of the quinone methide for maximum effect. A conjugate made from this precursor and a 5'-aminohexyloligonucleotide accelerates formation of its reversible self-adduct and alkylation of its complementary DNA as predicted from prior model studies.

关键词： quione methide     DNA alkylation     reversible covalent reaction     bioconjugation     target-directed modification of nucleic acids    

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Oil bleed from elastomeric thermal silicone conductive pads

Yuqi Chen,Yakai Feng,Jingqi Zhao,Jingbo Shen,Menghuang Feng

《化学科学与工程前沿（英文）》 2016年 第10卷 第4期   页码 509-516 doi: 10.1007/s11705-016-1586-y

摘要： Oil bleed is a serious problem in elastomeric thermal silicone conductive pads. The components of the oil bleed and the effect of the silicone chemical parameters on the amount of oil bleed have been determined. The main components of oil bleeds are the uncrosslinked silicones in the cured resins, which include the unreacted silicone materials and the macromolecular substances produced by the hydrosilylation reaction. Cured resins with a high crosslinking density and a high molecular weight of vinyl silicone residues had a lower amount of oil bleed. In addition, a low Si-H content also reduced the amount of oil bleed.

关键词： oil bleed     crosslinking density     molecular weight     vinyl silicones     hydrosilicones    

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Dual cross-linked MXene/cellulose nanofiber/nickel alginate film with improved mechanical properties and electromagnetic interference shielding performance

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1460-1469 doi: 10.1007/s11705-023-2335-7

摘要： Electromagnetic interference pollution has raised urgent demand for the development of electromagnetic interference shielding materials. Transition metal carbides (MXenes) with excellent conductivity have shown great potential in electromagnetic interference (EMI) shielding materials, while the poor mechanical strength, flexibility, and structural stability greatly limit their further applications. Here, cellulose nanofibers and sodium alginate are incorporated with MXene nanosheets as flexible matrices to construct strong and flexible mussel-like layered MXene/Cellulose nanofiber/Sodium Alginate composite films, and nickel ions are further introduced to induce metal coordination crosslinking of alginate units. Benefited from the dual-crosslinked network structure of hydrogen bonding and metal coordination, the tensile strength, Young’s modulus, and toughness of the MXene/cellulose nanofiber/nickel alginate composite film are significantly increased. After subsequent reduction by ascorbic acid, excess nickel ions are reduced to nickel nanoparticles and uniformly dispersed within the highly conductive composite film, which further improved its hysteresis loss effect toward the incident electromagnetic waves. Consequently, the MXene/cellulose nanofiber/nickel alginate-Ni composite film presents a considerably enhanced electromagnetic interference shielding effectiveness (47.17 dB) at a very low thickness of 29 μm. This study proposes a feasible dual-crosslinking and subsequent reduction strategy to synergistically enhance the mechanical properties and electromagnetic interference shielding performance of MXene-based composite materials.

关键词： Ti3C2Tx MXene     double crosslinking     mechanical properties     EMI shielding performance    

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Crosslinking acrylamide with EDTA-intercalated layered double hydroxide for enhanced recovery of Cr(VI

Jing Li, Haiqin Yu, Xue Zhang, Rixin Zhu, Liangguo Yan

《环境科学与工程前沿（英文）》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1229-x

摘要： Functional groups of AM and EDTA in composite increased removal of Cr(VI) and CR. Removal process reached equilibrium within 30 min and was minimally affected by pH. Elimination of Cr(VI) was promoted by coexisting CR. Adsorption process of CR was less influenced by the presence of Cr(VI). Mechanisms were electrostatic attraction, surface complexation and anion exchange. We prepared ethylenediaminetetraacetic acid (EDTA)-intercalated MgAl-layered double hydroxide (LDH-EDTA), then grafted acrylamide (AM) to the LDH-EDTA by a cross-linking method to yield a LDH-EDTA-AM composite; we then evaluated its adsorptive ability for Congo red (CR) and hexavalent chromium (Cr(VI)) in single and binary adsorption systems. The adsorption process on LDH-EDTA-AM for CR and Cr(VI) achieved equilibrium quickly, and the removal efficiencies were minimally affected by initial pH. The maximum uptake quantities of CR and Cr(VI) on LDH-EDTA-AM were 632.9 and 48.47 mg/g, respectively. In mixed systems, chromate removal was stimulated by the presence of CR, while the adsorption efficiency of CR was almost not influenced by coexisting Cr(VI). The mechanisms involved electrostatic attraction, surface complexation, and anion exchange for the adsorption of both hazardous pollutants. In the Cr(VI) adsorption process, reduction also took place. The removal efficiencies in real contaminated water were all higher than those in the laboratory solutions.

关键词： Chromate     Dye adsorption     Simultaneous removal     Cross-linking method     Amino functionalization    

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标题 作者 时间 类型 操作

The effect of altering crosslinker chemistry during interfacial polymerization on the performance of nanofiltration membranes for desalination, organic, and micropollutants removal

期刊论文

Cobalt nanoparticle decorated N-doped carbons derived from a cobalt covalent organic framework for oxygen

期刊论文

Reaction and characterization of crosslinking hyperbranched poly (amine-ester) with succine anhydride

XIAO Ling, WEI Xiuzhen, ZHU Baoku

期刊论文

Floret-like Fe–N nanoparticle-embedded porous carbon superstructures from a Fe-covalent triazine polymer

期刊论文

Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for

期刊论文

Preparation of starch esters with crosslinking structures derived from dianhydride

Huijuan CHU, Hongliang WEI, Jing ZHU, Shouyin HU

期刊论文

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

期刊论文

DNA alkylation promoted by an electron-rich quinone methide intermediate

Chengyun Huang,Steven E. Rokita

期刊论文

Oil bleed from elastomeric thermal silicone conductive pads

Yuqi Chen,Yakai Feng,Jingqi Zhao,Jingbo Shen,Menghuang Feng

期刊论文

Dual cross-linked MXene/cellulose nanofiber/nickel alginate film with improved mechanical properties and electromagnetic interference shielding performance

期刊论文

Crosslinking acrylamide with EDTA-intercalated layered double hydroxide for enhanced recovery of Cr(VI

Jing Li, Haiqin Yu, Xue Zhang, Rixin Zhu, Liangguo Yan

期刊论文

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2021年04月22日

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