CRYSTENGCOMM
·
2017
·Vol. 19
·期 30
·4345-4354
·
IF 3.474
Meng Liu,Chuming Yin,Peng Chen,Mingtao Zhang,Sean Parkin,Panpan Zhou,Tonglei Li,Faquan Yu,Sihui Long
Chlorine can participate in numerous interactions such as halogen bonding, hydrogen bonding, and London dispersion in the solid state. In this work, we report the influence of a chlorine substituent on the polymorphism of a potential anticancer drug, 4-chloro-phenylanthranilic acid (CPAA). Three polymorphs have been discovered for this compound, and the three forms were characterized by single-crystal X-ray diffraction, power X-ray diffraction (PXRD), FT-IR, and Raman spectroscopy. Both conformational flexibility of the molecule and the sp2CH⋯Cl hydrogen bond seem to lead to the polymorphism of the system. The phase behavior was investigated by differential scanning calorimetry (DSC), with the conclusion that form II converts to III upon heating. A conformational scan shows the conformational minima corresponds to the conformers existing in the polymorphs. Lattice energy calculations show energies of −106.70, −104.72, and −194.42 kJ mol−1 for forms I to III, providing information on relative stability for each form. Hirshfeld analysis revealed that intermolecular interactions such as H⋯H, C⋯H, H⋯Cl, and H⋯O contribute to the stability of the crystal forms.
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Analytical Methods
·
2016
·Vol. 8
·期 10
·2226-2232
·
IF 1.915
Linye Jiang,Haijian Liu,Ming Li,Yue Xing,Xueqin Ren
We tested a simple and economical approach to synthesize CdTe quantum dots (QDs). We then developed a MIP-capped CdTe QD fluorescent sensor by anchoring a molecularly imprinted polymer (MIP) layer on the surface of CdTe QDs using 3-aminopropyltriethoxysilane as the functional monomer and tetramethoxysilane as the cross-linker via a surface molecular imprinting process. The sensor possessed the sensitivity of CdTe QDs, the selectivity of the molecular imprinting technique, and a nearly spherical morphology. The fluorescence of the MIP-capped CdTe QDs can be efficiently quenched when the template 4-nitrophenol (4-NP) rebinds to the binding sites, as a result of the charge transfer from QDs (donor) to 4-NP (acceptor). MIP-capped CdTe QDs generated a significantly reduced fluorescence intensity within the initial 12 min of binding 4-NP. Under optimized conditions, the sensor presented a satisfactory linearity with 4-NP concentrations in the range of 1–30 μM, and the detection limit was 40 nM. The sensor also successfully detected trace amounts of 4-NP in water samples, and the recovery of 4-NP in three spiked samples ranged from 95.1% to 98.1% with relative standard deviations below 4.3%. The results provide an alternative method for the development of sensors for the rapid recognition and determination of 4-NP in water samples.
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ENERGY & FUELS
·
2017
·
IF 3.091
Xiaocai Meng,Jianying Wang,Haichao Jiang,Xinle Shi,Yongqi Hu
A functional 2-ethyl-4-methylimidazole alanine ([Emim][Ala]) ionic liquid was synthesized. Its density, viscosity, and surface tension were measured at the temperature range from 293.15 to 343.15 K at atmosphere pressure. The solubility of SO2 in pure [Emim][Ala] ionic liquid and the binary mixture of [Emim][Ala] and water was also investigated. The absorption\desorption mechanism of SO2 was proposed on the basis of 13C nuclear magnetic resonance and Fourier transform infrared spectroscopy. Results showed that SO2 was captured as ammonia sulfonic acid ester by pure [Emim][Ala], while for the binary mixture of [Emim][Ala] and water, the final product of SO2 absorption is alanine and [Emim]+[HSO3]−/[Emim]+2[SO3]2–.
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RSC Advances
·
2017
·Vol. 7
·期 65
·40705-40710
·
IF 3.108
Ruizhi Pang,Kaisong Zhang
Surface modification is a common approach to improve the desalination performance of polyamide (PA) reverse osmosis (RO) membranes. Nevertheless, the water flux normally decreases due to the additional hydraulic resistance of the surface modification layer. Surface grafted PA RO membrane with 4-(2-hydroxyethyl)morpholine was first fabricated to improve water flux in this study. 4-(2-Hydroxyethyl)morpholine was in situ grafted onto the nascent PA membrane by the reaction between the –OH group of 4-(2-hydroxyethyl)morpholine and the unreacted –COCl groups of the nascent PA membrane and residual trimesoyl chloride. The surface grafted RO membranes were characterized by X-ray photoelectron spectrometry, field emission scanning electron microscopy, atomic force microscopy and contact angle measurement. The surface grafting conditions, including 4-(2-hydroxyethyl)morpholine dipping time, heat treatment time, and 4-(2-hydroxyethyl)morpholine concentration, were optimized by characterizing the desalination performance under brackish water desalination conditions. The resulting surface grafted membrane exhibited a water flux of 125.71 L m−2 h−1 and a salt rejection of 98.6%. The surface grafted membrane surpassed the control polyamide membrane with 41.9% increase in the water flux. Our results demonstrated that surface modification by in situ grafting 4-(2-hydroxyethyl)morpholine is a promising approach to fabricate high-flux RO membranes.
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EUROPEAN JOURNAL OF PHARMACOLOGY
·
2024
·
IF 4.2
Wenyuan Yu,Jianghuiwen Lu,Xinqi Huang,Huiru Zhuang,Yumei An,Mingyang Zhang
Background Effective drugs for preventing or treating skin flap necrosis remain elusive. In this study, we investigated the potential protective effect of exendin-4 against skin flap ischemia-reperfusion injury (IRI) through the inhibition of ferroptosis. Method A rat abdomen was constructed with an island skin flap, and the superficial vascular pedicle of the abdominal wall was closed using a vascular clamp, which was removed after 8 h. Before surgery, RSL3 and ferrostatin-1 solutions were intraperitoneally injected. After the surgery, subcutaneous injections of exendin-4 were administered daily. The number of inflammatory cells, mean vascular density, collagen fiber content, and apoptosis and ferroptosis indicators were quantified 24 h after reperfusion. Survival, contraction rate, and blood perfusion of the skin flap were evaluated on days 1, 3, 5, and 7 after reperfusion. Results The flap survival rate was significantly higher in the exendin-4 group than that in the injury group, whereas the contraction rate was lower. Compared with the injury group, the exendin-4 group showed less inflammatory cell infiltration, higher vascular density, and less collagen fiber loss. At the molecular level, the exendin-4 group demonstrated opposite or elevated expression of apoptosis and ferroptosis indicators than those in the injury group, with significantly increased glutathione peroxidase 4 (Gpx4). Ferroptosis inhibitors and agonists enhanced and reversed the protective effects of exendin-4, respectively. Conclusion Exendin-4 alleviates skin flap IRI by upregulating Gpx4 expression to inhibit ferroptosis. Therefore, exendin-4 may serve as a novel clinical treatment for skin flap IRI.
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PubMed
高影响因子
SYNTHETIC METALS
·
2024
·
IF 4
Hailan Zeng,Ruomei Wu,Yanan Li,Haiyun Jiang,Xiang Wang,Weili Zhang,Ziyu Li,Jun Zhang,Zhengrong Yan
In this work, the copolymers were successfully synthesized by electrochemical polymerization of two monomers, bithiophene (BT) and 3,4-ethylenedioxythiophene (EDOT), in a lithium perchlorate/propylene carbonate (LiClO 4 /PC) solution. The as-prepared were characterized with the aid of cyclic voltammetry, colorimetric analysis, Fourier transform infrared spectroscopy, and Ultraviolet-visible spectroscopy. The electrochromic and colorimetric properties of copolymers poly(2,2′-bithiophene-co-3,4-ethylenedioxythiophene) (P(BT-co-EDOT)) and homopolymer poly(2,2′-bithiophene) (PBT) in 0.1 M LiClO 4 /PC solution were investigated, and the coloring process based on the redox reaction of the film was observed. When an anodic potential is applied, the copolymer P(BT-co-EDOT) films show a color change from blue-purple to blue-gray changes, and the homopolymer PBT shows a color change from orange to brown. In addition, spectroelectrochemistry studies indicate that copolymer P(BT-co-EDOT) has a lower optical band gap (1.73–1.87 eV) than homopolymer PBT. The copolymers P(BT-co-EDOT) show a high optical contrast (36.65–42.62%) and coloration efficiency (215.8–296.6 cm 2 C −1 ). The copolymer P(BT1-co-EDOT1) demonstrates excellent redox cycling stability, with 90% of the original optical contrast maintained after 500 cycles, making it an ideal candidate for copolymers.
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CARBOHYDRATE RESEARCH
·
2018
·
IF 2.074
Wenwei Han,Quancai Li,Youjing Lv,QingChi Wang,Xia Zhao
The sulfation pattern plays a crucial role in chondroitin sulfate (CS) biological activity, and preparation of CS with defined structure is essential for accurate pharmacological study. In this study, we focused on the preparation of regioselective 4- O /6- O -desulfated CS derived from porcine, employing a dimethyl sulfoxide-methanol (DMSO-MeOH) method and an N-methyl-N-(trimethylsilyl) -trifluoroacetamide (MTSTFA) method CS, respectively. Results showed that the sulfate at C4 position (4- O -S) of N-acetylgalactosamine (GalNAc) was selectively removed by the DMSO-MeOH method, and the sulfate at C6 position (6- O -S) of GalNAc was selectively removed by the MTSTFA method. Structures of desulfated CS were characterized by means of FT-IR, NMR and disaccharide composition analysis. The preparations of regioselective 4- O /6- O -desulfated CS are powerful for the study of structure-activity relationship of CS.
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LIQUID CRYSTALS
·
2024
·
IF 2.4
Rui-Zhe Zhou,Yan Zhang,Ji-Feng Gao,Shuai-Yin Ma,Hong-Shuang Zhang,Xiao-Zhi He
By introducing two cholesteric liquid crystal monomers with different chain lengths (M1 and M2) and brominated naphthalimide fluorescent monomer (M3) into polymethyl hydrosiloxane, a series of fluorescent cholesteric liquid crystal polymers (FL-LCP) was prepared, which not only have excellent performance of liquid crystal and fluorescence but also own performance of selective reflection. Their chemical structures were confirmed to be in accord with molecular design by FT-IR and 1 H NMR spectroscopy, and found them with excellent thermal stability, mesomorphic behaviour and thermal performance by TGA, POM, DSC and XRD, and confirmed all the polymers belonged to the cholesteric phase. The FL-CLCPs emitted different intensity fluorescence under UV light, and conclusions about the relationship between fluorescence and temperature had been drawn. A comparative study was conducted on the fluorescence properties of powders and films of monomers and polymers.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2011
·Vol. 124
·期 1
·109-115
·
IF 1.24
Jikui Wang,Guofeng Cai,Xudong Zhu,Xiaping Zhou
The oxidative chemical polymerization of 3, 4-ethylenedioxythiophene (EDOT) was conducted at room temperature in the presence of poly(styrene sulfonate) (PSS) as the doping agent, sodium supersulphate (Na 2 S 2 O 8 ) and ferric sulphate(Fe 2 (SO 4 ) 3 ) as the compound oxidant and deionized water as the solvent. In order to remove sodium ion (Na + ), ferric ion (Fe 3+ ), and sulfate ion (SO4 2− ), certain amount of ion exchanger was added after 24 h, the dark blue poly(3, 4-ethylenedioxythiophene) (PEDT)/PSS solution was obtained. The influence of different proportions of EDOT and PSS, different proportions of EDOT and the compound oxidant, different stirring rates on the morphology, and surface resistivity were discussed. The influence of pH value of the PEDT/PSS solution, the coating thickness, and soak time on the surface resistivity was investigated. Recipe and experimental conditions were optimized and the PEDT/PSS solution was obtained with excellent performance which has relatively low in surface resistance, good water tolerance, and light transmittance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Libo Sun,Qingtai Xie,Heshun Jing,Xueqing Liu,Lijun Zhao,Xun Sun,Baorong Duan,Caixia Qi,Huijuan Su
Here, Au/polydopamine (Au/PDA) catalysts were prepared by gold sol adsorption (Au/PDA(Sol)), PDA in situ reduction (Au/PDA(PDA reduction)) and DA in situ reduction (Au/PDA(DA reduction)). The factors that influence the performance of Au-PDA on the reduction of 4-nitrophenol (4-NP), were systematically studied for the first time. The catalytic performance of Au/PDA(Sol) is the best because of the uniform and small size of Au nanoparticles (NPs) (3.2 ± 0.7 nm), with a turn over frequency (TOF) of 10125 h −1 , a mass-normalized rate constant ( k’ ) of 33360 min -1 g Au -1 and an apparent activation energy (Ea) of 11.39 KJ/mol. It is confirmed that there are electronic interactions between Au and the catechol hydroxyl groups and imino groups of PDA. Some unreduced Au 3+ ions can be reduced in situ by NaBH 4 during the catalytic reaction, forming ultra small Au NPs and leading to a good initial catalytic activity, especially for Au/PDA(DA reduction). This work systematically studied the influencing factors in catalysis for Au/PDA, providing guidance for the preparation and industrial application of PDA supported noble metal catalysts.
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Polymers
·
2025
·Vol. 17
·期 3
·318
·
IF 4.9
Linyi Shui,Xianxin Guo,Jinrong Li,Zimeng Li,Qinghua Zhao,Guohua Chen,Xiaomin Zhao
Long-chain hyperbranched polyesters (LHBPx, x = 1, 2, 3) with varying lengths of branched chains were synthesized through a thiol-ene click reaction. Subsequently, LHBPx was incorporated into PA4 via the solution method to prepare a LHBPx/PA4 polymer blend, aiming to address the limitations of PA4, such as its narrow thermal processing window (△T = Td5−Tm) and high brittleness. The results demonstrated that the addition of LHBPx enhanced the △T of PA4 from 1.6 °C to 14.5 °C (LHBP3/PA4), increasing the rheological properties of LHBPx/PA4 polymer blends, thereby improving its thermal processability. Compared with PA4, the elongation at the break of the LHBP3/PA4 polymer blend was increased by 20.4%, and the brittle fracture was changed into a ductile fracture. The crystallinity of PA4 was greatly decreased, from 54.41% to 37.42%, owing to the incorporation of LHBPx, whereas Tmof PA4 had almost no change. It was explained that LHBPx hindered the crystal growth stage, whereas it promoted the nucleation stage of PA4, resulting in no significant change in crystal type. Moreover, the longer the branched chain of LHBPx was, the more pronounced the improvement in the thermal processability and toughness of PA4 became. Above all, this work was meaningful for the potential application of PA4 in industrial plastics.
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高影响因子
IONICS
·
2024
·
IF 2.4
Yan Qiang,Zhu Wenxu,Ma Xiaoxue,Liu Na,Liu Yucheng,Xia Meichen
A series of ether-functionalized paramagnetic ionic liquids, 1-(2-methoxyethyl)-3-alkylimidazolium tetra thiocyanate cobalt [C n 2O1IM] 2 [Co(NCS) 4 ] ( n = 1, 2, 3), was synthesized and characterized. The density, surface tension, refractive index, and electrical conductivity of these ionic liquids were measured at 293.15 to 343.15 K at intervals of 5 K, and their thermal expansion coefficients α were calculated. The molecular volume was obtained by measuring the pore volume and porosity. Based on Glasser theory, the standard entropy S 0 (298 K), lattice energy U POT , surface entropy S a , and surface enthalpy, H of the ionic liquids were calculated, and the reason why the ionic liquid is in a molten state at room temperature was explained from the perspective of lattice energy. The molar surface Gibbs energy was introduced to improve the traditional Eötvös equation, which was combined with the refractive index to estimate the surface tension, obtaining a fitting index exceeding 0.99. Finally, the relationship between the electrical conductivity of the ionic liquids and temperature was investigated, and the activation energy, molar electrical conductivity, and electrical conductivity diffusion coefficient of the ionic liquids were obtained. The relationship between their properties was summarized. Compared with previously reported ionic liquids using 1-(2-methoxyethyl)-3-methylimidazolium as a cation, this type of ionic liquid has higher density and a smaller coefficient of thermal expansion.
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