JOURNAL OF MEMBRANE SCIENCE
·
2013
·
IF 4.093
Xue-San Wang,Quan-Fu An,Qiang Zhao,Kueir-Rarn Lee,Jin-Wen Qian,Cong-Jie Gao
Solution-processable polyelectrolyte complexes (PECs) incorporated with both sulfate (OSO3) groups and carboxylic acid groups (COOH) were prepared from sulfated sodium carboxymethyl cellulose (SCMC) and poly(diallydimethylammonium chloride) (PDDA). Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were utilized to characterize the chemical structures of SCMC and the compositions of SCMC/PDDA PECs. Membranes were made from PECs (SPECMs), and their surface properties were studied by field emission scanning electron microscopy and contact angle characterizations. Moreover, SPECMs were subjected to pervaporation dehydration of aqueous ethanol solution. Effects of SPECMs’ chemical compositions and operation conditions on pervaporation performance were studied and discussed in terms of membrane structures. It was found that OSO 3 groups were incorporated into SPECMs in the form of sulfate–amine ion-pairs, and they improved both the selectivity and flux in the dehydration of aqueous ethanol solution. For instance, the flux and water content in permeate for SPECM-0.34 in dehydration of 10 wt% water–ethanol mixture at 70 °C were 1760 g m −2 h −1 and 98.7 wt%, respectively, both of which were much higher than those for pristine PEC membranes with no sulfate groups. Moreover, the high separation performance of SPECMs was stable and both the tensile strength and elongation at break increased with increasing strong ion-pairs content. For instance, the SPECM-0.34 tensile strength and elongation at break were 64.5 MPa and 9.33%.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Mengping Liu,Ling Zhu,Xiaoxian Zhang,Wenhui Han,Yuping Qiu
The association of the cation and anion of ionic liquids (ILs) dominates the absorbability of ILs by activated carbon (AC). Nevertheless, the mechanism behind the role of ion-pairs is largely unknown. In this study, the adsorption of a series of imidazolium derivative-based ILs by AC was involved in response to the octanol-water partition coefficient ( K OW ), hydrogen bonding acidity ( α ), ion-pair binding constants ( K IP ), binding energy of ion-pairs ( E binding ) and density functional theory (DFT) calculation of ILs. A significant positive correlation between lg K OW and K d and between K IP and lg K OW was observed ( p < 0.05). However, both E binding and α was inversely proportional to K IP . Hence, the substitution of oxygen-containing functional groups, such as carboxyethyl, 1-methoxyethyl, and 1-(ethoxycarbonyl)methyl, on imidazolium ring enhanced the hydrogen bond interaction with water molecules and then weakened the binding of imidazolium cation and [NTf 2 ] − , thereby reducing the adsorption of ILs to AC. DFT calculation further revealed that the polar substitution improved the electron density and electronegativity of imidazolium skeleton. By contrast, the ILs functionalized with non-polar groups (e.g., butyl, allyl , and benzyl) generally displayed high K IP values and low α values. Consequently, the formation of hydrogen bond between the oxygen-containing functional groups of IL cation and water would facilitate the dissociation of IL ion-pairs and then decrease the adsorption of ILs on AC.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2022
·Vol. 43
·期 15
·2200170
·
IF 5.006
Chenxiang Ai,Juntao Tang,Qingqing Zhang,Xincun Tang,Shaofei Wu,Chunyue Pan,Guipeng Yu,Jiayin Yuan
Although considerable efforts have been devoted to novel ionic porous networks (IPNs), the development of them in a scalable manner to tackle the issues in pollutant treatment by adsorption remains an imminent challenge. Herein, inspired by natural spider webs, a knitting copolymerization strategy is proposed to construct analogue triazolium salt-based porous networks (IPN-CSUs). It is not only convenient to incorporate the cationic motifs into the network, but easy to control over the contents of ionic pairs. The as-prepared IPN-CSUs displays a high surface area of 924 m 2 g −1 , a large pore volume of 1.27 cm 3 g −1 and abundant ionic sites, thereby exhibiting fast adsorption rate and high adsorption capacity towards organic and inorganic pollutants. The kinetics and thermodynamics study reveal that the adsorption followed a pseudo-second-order kinetic model and Langmuir isotherm model correspondingly. Specifically, the maximum adsorption capacity of the IPN-CSUs is as high as 1.82 mg mg − 1 for permanganate ions and up to 0.54 mg mg −1 for methyl orange, which stands out among the previously reported porous adsorbents so far. It is expected that the strategy reported herein can be extended to the development of other potential efficient adsorbents in water purifications.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Yue Li,Li Wei,Wen Zhang,Zhiqiang Dong,Yuping Qiu
Sorption of ionic liquids (ILs) to soil and porous materials as affected by anions was observed, but scarce effort has been focused on addressing the role of counteranions in sorption and the associated underlying mechanisms. In this work, two series of 1-butyl-3-methylimidazolium- (Bmim-) and N -butyl, methyl-benzimidazolium-based (Bmbim-based) ILs coupled with different counteranions were prepared to investigate the effect of anions on IL sorption by soot. The octanol–water partition coefficient ( K ow ) and the ion-pair formation constant at infinite dilution in water ( K IP ° ) of ILs were independently measured to explore the contribution of counteranion-dependent hydrophobicity and ion-pair. A wide range of sorption coefficients ( K d ) of ILs were achieved with values varying from 59.8 to 344.3 L·kg −1 for Bmbim-based ILs and from 253.4 to 489.7 L kg −1 for Bmbim-based ILs. Compared with other anions, bis(trifluoromethanesulphonyl)imide ([Tf 2 N] – ) and hexafluorophosphate ([PF 6 ] − ) exhibit tighter association with IL cations in aqueous solution due to their larger K ow and higher K IP ° . Positive linear relationships between log K IP ° and K d and between log K ow and K d evidenced that the counteranion-dependent sorption of ILs relies on the association strengths of IL cations and counteranions, which further influence the hydrophobicity/hydrophilicity of ion pairs. Compared with that of strongly coordinating anions (such as [CH 3 SO 3 ] − , [CF 3 COO] − , [BF 4 ] − , [CF 3 SO 3 ] − , and [Cl] − ), the addition of weakly coordinating anions (such as [Tf 2 N] – and [PF 6 ] – ) in solution contributes to markedly large sorption enhancement of ILs. Consequently, the contribution of different counteranions on IL sorption is essentially based on the formation of ion pair with different K IP ° and K ow in aqueous solution.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANICA CHIMICA ACTA
·
2021
·
IF 2.545
Yiwen Yao,Feifei Xing,Shourong Zhu
The [2 + 2] condensation between 1,8-dihydroxyanthraquinone diester and 1,3-diamino-2-propanol in ethanol affords pseudocalixarene macrocyclic L2 in high yield. Heating L2 to 200 °C in DMSO can generate much smaller [1 + 1] macrocycle L1 . Crystal structure of L1 shows that all non-hydrogen atoms are coplanar except one carbon from 1,3-diamino-2-propanol. L1 is quite inert, but L2 can interact with alkaline, alkaline-earth, as well as Zn 2+ , Cu 2+ , Fe 3+ and Al 3+ cation (chloride) evidenced by their CV and 1 H NMR. With a L2 :M (1:2), there are discernable UV–vis spectrum/ 1 H NMR changes in the presence Cu 2+ , Fe 3+ , Al 3+ . Anion plays a key role in the cation binding process as the chromogenic response to Li + , Na + , K + , Ba 2+ and TBA + hydroxide. L2 forms 1:1 complex with TBAOH and 2:3 complex with NaOH, KOH, Ba(OH) 2 in DMSO. L2 reacts with LiOH in 1:4 stoichiometric and is one of the highest lithium loading ligand. The reaction is second-order with t 1/2 ~ 30 min for 0.25 mM L2 in the presence of 4.0 eq. LiOH. Besides hydroxide, L2 can interact with TBAF to form 1:1 host–guest complexes evidenced by their color and NMR change. With bulky cation, TBAOH shifts E p(II) more negative, while other cations shift E p(II) to positive. L2 is an ion pair acceptor that binds hydroxide and fluoride salt chromogenic.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACTA MATERIALIA
·
2014
·
IF 3.94
D. Xu,W.L. Li,L.D. Wang,W. Wang,W.P. Cao,W.D. Fei
The high piezoelectric properties of piezoelectric ceramics are typically obtained by inducing a phase transition between two ferroelectric phases, using either the morphotropic phase boundary (MPB) or the polymorphic phase transition (PPT). Here we demonstrate that neither the MPB nor the PPT is necessary to achieve high piezoelectric properties. Our results show that the optimized distribution of Li + –Al 3+ pairs parallel to the [0 0 1] direction, as found in our x LiAlSiO 4 /BaTiO 3 ( x LAS/BT) lead-free piezoelectric ceramic system prepared from ordinary raw materials by conventional solid-state reaction sintering , can generate a large piezoelectric constant ( d 33 ) of 378 pC/N when x = 7.5 mol.%. The d 33 value of the 7.5 mol.% LAS/BT ceramic is more than three times that of the pure BT ceramic. The distortion connected to the proposed Li + –Al 3+ pairs locally creates unit cells of less than tetragonal symmetry, and these low-symmetry cells can be responsible for the high piezoelectric response. The high-temperature stability testing reveals that these doped ceramics are usable at temperatures as high as 120 °C. This piezoelectric mechanism coming from the doping ionic pairs provides a new method to achieve large piezoelectric properties in a wide range of ABO 3 -type perovskite systems.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Crystallization
·
2020
·Vol. 3
·期 3
·e10125
·
IF 0
Rong Yang,Hongwei Cao,Weilong Chen,Lv Ding,Li Chen,Xin Zhang,Jinchun Li
Polymeric β-nucleating agents (β-NAs) have the advantages of good thermal stability, low toxicity, and relatively superior compatibility with isotactic polypropylene (iPP). However, endowing polymeric β-NAs with high efficiency remains a challenge. Herein, we report a strategy that incorporates ionic monomers into polymeric β-NAs to significantly enhance their nucleation efficiency. Sodium dimethyl 5-sulfonatoisophthalate, an ionic monomer, is introduced into a liquid crystalline polyester NA (PBDPS), and the resulting ionomer is named PBDPSi. The attractive interaction between the ion pairs acts as physical crosslinks and stabilizes the active nucleation center of the ordered benzene rings. Moreover, the ionic monomer modifies the viscosity of the liquid crystalline NA and improves the dispersibility of PBDPSi in the iPP matrix. In addition, it enhances the relative growth rate of β-spherulites of iPP. When 5% sulfonate monomer is introduced into the NA, PBDPSi exhibits the optimal β-nucleation effect, and the maximum value (0.97) of the relative content of β-iPP crystals ( k β ) is obtained. Compared with PBDPS, PBDPSi shows better β-nucleation performance, especially at low concentrations. The incorporation of 0.1 wt% PBDPSi into iPP provides a k β value of 0.41, which is almost four times that obtained with PBDPS.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
INORGANICA CHIMICA ACTA
·
2020
·
IF 2.304
Li Li,Feifei Xing,Shourong Zhu
Two N 3 O 3 macrocyclic compounds with rigid chromogenic 1,8-dihydroxylenanthraquione and flexible diethylenetriamine/dipropenetriamine (L1 and L2), were synthesized and characterized. L1/L2 can interact with alkaline, alkaline-earth, as well as Zn 2+ , Pb 2+ , and Al 3+ chloride/perchloride evidenced by their DPV change and 1 H NMR spectra. Unexpectedly, both L1 and L2 can show chromogenic response to Na + , K + , and TBA + hydroxide (but not LiOH). Large cavity L2 can show chromic response to Ca(OH) 2 and Ba(OH) 2 , but L1 can only respond to Ca(OH) 2 in DMSO. L1 and L2 form 1:1 and 2:1 (Host:Guest) complex respectively with NaCl, NaOH, TBAOH in DMF/DMSO. Both hosts bind smaller Zn 2+ and Al 3+ in 2:1 in DMSO. L2 can form L2·TBAOH greenish yellow complex that gradually transformed to red L2 2 ·TBAOH in two steps in DMSO. Different from other macrocycles, L1 and L2 are ion-pair hosts that recognize cation and OH − via carbonyl groups.
研究领域:
有机化学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Xingyuan Wang,Xiansong Shi,Zhe Zhang,Congcong Yin,Zhipeng Zhang,Yong Wang
Intrinsically charged covalent organic frameworks (COFs) afford specific ionic nanochannels for mass transport, and thus become promising platforms to design membranes with unique selectivity. However, internal electrostatic repulsion and large-pore frameworks cause significant barriers that greatly limit membrane performances. Herein, we report a novel strategy to synchronously crystallize and upgrade cationic COF membranes by ion-pairing design. Ion-paired guest molecules are involved in electric-driven interfacial crystallization to offset the charges of the ionic monomers and host frameworks. This host-guest neutralization promotes the crystallization of compact COF membranes. Lateral dimension and charge nature of guest molecules fundamentally affect the ion-pairing efficiency. Tight encapsulation of the large-sized electronegative molecules effectually narrows the molecular sieving channels, yielding a significant elevation in membrane selectivity. The membrane rejection of organic ions with a size larger than 1.2 nm thus can be improved from below 50 % to above 85 % with a water permeance of ∼10 L m −2 h −1 bar −1 . Prominently, our membranes demonstrate efficient recovery and pH-dependent release of bioactive pharmaceuticals, with a release rate that is 12 times higher in an acidic solution compared to a neutral environment. This work provides an ion-pairing strategy to regulate COF membranes for pharmaceutical industries and beyond.
研究领域:
材料科学
·
化学工程
·
药学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Siyuan Luo,Haiyuan Zou,Renji Zheng,Shimao Deng,Xuezhen Feng,Wenfei Wei,Ranhao Wang,Ze Li,Wei Xu,Lele Duan,Hong Chen
Selective electrochemical reduction of CO 2 /CO to high-valuable C 2+ products is of great importance to alleviate the global warming and energy crisis problems, while the selective production of C 2 is severely limited by the C C coupling pathway on the catalyst interface. Herein, by employing a Cu + /Cu 2+ charge-ordered metal-organic framework (MOF) material (denoted to be Cu4BHT) as a CO electroreduction catalyst, a high acetate selectivity of 50.3% at 0.7 V versus reversible hydrogen electrode (RHE) has been achieved. An in-depth mechanism study reveals that the charge-ordered Cu + /Cu 2+ pair on Cu4BHT interface favors the C O bond activation, C C coupling, and proton-coupled electron transfer dynamics, which results in the selective formation of C 2+ products. This work illustrates the critical role of employing charge-ordered Cu + /Cu 2+ catalytic site pair for C C coupling, which paves the way for designing highly selective catalysts to promote the formation of the C 2 products.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2015
·
IF 4.169
Jian-Jun Zhong,Ningbo Liao,Tian Ding,Xingqian Ye,Dong-Hong Liu
Direct separation of biogenic amines by reversed-phase liquid chromatography (RPLC) is not an easy task because their basic and hydrophilic characteristics can lead to poor retention, column overloading, peak tailing, and hence low efficiency. Rather than routinely resorting to derivatization or using classical hydrophobic ion-pair reagents (IPR), this work proposes a new RPLC method making use of the chaotropic salt KPF 6 as inorganic additive to an acidic acetonitrilic eluent to remedy the difficulties. Amine retention, overload behavior, peak shape, and column efficiency were significantly improved. The use of excess KPF 6 led to a very slight decrease of amine retention. Depending on amine, the dependence of the logarithmic retention factor on the volume percent of acetonitrile could be reasonably linear or quite convex. Coupled with UV detection, the method was applied to trace analysis for six biogenic, aromatic or heterocyclic amines in three types of food after a sample cleanup, as necessary, by ion-pair extraction. The reliability of the whole analysis was demonstrated to be satisfactory. The proposed method outperforms existing methods in that it eliminates the need for long and cumbersome derivatization procedures without losing sensitivity; it also represents a good surrogate for classical ion-pair chromatography (IPC) because of the desirable hydrophilicity of chaotropic salts.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2013
·
IF 4.425
Wanzhen Li,Bin Su
Herein we report the nontrivial effect of counterion size on the electrochemical charging of gold nanoparticle (or called MPC) monolayer films in aqueous electrolyte solutions. The electrochemical charging response was observed with relatively small counterions (e.g., BF 4 − , ClO 4 − and PF 6 − ) but not large ones like bis(trifluoromethylsulfonyl)amide (Tf 2 N − ), tetrakis(pentafluorophenyl)borate (TB − ) or bis(triphenylphosphoranylidene) (BA + ). This effect was explained by the proximity of counterions to the MPC surface, which determines whether the electronic charges on MPCs can be effectively compensated by formation of ion pairs . Only small counterions are permitted to approach the MPC surface by permeating the alkanethiolate layer to achieve a sufficient charge compensation. In contrast, big ions are sterically excluded and thus disfavor the electrochemical charging. This finding helps in further understanding the ion-coupled electrochemical charging mechanism of nanoparticle films.
研究领域:
材料科学
·
电化学
✓ 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）