JOURNAL OF CHEMICAL THERMODYNAMICS
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2019
·
IF 2.29
Daofan Ma,Qing Liu,Chunying Zhu,Huisheng Feng,Youguang Ma
The densities and viscosities of binary solutions of (N-methyldiethanolamine + ethanol), (monoethanolamine + ethanol) and (N-methyldiethanolamine + monoethanolamine) as well as ternary solution of (N-methyldiethanolamine + monoethanolamine + ethanol) were measured at T = 293.15 K, 303.15 K, 313.15 K, 323.15 K. The volumetric and viscometric properties, such as the excess molar volume V E , the partial molar volume V ¯ , the partial molar volume at infinite dilution V ¯ ∞ and the viscosity deviation Δ η , were calculated from the experimental densities and viscosities. The excess molar volumes and viscosity deviations of binary and ternary solutions were correlated by the Redlich-Kister equation and the Cibulka’s equation, respectively. The intermolecular interactions in binary and ternary solutions were analysed.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Guangyuan Zhao,Danxin Hu,Shenghu Zhou,Jian Zhang,Lei Wang
A series of supported highly dispersed CuNi alloy nanocatalysts were fabricated by a coprecipitation method for the N-alkylation of aniline with 2,5-dihydroxymethylfuran under base-free conditions. Various characterizations and catalytic experiments were carried out to systematically investigate the relationship between the catalytic performance and synthetic parameters, such as calcination temperatures, reduction temperatures, and catalyst compositions. The optimized Cu3/17Ni6/17Al8/17O catalysts show good selectivity for the N-alkylation of aniline with 2,5-dihydroxymethylfuran under mild reaction conditions. This work broadens the application of non-noble bimetallic nanocatalysts for N-alkylation reactions and opens new opportunities to synthesize useful HMF derivatives and other valuable biobased chemicals.
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JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A
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2019
·Vol. 107
·期 7
·1532-1540
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IF 3.221
Mingchen Zhou,Fei Xie,Guocang Li,Qiyang Wang,Longxiang Tang,Manqing Yan,Hong Bi
The trinary hydroxyapatite@Fe 3 O 4 @N-doped carbon dots (HA@Fe 3 O 4 @N-CDs) hybrids were prepared by one-pot hydrothermal approach and utilized to detect and remove lead ion from aqueous solution. The structures and morphologies of as-obtained nanorod-like HA@Fe 3 O 4 @N-CDs hybrids were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy measurements. These HA@Fe 3 O 4 @N-CDs hybrids possess good magnetism by magnetic hysteresis test and multi-colored fluorescence by the CLSM measurement. Furthermore, the as-obtained hybrids display excellent biocompatibility by MTT assay. Importantly, the trinary magnetic HA@Fe 3 O 4 @N-CDs hybrids as a green detector and adsorbent of Pb 2+ were investigated. The influence of the different pH, the concentration of heavy metal, and the maximum adsorption capacity on removal efficiency was measured in detail. The maximum Pb 2+ adsorption capacity on HA@Fe 3 O 4 @N-CDs hybrids is 450 mg/g. The kinetic mechanism was a pseudo-second order model, and the isotherm data was fitted well by the Langmuir isotherm and Freundlich model. Hence, the nanorod-like HA@Fe 3 O 4 @N-CDs hybrids could be a multifunctional material with significant potential applications in heavy metal detection and adsorption, bone tissue regeneration, magnetic therapy, and biomedicine. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.
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CELLULOSE
·
2019
·Vol. 26
·期 8
·5033-5049
·
IF 3.917
Chen Yong,Ma Yijia,He Qingkun,Han Qiuxia,Zhang Qiang,Chen Qi
Abstract Cotton cellulose was modified with polysiloxane with dual antimicrobial groups of pyridinium and N -chloramine (N-Cl) to endorse enhanced synergistic biocidal ability. A new compound, 4-oxo- N -(pyridin-4-yl)pentanamide (OPPA), that contains precursors of both pyridinium and N -chloramine was synthesized via amidation of 4-oxopentanoic acid and 4-aminopyridine. The molecules of OPPA were connected to cotton cellulose using poly(methylhydrosiloxane) (PMHS) as linker through hydrosilylation reaction between some Si–H groups of PMHS and hydroxyl groups of cellulose and some other Si–H groups and ketone carbonyl groups of OPPA. The OPPA on cellulose was transformed into its biocidal counterpart after quaternization of the pyridine to pyridinium and chlorination of the amide N–H to N -chloramine. The synthetic procedures and modification results were characterized with Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy. The pyridinium/ N -chloramine polysiloxane layer on cellulose was estimated to be 77 nm by weight and provided powerful and synergistic antibacterial capacities against model species of Escherichia coli and Staphylococcus aureus . The stability of the polysiloxane modifier layer and the rechargeability of lost chlorine were promising under repeated washing, long-term storage, and UV irradiation. The presented pyridinium/ N -chloramine polysiloxane layer showed advantages over many of the current systems containing either cationic salt or N -chloramine due to the synergism. Graphical abstract
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RUSSIAN JOURNAL OF APPLIED CHEMISTRY
·
2019
·Vol. 92
·期 6
·848-856
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IF 0.508
Lv Jie,Fu Luoping,Zeng Bo,Tang Mingjin,Li Jianbo
In this paper, citric acid was used as carbon source, diethylenetriamine and urotropine were used as precursors, and N-doped carbon dots (cdh-CDs) with luminescent properties were synthesized by microwave method. The structure of the sample was analyzed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffractometry (XRD), ultraviolet spectrophotometer (UV), fluorescence spectroscopy, etc., and it was proved that cdh-CDs with an amorphous structure about 4–10 nm in diameter was synthesized. The corrosion inhibition performance of cdh-CDs in 1 M hydrochloric acid was evaluated by static weight loss and electrochemical method. The results showed that cdh-CDs have a good corrosion inhibition performance at 60°C, the inhibition efficiency can reach 81.2% when the dosage is 600 ppm. Electrochemical results showed that cdh-CDs are mixed inhibitors which mainly inhibit cathodes.
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POLYMER INTERNATIONAL
·
2019
·Vol. 68
·期 10
·1673-1680
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IF 2.433
Jiahui Su,Yan Yang,Zhikang Chen,Junyi Zhou,Xiaoxuan Liu,Yanxiong Fang,Yanyan Cui
In this study, frontal photopolymerization was applied to the fabrication of thermosensitive poly( N -isopropylacrylamide) (PNIPAm) hydrogels. The influence of experimental conditions and reactant components on the feature of the polymerization front was investigated. The morphology of the samples indicated the successful preparation of PNIPAm hydrogels. The mechanical properties and thermal stability of the obtained hydrogels are discussed. The results indicated that the performance of the hydrogels is related to their microstructure and the type of crosslinkers. The swelling behavior and drug delivery ability were determined under different temperature conditions. The hydrogels exhibit a classical thermoresponsive behavior, which was also demonstrated by the DSC results. Therefore, frontal photopolymerization can be an alternative method for the preparation of PNIPAm hydrogels under mild conditions. © 2019 Society of Chemical Industry
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Polymer Chemistry
·
2019
·Vol. 10
·期 44
·6021-6030
·
IF 4.76
Linfan Shi,Wenyi Wang,Xiong Fu,Yang Yuan,Bin Zhang,Qiang Huang
Ethylene was introduced into cucurbit[n]urils (CB[n]s, n = 5–7) by molecular encapsulation, for comparison with V-type crystalline starch (V-starch) and α-cyclodextrin (α-CD). The encapsulation capacity of inclusion complexes (ICs) followed the order of CB[5] > V-starch > CB[6] > CB[7] > α-CD. X-ray diffractometry, and 13C solid-state nuclear magnetic resonance and Fourier transform infrared spectroscopy confirmed the presence of ethylene gas in the solid matrices. The controlled release kinetics of the ICs were further studied under different storage temperature (4 and 25 °C) and relative humidity (52.9 and 75.5%) conditions. The Avrami equation was adapted to analyze the controlled release kinetics of ethylene gas, showing a diffusion limited mechanism for CB[n]-ICs under all the storage conditions. The ethylene release rate from CB[n]-ICs was accelerated by increasing ambient temperature, but was not sensitive to relative humidity. CB[5] showed the slowest ethylene release rate among the five solid matrices, up to 700 h under 4 °C storage conditions. Molecular simulation suggested two stable molecular conformations for ethylene molecules within the matrices, i.e., type I, two ethylene molecules in the cavity; and type II, one ethylene molecule in the cavity and the other one outside the cavity. CB[5] and CB[6] had a stable type II molecular conformation of ethylene, whereas CB[7] showed similar stability to type I and type II molecular conformations. For the first time, we demonstrated that CB[n]s (particularly CB[5]) are desirable gas storage and release systems for ethylene. This technology can enable precisely controlled and targeted applications of ethylene for food processing and agricultural applications.
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ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Zhangping Lou,Sheng Zhao,Quan Wang,Hui Wei
N-doping strategy has been explored to enhance the activity of carbon nanozymes because the reconstructed electronic structures in N-doped carbon nanozymes are advantageous for the catalytic process. However, carbon nanozymes with high N content are still difficult to obtain due to the instability of N element under high calcination temperatures. To address this challenge, here we proposed a new N-doping strategy to fabricate highly active and specific peroxidase-like carbon nanozymes by using a high N-containing polymer (i.e., polyethylenimine (PEI)) as the N source and a natural clay mineral (i.e., montmorillonite (MMT)) as a template, respectively. We showed that the assembly of MMT with PEI protected N loss under high calcination temperatures and thus retained more catalytically active N sites. The mechanism study showed that the hydroxyl radical could be the key intermediate involved in the peroxidase-like catalysis. We then used the optimized carbon nanozyme with high and specific peroxidase-like activity (i.e., CP600–6) to detect H2O2, glucose, and ascorbic acid. Moreover, we successfully determined the total antioxidant capacity (TAC) in real samples including four commercial beverages, fresh orange juice, and three kinds of vitamin C tablets. The current study not only provides a new strategy for fabricating peroxidase-like nanozymes but also develops a facile TAC assay for future use in evaluation of antioxidant food quality and oxidative stress in healthcare.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Xin-Yu Huang,Zong-Tao Chi,Jian Liu,Dong-Hua Li,Xiao-Jun Sun,Cong Yan,Yu-Chong Wang,Hao Li,Xue-Dong Wang,Wan-Feng Xie
Heterostructured semiconductor materials, combining the collective advantages of individuals and synergistic properties, have spurred great interest as a new paradigm toward detecting of volatile organic compounds recently. Direct use of NiS as a sensing material is impractical because the structure of NiS is unstable, exhibiting an undesirable sensing performance. Herein, we firstly report its incorporation into an ethanol gas sensor with a conventional n -type sensitive material of In 2 O 3 , and the gas sensing performance of the NiS@In 2 O 3 nanocomposites has been significantly enhanced. Nanofiber-like NiS and In 2 O 3 were fabricated via a synergetic approach of electrospinning and calcination processes. The diameters of crystalline NiS and In 2 O 3 are about 150 nm and 120 nm, respectively. Then, the NiS@In 2 O 3 nanocomposites were prepared via re-calcination of as-prepared NiS and In 2 O 3 nanofibers. The results show that the sensor based on NiS@In 2 O 3 exhibits a detecting limit of as low as 5 ppm and a short response time of 8 s at the optimum temperature of 300 ºC, which outstripped that (13 s) of pristine In 2 O 3 and pure NiS sensors (21 s) for the detection of ethanol gas. The remarkable improvement of sensing performance can be attributed to the p - n heterojunction in multi-component phases of NiS and In 2 O 3 .
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RENEWABLE ENERGY
·
2019
·
IF 5.439
Qing-Lu Song,Yun-Peng Zhao,Fa-Peng Wu,Guo-Sheng Li,Xing Fan,Rui-Yu Wang,Jing-Pei Cao,Xian-Yong Wei
Low aromaticity and a large number of oxygen-bridged bonds among the aromatic structural units of lignin make it possible to obtain chemicals directly. A novel Co/ [email protected] catalyst with high activity towards hydrogenolysis of lignin-derived aryl ethers was synthesized according to the pyrolysis process of a predesigned ZIF-67. According to the results of characterization by powder X-ray diffraction (XRD), N 2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), Co was reduced by the carbonized organic linker of ZIF-67, and N was doped into the carbon skeleton of the catalyst. The effects of holding time, temperature, and initial H 2 pressure on the catalytic performance of Co/ [email protected] were evaluated in the selective hydrogenolysis of benzyl phenyl ether (BPE). BPE was completely converted and the selectivity of monomer reached to 98.2% under optimized reaction conditions. The C alk -O bond in BPE was first dissociated to form toluene and phenol, and then phenol was rapidly hydrogenated to form cyclohexanol. Furthermore, the Co/ [email protected] catalyst shows high activity for hydroprocessing and selective cleavage of other lignin-derived aryl ethers, including phenylethyl phenyl, diphenyl ether, dibenzyl ether, dinaphthalene ether, guaiacol, anisole and veratrole.
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SURFACE & COATINGS TECHNOLOGY
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2019
·
IF 3.192
Wei Ma,Lin Li,Xuehong Ren,Tung-Shi Huang
Several hybrid membranes were prepared by chemical bonding of N-halamine/ZnO nanoparticles onto poly-ε-caprolactone (PCL) using a free radical polymerization strategy. The chlorination process led to the formation of N-Cl bonds. Hybrid membranes were characterized by scanning electron microscope , Fourier transform infrared spectra , X-ray photoelectron spectroscopy, and thermogravimetric analyzer. The membranes showed quick response in killing bacteria and provided complete inactivation of about 6 logs of inoculated S. aureus (ATCC 6538) and E. coli O157:H7 (ATCC 43,895) within 5 min and 10 min of contact time, respectively. The constructed micro-nano structure also exhibited good hydrophobic, air-permeable, and mechanical performances. Moreover, their prominent UV light stability could decrease the loss of chlorine and the biocidal hydantoin moiety and provide potent antibacterial stability. The obtained data strongly encourage the use of the composite membranes for food packaging.
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ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Lei Jiao,Weiqing Xu,Hongye Yan,Yu Wu,Chunrong Liu,Dan Du,Yuehe Lin,Chengzhou Zhu
Recently, in situ detection of hydrogen peroxide (H2O2) generated from live cells have caused tremendous attention, because it is of great significance in the control of multiple biological processes. Herein, Fe–N–C single-atom nanozymes (Fe–N–C SAzymes) with intrinsic peroxidase-like activity were successfully prepared via high-temperature calcination using FeCl2, glucose, and dicyandiamide as precursors. The Fe–N–C SAzymes with FeNx as active sites were similar to natural metalloproteases, which can specifically enhance the peroxidase-like activity rather than oxidase-like activity. Accordingly, owing to the excellent catalytic efficiency of the Fe–N–C SAzymes, colorimetric biosensing of H2O2 in vitro was performed via a typical 3,3′,5,5′-tetramethylbenzidine induced an allochroic reaction, demonstrating the satisfactory specificity and sensitivity. With regard to the practical application, in situ detection of H2O2 generated from the Hela cells by the Fe–N–C SAzymes was also performed, which can expand the applications of the newborn SAzymes.
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