Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 31
·15245-15252
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IF 9.931
Jing Zhang,Jianhui Fang,Jinlong Han,Tingting Yan,Liyi Shi,Dengsong Zhang
Capacitive deionization (CDI) is a prospective technique for desalination of saline water on account of its lower cost, lower energy-consumption, and absence of secondary pollution. In this work, capacitive deionization of saline water using N, P, S co-doped hollow carbon polyhedra derived from MOF-based core–shell nanocomposites has been demonstrated. N, P, S co-doped hollow carbon polyhedra were rationally designed and originally synthesized from MOF-based core–shell nanocomposites by using poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) coated zeolitic imidazolate framework-8 (denoted as ZIF-8@PZS-C). Choosing poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) as an N, P, S co-doping source and carbon source, and ZIF-8 as a structural template which also acts as an additional N-doping source, ZIF-8@PZS-C was created with a superior hollow structure, high surface area, improved electrical conductivity and an excellent hydrophilic surface. Due to the multi-synergy of these characteristics, the ZIF-8@PZS-C electrodes have lower internal impedance, larger specific capacitance and great cycling stability. What's more, the ZIF-8@PZS-C electrodes display a high salt electrosorption performance of 22.19 mg g−1 at 1.2 V in a NaCl solution of 500 mg L−1. Furthermore, the as-prepared electrodes exhibit good stability and regeneration performance. Hence, the N, P, S co-doped hollow carbon polyhedra should be considered as a promising alternative electrode material for capacitive deionization. This work may open the door for the application of multiple heteroatom co-doped hollow carbon materials for the deionization of saline water.
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ADVANCED POWDER TECHNOLOGY
·
2019
·
IF 3.25
Peng Song,Xiaomei He,Xiaoping Shen,Yiming Sun,Zhiwen Li,Aihua Yuan,Linzhi Zhai,Dongyang Zhang
The rational design and synthesis of porous carbons as supercapacitor electrodes have received tremendous attentions. In this study, a facile all-in-one pyrolysis strategy was developed for producing N and S co-doped porous carbon (NSC), by utilizing cellulose, the most abundant natural reproducible carbohydrate, as precursors. A binary aqueous solution consisting of 9.5% NaOH and 4.5% thiourea served as solvent, porogen and doping reagent, simultaneously. The dissolution and lyophilization procedures allowed a homogeneous mixture, thus achieving a superb activation and doping effects after the pyrolysis. The resultant NSC demonstrated a highly-developed porous texture with a specific surface area of 1588 m 2 g −1 and appropriate heteroatom functionalities with N and S contents of 3.82% and 1.94%, respectively. For three-electrode system, NSC had a high specific capacitance of 288 F g −1 at 0.5 A g −1 in 6 M KOH electrolyte, which was comparable to or even better than many reported cellulose and cellulose derivatives based porous carbon electrodes. The as-assembled NSC//NSC symmetrical cell displayed excellent rate capability and durability, depicting a hopeful candidate for supercapacitors.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Ling Zhang,Sihua Cheng,Lanting Zeng,Fang Dong,Ziyin Yang
1-Phenylethanol is a chiral flavor compound that has enantiomers, ( R )- and ( S )-1-phenylethanol, with different flavor properties. Given that isolating these enantiomers from plants is low yielding and costly, enzymatic synthesis presents an alternative approach. However, the genes/enzymes that specifically produce ( R )- and ( S )-1-phenylethanol in plants are unknown. To identify these enzymes in tea ( Camellia sinensis ) flowers, 21 short chain dehydrogenase (SDR) genes were isolated from tea flowers, cloned, and functionally characterized. Several recombinant SDRs in Escherichia coli exhibited activity for converting acetophenone to ( S )-1-phenylethanol (CsSPESs, >99.0%), while only one SDR produced ( R )-1-phenylethanol (CsRPES, 98.6%). A pair of homologue enzymes (CsSPES and CsRPES) showed a strong preference for NADPH cofactor, with optimal enzymatic reaction conditions of 45–55 °C and pH 8.0. Identification of the tea flower-derived gene responsible for specific synthesis of ( R )- and ( S )-1-phenylethanolsuggests enzymatic synthesis of enantiopure 1-phenylethanol is possible using a plant-derived gene.
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PubMed
高影响因子
POLYMER
·
2018
·
IF 3.483
Jin Han,Cheng Chen,Qingquan Xue,Yaochen Zheng,Shu Tian,Zhixiong Liu,Jieze Shen,Mingqiang Zhong
A catalyst-free and thermal-induced S→O acetyl migration (SOAM) reaction was occasionally found and used to fabricate the polythiol corrosion inhibitor . The route to prepare the polythiols was free of catalyst and side products. Only intramolecular migration process existed, while intermolecular migration was not found. Temperature-dependent 1 H NMR experiment showed the conversion rate of the SOAM reaction was 83% at 160 °C. Further heating at higher temperature or for longer reaction time, the conversion rate did not increase. It was speculated that there was equilibrium between two reversible migrations. The prepared polythiol inhibitor contains a large amount of latent thiol groups after the SOAM reaction process. The strong Cu S bonds immediately formed and made the polythiol chains firmly anchored on the copper surface when the copper metal was coated with the polythiols. Also S S bond formation reaction leads to dense crosslinking and film formation. Raman spectrum and SEM were used to characterized the protective film. A smooth and defect-free film with thickness of 1.9 μm was achieved when the copper sample was immersed in the polythiol solution for 60 min. The corrosion performance of the film is obtained by potential and impedance measurements and Tafel curves by immersing in a 3.5 wt% NaCl solution. All of the coated samples exhibited significantly lower corrosion rates than the bare copper sample, and the corrosion rate decreased as the immersion time increased. The inhibtion efficiency of the polythiol inhibitor was up to 99.3%. Neutral salt spray experiments indicated that the polythiol films provided excellent protection for over one week. The polythiols were also very stable in storage and have application in designing various polyacrylate polythiols resins.
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RSC Advances
·
2014
·Vol. 5
·期 1
·536-544
·
IF 3.708
Baolong Wang,Zhenzhen Cai,Na Zhang,Bin Zhang,Duo Qi,Chengji Zhao,Hui Na
A series of sulfonated naphthalene-based poly (arylene ether ketone)s (SNPAEK-xx) with pendant sulfoalkyl groups were prepared by polycondensation of 1,5-bis(4-fluorobenzoyl)-2,6-dimethoxynaphthalene and o-methylhydroquinone, followed by a demethylation and sulfobutylation reaction. The sulfonate degree of SNPAEK-xx could be controlled easily by adjusting the ratio of 1,4-butane sultone to the hydroxyl content in the demethylated polymers. Flexible and tough membranes with reasonably high mechanical strength were prepared. SNPAEK-xx membranes showed a high ionic exchange capacity (IEC) in the range of 1.13 to 2.27 mequiv. g−1, and the highest proton conductivity of 0.191 S cm−1 at 80 °C. They exhibited low methanol permeability in the range of 1.25–10.22 × 10−7 cm2 s−1, which was much lower than that of Nafion 117. Transmission electron microscopy analysis of SNPAEK-xx revealed that they had a more obvious phase separated structure between the hydrophilic side chain and hydrophobic fully aromatic domains at a higher IEC. Combining their high thermal and mechanical stability, high selectivity, lower water swelling ratio, SNPAEK-xx membranes could be promising materials as alternative to Nafion membranes for direct methanol fuel cell applications.
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JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Yi Zhi Zhuo,Ao Nan Lai,Qiu Gen Zhang,Ai Mei Zhu,Mei Ling Ye,Qing Lin Liu
Anion exchange membrane fuel cells (AEMFCs) have become one of the most promising energy-conversion devices due to the potential of adopting non-noble metal catalysts and faster oxygen reduction reaction kinetics in an alkaline operating environment. Here, a series of anion exchange membranes with high ionic-conductivity and low swelling ratio were prepared from imidazolium-functionalized crosslinked cardo poly(arylene ether sulfone)s for AEMFCs. Two oligomers, tertiary amine-containing poly(arylene ether sulfone) (PES-DA) and bromomethyl-containing poly(arylene ether sulfone) (BPES), are synthesized and then mixed at −40 °C. They are spontaneously inter-crosslinked at room temperature to form dense anion exchange membranes (AEMs), in which the tertiary amine groups of PES-DA rapidly react with the bromomethyl groups of BPES to form the crosslinked bonds. This avoids the use of crosslinking agents and the expense of functional groups. The resulting membranes show a high hydroxide conductivity up to 82.4 mS cm −1 at 80 °C and a slight swelling low to traditional AEMs due to its crosslinked network structure. An open circuit voltage (OCV) of 0.82 V and a maximum power density of 92.1 mW cm −2 are achieved in a H 2 /O 2 single cell. The as-prepared membranes have a great potential for the application in AEMFCs.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Jinchao Li,Yaping Zhang,Shuai Zhang,Xiaodong Huang
We report the fabrication and properties of high performance and inexpensive composite membranes of sulfonated polyimide (SPI) and sulfonated molybdenum disulfide (s-MoS 2 ) for the vanadium redox flow battery (VRFB) application. Scanning electron microscopy (SEM) images reveal the uniformity of SPI/s-MoS 2 membrane. Both EDS and XRD results verify the existence of s-MoS 2 in SPI/s-MoS 2 membrane and show the interaction between SPI and s-MoS 2 . The physico-chemical properties of as-prepared SPI/s-MoS 2 membrane, including water uptake and ion exchange capacity, etc. are evaluated and compared to those of SPI, SPI/MoS 2 and Nafion 117 membranes, respectively. The SPI/s-MoS 2 membrane possesses increased proton conductivity and reduced vanadium ion permeability than pure SPI membrane, and it has the highest proton selectivity (2.24×10 5 S min cm −3 ) among all membranes. The VRFB with SPI/s-MoS 2 membrane presents a higher coulombic efficiency ( CE ) and energy efficiency ( EE ) compared with Nafion 117 at the current density ranging from 20 to 80 mA cm −2 . The SPI/s-MoS 2 membrane shows a longer discharge time (193 h above 0.8 V) than Nafion 117 (72 h). Moreover, the SPI/s-MoS 2 membrane exhibits stable operation performance up to 500 cycles with no significant decline in CE and EE . All experimental results confirm that the SPI/s-MoS 2 membrane is suitable for use in VRFB.
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Advanced Optical Materials
·
2015
·Vol. 3
·期 3
·360-367
·
IF 4.062
Dan Qu,Zaicheng Sun,Min Zheng,Jing Li,Yongqiang Zhang,Guoqiang Zhang,Haifeng Zhao,Xingyuan Liu,Zhigang Xie
A facile solvothermal route to synthesize S,N co-doped graphene quantum dots (S,N-GQDs) with unique optical properties is demonstrated. Three absorption bands are observed at 338, 467, and 557 nm, which is different from any previous reports. The photoluminescent spectra display emissions in three primary colors that are independent of the excitation wavelength, within the excitation wavelength ranges of 340–420 nm, 460–540 nm, and 560–620 nm. The PL excitation spectra indicate that each emission is related to a single excitation band. It is proposed that three independent luminescent centers coexist in S,N-GQDs because the doping with S and N may change the chemical environment of the GQDs. However, energy-transfer processes usually do not occur among the independent luminescent centers under different wavelength light excitation. Heteroatom-doping of GQDs provides an attractive means of effectively tuning their optical properties for the purpose of exploiting new applications in visible-light photocatalytic and bioimaging. S,N-GQDs/TiO 2 composites exhibit better hydrogen production activities under visible light ( λ > 420 nm) than commercial TiO 2 (P25), owing to the presence of characteristic absorption bands in the visible region. Furthermore, the S,N-GQDs have a pronounced biocompatibility and bioimaging ability under long-wavelengths excitation for live A549 cells.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2013
·Vol. 24
·期 9
·807-813
·
IF 1.635
Tao Han,Yi Zhang,Qiaoying Cao,Siwei Liu,Zhenguo Chi,Jiarui Xu
A series of novel optically active poly(ester-imide)s (ter-PEIs) with high glass transition temperature ( T g ), good thermal stability, and solubility were successfully designed and synthesized by direct polycondensation reactions, using p-hydroxybenzoic acid (PHB), 4,4’-dihydroxybenzophenone, and a chiral diacid, N , N '-(pyromellitoyl)-bis-L-phenylalanine diacid as monomers. The resulting terpolymers were characterized by 1 H-NMR, FTIR, element analysis, thermogravimetric analysis, different scanning calorimeter and wide-angle x-ray diffraction, etc. The ter-PEIs are amorphous polymers with good heat resistance and high T g s. They are soluble in many common polar organic solvents and show optically rotation property. The specific rotation values of the ter-PEIs increase with the molar ratio of the chiral diacid, and the rigid PHB monomer is beneficial to increase the T g s of the polymers. Copyright © 2013 John Wiley & Sons, Ltd.
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高影响因子
HIGH PERFORMANCE POLYMERS
·
2016
·
IF 1.045
Lan Li,Jiangtao Liu,Guofei Chen,Lubo Xu,Nafeesa Mushtaq,Lala Rukh Sidra,Ruixin Wang,Xingzhong Fang
A series of cardo poly(ether sulfone imide)s (PESI-C) containing bulky phthalide groups were prepared via aromatic nucleophilic substitution reaction of phenolphthalein with 4,4′-difluorodiphenyl sulfone and 4,4′-bis(4-fluorophthalimido)diphenyl ether (BFPI). The glass transition temperatures and 5% weight loss temperatures in nitrogen of the resulting PESI-C increased from 258°C to 278°C and from 468°C to 495°C with increasing the content of imide moiety in the polymer chain, respectively. These PESI-C films were transparent and essentially colorless and exhibited good mechanical properties with tensile strengths of 91–124 MPa, elongations at break of 6.9–12.8%, and tensile moduli of 2.2–2.8 GPa, respectively. It is noted that the tensile strengths, elongations at break, and tensile moduli of PESI-C also increased with increasing the content of BFPI in the copolymerization, indicating that the properties could be adjusted by controlling the ratio of BFPI and 4,4′-difluorodiphenyl sulfone.
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Polymer Chemistry
·
2016
·Vol. 7
·期 20
·3423-3433
·
IF 5.687
Ke Wang,Zefeng Song,Chonggao Liu,Wangqing Zhang
The thermo- and pH/CO2-responsive poly[N-[2-(dialkylamino)ethyl]acrylamide]s containing a polyacrylamide backbone but different N-substitutes of dialkylamine were synthesized and their solution properties were comparatively checked. A controllable RAFT synthesis of poly[N-[2-(dialkylamino)ethyl]acrylamide]s was achieved when a typical trithiocarbonate containing an easily cleavable R group was employed. The RAFT polymerization rate decreases with the increasing C-number in the N-substitutes. The thermo- and pH/CO2-responsive property of poly[N-[2-(dialkylamino)ethyl]acrylamide]s is firmly correlative to the N-substitutes. With the C-number in the R-substitute increasing, the solution properties of poly(N-[2-(dialkylamino)ethyl]acrylamide)s undergo a soluble-to-thermoresponsive-to-insoluble evolution, and the critical pH of poly[N-[2-(dialkylamino)ethyl]acrylamide]s gradually decreases. The dialkylamine moieties in the poly[N-[2-(dialkylamino)ethyl]acrylamide]s lead to a characteristic CO2-response during CO2/N2 bubbling. The present study reveals the structure-dependent solution properties of the thermo- and pH/CO2-responsive poly[N-[2-(dialkylamino)ethyl]acrylamide]s, and these multistimuli-responsive polymers are believed to be very useful due to the controllable RAFT synthesis and tunable solution properties.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 9
·8976-8984
·
IF 2.76
Guo Huiying,Li Hao,Liang Ni,Chen Fangyuan,Liao Shaohua,Zhang Di,Wu Min,Pan Bo
Bisphenol S (BPS), a new bisphenol analog, is considered to be a potential replacement for bisphenol A (BPA), which has gained concern because of its potentially adverse health impacts. Therefore, studies are needed to investigate the environmental fate and risks of this compound. In this study, the adsorption of BPS and four structural analogs on multi-walled carbon nanotubes (MWCNTs) and graphite (GP) were investigated. When solid-phase concentrations were normalized by the surface areas, oxygen-containing functional groups on the absorbents showed a positive impact on phenol sorption but inhibited the sorption of chemicals with two benzene rings. Among BPS analogs, diphenyl sulfone showed the lowest sorption when hydrophobic effects were ruled out. Chemicals with a butterfly structure, formed between the two benzene rings, showed consistently high sorption on MWCNTs, independent of the substituted electron-donating or accepting functional groups. This study emphasizes the importance of chemical conformation on organic, contaminant sorption on engineered, carbonaceous materials.
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高影响因子
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