Soft Matter
·
2018
·Vol. 14
·期 21
·4231-4237
·
IF 3.709
Dahua Li,Yuzhi Xing,Lan Ding,Chengfeng Wu,Guangliang Hou,Bo Song
3-Hydroxyflavone derivatives have great potential as fluorescent probes for bio-labeling in aqueous medium. They were extensively studied in various organic solvents for the “excited state intramolecular proton transfer” process, but seldom addressed in aqueous solution due to the poor water solubility. Herein, an amphiphilic molecule bearing 3-hydroxyflavone and oligo(ethylene oxide) (denoted as 3HF-EO) was designed and synthesized. Different from the fluorescence in organic solvents, 3HF-EO in aqueous solution showed a remarkable single fluorescence emission, which is ascribed to the fluorescence of its anionic species. We found that the fluorescence intensity could be efficiently tuned via host–guest complexation. α-CD has little effect on the emission, while β-CD and γ-CD lead to enhanced and reduced emissions of 3HF-EO, respectively. The 1H NMR and 2D NOESY NMR spectra indicate that α-CD barely had any interaction with 3HF-EO, while β-CD and γ-CD formed complexes with one and two 3HF-EO molecules, respectively. These results provide a sound explanation for the modulated fluorescence intensity.
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TRANSACTIONS OF TIANJIN UNIVERSITY
·
2012
·Vol. 18
·期 5
·315-319
·
IF 0
Feng Yakai,Chen Chengbin,Zhang Li,Tian Hong,Yuan Wenjie
A series of novel copolymers were successfully synthesized by ring-opening polymerization (ROP) of 3(S)-methyl-morpholine-2,5-dione (MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) using stannous octoate as catalyst. The copolymers were characterized by means of 1H-NMR and FT-IR spectroscopy. Gel permeation chromatography (GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry (DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Jinxia Zhou,Tingyu Huang,Yuling Zhao,Zhi Xia,Zhanwei Xu,Songyan Jia,Jianji Wang,Z. Conrad Zhang
Ionic liquids have been widely studied as effective reaction media for the conversion of glucose or cellulose to 5-hydroxymethhylfurfural (5-HMF). However, the recovery of 5-HMF from ionic liquids, typically carried out by extraction, has been encountered with very low extraction efficiency, which limited the reusability of the solvents. Through this work, based on the model biphasic system that consists of 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the ionic liquid phase and methyl isobutyl ketone (MIBK) as the extractant phase, the dominant force that suppresses the extraction efficiency of 5-HMF was identified as being the strong hydrogen bonding between 5-HMF and [BMIM]Cl. Solvent mediation with functional promoters have been established as a new strategy to shift this force, resulting in improved extraction efficiency of 5-HMF from the ionic liquid. For example, with ethanol as a promoter, the distribution coefficient of 5-HMF was about 10 times higher than that without a promoter.
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BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Jingyun Wang,Mingdong Zhou,Yuguo Yuan,Quan Zhang,Xiangchen Fang,Shuliang Zang
Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5 mol% of tetramethyl ammonium perrhenate as catalyst, 70 μL of water, ca. 0.6 mmol of microcrystalline cellulose (MCC) and 2.0 g of [Amim]Cl as solvent under microwave irradiation for 30 min at 150 °C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO 4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose.
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RSC Advances
·
2015
·Vol. 5
·期 22
·16684-16690
·
IF 3.84
Ting Wu,Luyan Wang,Yue Zhang,Sen Du,Wenjuan Guo,Meishan Pei
Poly(3-thiophene acetic acid) (PTAA) nanowires are synthesized in a high yield by electrochemical polymerization, with diameters of about 200 nm and lengths of tens of micrometres. In the reaction systems, the water soluble macromolecules hydroxyethylcellulose (HEC), chitosan (Cs) and polyacrylamide (PAM) are added respectively as templates through a dip-coating process, where the macromolecules are spread on an indium tin oxide glass which is used as the working electrode. However, when polyethylene glycol (PEG) is used, only a PTAA film can be obtained. Therefore the interactions between template macromolecules and TAA monomers play a key role in the formation of PTAA nanowires and the dip-coating process presents an effective way to produce 1D conductive polymer materials with controllable shape. The optical, electrochemical and surface properties are also studied respectively to compare the performances of PTAA film and nanowires, where the latter indicates good electrochemical responsiveness and evidently increased hydrophobicity.
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Chemistry Central Journal
·
2013
·Vol. 7
·期 1
·1-5
·
IF 1.312
Liu Run-Qiang,Bai Lian-yang,Zhang Yi-Jun,Zhang Yu-Ping
Background At present, the study on the homogeneous-phase derivatization of cellulose in ionic liquid is mainly focused on its acetylation. To the best of our knowledge, there has been no such report on the preparation of cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) with ionic liquid 1-allyl-3-methyl-imidazolium chloride (AmimCl) so far.Results With ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction solvent, cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) was synthesized by the reaction of 3,5-dimethylphenyl isocyanate and soluble microcrystalline cellulose in a homogeneous phase. The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP). The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC). Good chiral separation was obtained using n-hexane and different modifiers as the mobile phases under the optimal percentage and column temperature, with the resolution of metalaxyl, diniconazole, flutriafol, paclobutrazol, hexaconazole, myclobutanil and hexythiazox of 1.73, 1.56, 1.26, 1.00, 1.18, 1.14 and 1.51, respectively. The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.Conclusion CDMPC was successfully synthesized as the chiral selector by reacting 3, 5-dimethylphenyl isocyanate with dissolved microcrystalline cellulose in a green ionic liquid of AmimCl.
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RSC Advances
·
2015
·Vol. 5
·期 41
·32416-32420
·
IF 3.84
Kang Qin,Kai Wang,Yang Li,Fanhe Kong,Tao Wang
The phase behavior of the 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and carbon dioxide (CO2) system from atmospheric to supercritical state was investigated at 0.1–15.0 MPa and 308.15–343.15 K. The solubility data of CO2 in [emim][BF4] and the volumetric expansion ratios of CO2-saturated [emim][BF4] were provided. Experimental results indicated that although CO2 dissolved significantly in [emim][BF4] (from 0 to 62 mol%), the ionic liquid phase only had an expansion ratio less than 17 vol%. The density difference between CO2-saturated [emim][BF4] and pure [emim][BF4] was obvious at high pressure and low temperature, with a maximum of 16.11% at 308.15 K and 15.0 MPa. Based on the experimental results, a fitting equation applicable to precise data interpolation was proposed for the CO2-saturated [emim][BF4] density in this study.
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NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 13
·5429-5435
·
IF 3.269
Yongyun Mao,Qian Zhao,Tingting Pan,Jiayan Shi,Shimei Jiang,Meiwan Chen,Bingpu Zhou,Yanqing Tian
Integrating an oxygen-sensitive probe (OSP) onto a three-dimensional (3D) microstructure substrate is a plausible technique to significantly improve the sensitivity of oxygen sensors. Despite the fact that polydimethylsiloxane (PDMS) matrices are regarded as the ideal sensory support, there are still no reports on an OSP functionalized flexible PDMS-based micropillar array (PDMS-MPAs) film as an optical oxygen sensor with capabilities to efficiently improve the sensor's overall performance, e.g. sensitivity, detection limit and stability against photo-bleaching. Herein, we reported the covalent bonding of a functional copolymer of platinum porphyrin (PtTPP)/3-(trimethoxysily)propylmethacrylate (PtTPP/TPMA) as the OSP on the surface of hydroxyl-modified PDMS-MPAs through a “grafting reaction” between PtTPP/TPMA and PDMS-MPAs. The homogeneous dispersion and well-isolated arrangement of the PtTPP/TPMA OSP on the 3D PDMS-MPA surface can ensure that the grafted OSP efficiently quenches the oxygen molecules. Consequently, the 3D PtTPP/TPMA-PDMS-MPA sensor film gives rise to a high fluorescence quenching efficiency of about 95% at 1 atm O2 (I0/I100 = 23) and 96% in aqueous solution (I0/IO2satu = 16) with an excellent linear Stern–Volmer plot (ksv = 0.1 h Pa−1, R2 = 0.997 in gas atmosphere and ksv = 12.8 mmol−1 L, R2 = 0.999 in aqueous solution, respectively), excellent reversibility and an ultra-low detection limit (4.7 μmol L−1) when compared with state-of-the-art PDMS-based oxygen sensors. Apart from the competitive sensitivity, the highly durable, reusable superiorities of the 3D PtTPP/TPMA-PDMS-MPA film can further facilitate the exploration and realization of the presented strategy for future oxygen sensor applications, such as the characterization of nearly anoxic systems in harsh environments.
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RARE METALS
·
2016
·Vol. 41
·期 12
·4273-4278
·
IF 0.957
Huang Shuang,Xu Hua-Lan,Wang Lei,Zhong Sheng-Liang
Rice-like Gd(OH) 3 nanorods were successfully prepared through a facile and rapid microwave-hydrothermal synthesis method without using any surfactants or templates. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy-dispersive spectroscopy (EDS) were used to characterize the samples. Results show that the nanorods have an average length of 400 nm and an average diameter of 50 nm. The effects of reaction parameters such as reaction temperature and time on the preparation were briefly investigated. It is found that the crucial factor for the formation of rice-like Gd(OH) 3 nanorods is reaction time. When the rice-like Gd(OH) 3 nanorods was codoped with Yb 3+ and Er 3+ , strong upconversion emissions could be observed under the excitation of 980-nm-laser, and the calculated CIE color coordinates falls within the yellow region, which may be potential candidate for optical materials.
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Journal of Physical Chemistry C
·
2017
·
IF 4.536
Qing Zheng,Ximing Huang,Yao Liu,Xiaotong Fang,Jie Zhang,Huibo Shao
Quantification of the amount of intermolecular hydrogen bonding between ferrocenemethanol and 3-mercaptopropanoic acid on gold was performed by cyclic voltammetry as well as by the finite element simulation, displaying a proof-of-concept that the slight changes of cyclic voltammetry features are used potentially for interpreting the weak molecular interactions. Ferrocenemethanol at a bulk concentration level of 0.5 mM adsorbs on the 3-mercaptopropanoic acid surface by hydrogen bonding, with the fractional surface coverage ranging from 0% to 14% of a monolayer in accordance with the surface coverage of 3-mercaptopropanoic acid which was explored by electrochemical quartz crystal microbalance. The intermolecular hydrogen bonding between ferrocenemethanol and the mercaptopropanoic acid was found to exhibit a Langmuir-type adsorption with the average value of K being 0.24 mM–1. The intermolecular hydrogen bonding between FcCH2OH and the artificial self-assembled monolayer (3-mercaptopropanoic acid) is evident, and the study on quantification of intermolecular hydrogen bonding with this artificial model is meaningful for understanding the molecular recognition events involved in the cell membrane.
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2017
·
IF 3.454
Anmeng Deng,Laihui Luo,Weiping Li,Feifei Wang,Yaojin Wang
Developing Na 0.5 Bi 0.5 TiO 3 -based magnetoelectric (ME) coupling composites with higher depolarization temperature is highly valuable for the environment-friendly smart electronic devices. We have developed a new kind of 0-3 type 0.94Na 0.5 Bi 0.5 TiO 3 -0.06BaTiO 3 : x CoFe 2 O 4 (NBTBT: x CFO, x = 0, 0.1, 0.2, 0.3) composite ceramics with a deferred depolarization temperature, together with an additional strong ME coupling of 9.2 mV/cm·Oe for the NBTBT:0.2CFO. The basic structure, ferroelectric/ferromagnetic properties, and the depolarization temperature of the NBTBT: x CFO composite ceramics were investigated. It was found that an enhancement of depolarization temperature (>25 °C) was obtained in these 0-3 type composites relative to the pure NBTBT ones (115 °C vs 90 °C). The mechanism of the enhanced depolarization temperature of the composites is discussed. The present results demonstrate that NBTBT: x CFO composites have great potential for ME devices.
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CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Lingjun Bu,Chen Bi,Zhou Shi,Shiqing Zhou
A kind of green tea extract, epigallocatechin-3-gallate (EGCG) was introduced into Fe 2+ activated persulfate (Fe 2+ /PS) system to enhance the degradation efficiency of atrazine. The involvement of EGCG improved atrazine degradation significantly in the pH range of 2.0–7.0, which could be interpreted by the strong reducing and chelating ability of EGCG. EGCG showed a better performance than hydroxylamine and ascorbic acid in modified Fe 2+ /PS systems, as the presence of EGCG could not only accelerate the transformation of Fe 3+ to Fe 2+ , but prevent the formation of iron precipitation. Batch experiments were conducted and atrazine degradation depended upon the dosage of EGCG, persulfate, Fe 2+ , and other water quality parameters including initial pH, co-existing anions and natural organic matters. Radical quenching test and electron paramagnetic resonance (EPR) analysis were also performed and results showed that two kinds of radicals (sulfate radicals and hydroxyl radical) were verified to exist and play a significant role on atrazine degradation in the Fe 2+ /EGCG/PS system. Moreover, possible intermediates of atrazine were identified by HPLC/MS/MS and degradation pathways of atrazine and EGCG were proposed. This study aims to provide a comprehensive understanding on the potential application of EGCG to enhance degradation of refractory organics in water.
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