JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Liang Cheng,Pei-Bin Zhang,Yi-Fan Zhao,Li-Ping Zhu,Bao-Ku Zhu,You-Yi Xu
Poly (N-vinyl imidazole) (PVI) gel-filled nanofiltration (NF) membranes were synthesized by UV-initiated graft polymerization of N-vinyl imidazole (VI) monomer , with and without crosslinker N,Nʹ-methylenbisacrylamide (MBAA) on/in a polysulfone (PSf) ultrafiltration (UF) substrate. A comprehensive characterization of the resulting composite membranes was conducted in terms of surface chemical composition (ATR-FTIR, XPS), surface morphology (SEM), surface charge (zeta potential), surface wettability (water contact angle) and barrier properties (water permeance, neutral solute/ions rejection and membrane stability). From rejection data of neutral solutes, including Vitamin B 12 and PEGs , the average pore sizes and pore size distributions of membranes were further determined. These results confirmed the prepared membranes as stable, defect-free, smooth, hydrophilic NF membranes with effective pore size between ~1.5 and 2 nm and water permeance between ~0.5 and 10 L m −2 h −1 bar −1 . Moreover, owing to the weak polybase characteristic of the incorporated PVI gel, the membranes would carry slight positive charge in neutral or slightly acidic solution. The small pore size membranes displayed high salt rejections in the order of MgCl 2 >NaCl≈MgSO 4 >NaSO 4 at near-neutral condition (pH 5.9±0.3).This testified their NF separation capability based on size exclusion, facilitated by Donnan repulsion. At last, by comparison with another reported type of gel-filled NF membranes with microporous substrate, and by applying a gel model, we delivered a qualitative description of the underlying fundamental parameters controlling the performance of such gel-filled membranes. Overall, these novel weak polybase gel-filled NF membranes with desirable nanometers-size pores and potentially tunable charge characteristics could offer great versatility for molecular-level separations.
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Journal of CO2 Utilization
·
2014
·
IF 0
Qingzhao Shi,Lishuai Jing,Weihong Qiao
Poor solubility of heavy hydrocarbons in CO 2 has limited the application of CO 2 -EOR (enhanced oil recovery) in modern oil recovery industry to some extent. Therefore, it is crucial to investigate the solubility regularity of different hydrocarbons in supercritical carbon dioxide (scCO 2 ) in the first place. In this paper, our objective is to explore the solubility of n -alkanes (C 6 H 14 –C 18 H 38 ) in scCO 2 . To measure cloud point pressures, the experiment utilizes high-pressure view chamber, and results for accuracy and repeatability of the experimental method and instrument are evidently positive. Then, cloud point pressures for n -alkanes from 318 K to 343 K show a proximately linear and positive correlation with the temperature; they also increase with expanding chain length of n -alkanes. In addition, the result of x (molar fraction of n -alkane at cloud point pressure) indicates that x has a positive correlation with the pressure at identical temperature, and when pressure is constant, temperature increase will reduce x . Finally, relationship studies between density of CO 2 and x reveal that, density of CO 2 has a positive influence on the solubility of n -alkane, and the Chrastil model corrects ln ρ and ln S data. The measured data align with the Chrastil model, with a maximum AARD value of 9.85%.
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GLYCOCONJUGATE JOURNAL
·
2015
·Vol. 32
·期 8
·643-653
·
IF 2.52
Liang Qun Tao,Du Jia Yan,Fu Qing,Lin Jiang Hui,Wei Zheng
The rare N-unsubstituted glucosamine (GlcNH 3
+ ) residues in heparan sulfate (HS) have important biological and pathophysiological roles. Therefore, the ability to chemically generate a series of oligosaccharides, which have a similar structure to the naturally-occurring, GlcNH 3
+ - containing oligosaccharides from HS, would greatly contribute to investigating their natural role in HS. In this study, a hexasaccharide library that possess GlcNH 3
+ residues were prepared from the chemical modification of the fully sulfated dp6. Chemical reaction conditions were optimized to generate different pattern of GlcNH 3
+ - containing oligosaccharides, then the structure of the library was detected by high-performance liquid chromatography-ion trap/time-of-flight mass spectrometry (LC/MS-ITTOF) analysis. EIC/MS and MS 2 analysis showed different fragmentation patterns of dp6s with different GlcNH 3
+ residues. This provides a foundation for further identification and quantification of GlcNH 3
+ - oligosaccharides by mass spectrum analysis.
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JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2014
·Vol. 52
·期 1
·284-295
·
IF 0.873
F. Zhang,H. Chang,W. Wei
A facile and efficient KOH-oriented regioselective ring-opening reaction for the acetolysis of N -tosylaziridines in DMSO was developed under mild conditions. This operationally simple protocol could tolerate a variety of functionalized carboxylic acids as well as several N -tosylaziridines. Moreover, this strategy provided the corresponding ring-opening products with good results.
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ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Bingbin Wu,Xiaoyu Jiang,Lifen Xiao,Wenhua Zhang,Jiaxin Pan,Xinping Ai,Hanxi Yang,Yuliang Cao
Sulfur has the highest redox capacity in all the solid electrode materials but its application for Li-S batteries is restricted by its poor cycleability due to the dissolution of its polysulfide intermediates produced during charge and discharge reactions. To solve this problem, we proposed a new strategy to suppress the dissolution of the polysulfide intermediates and the agglomeration of the discharge products through surface-modification of the sulfur electrode by in-situ electropolymerized poly(N-methylpyrrole) (PNMP). The PNMP-modified sulfur electrode exhibits stable surface morphology during charge and discharge, effectively depressing the structural collapse of the sulfur electrode. The charge-discharge measurements reveal that the PNMP-modified S/C electrode can deliver the same high reversible capacity as the bare electrode but demonstrate a much improved cycling stability with excellent capacity retention of 78.1% over 200 cycles with respect to the discharge capacity in the third cycle, considerably higher than that of the bare electrode (59.8%). In addition, this surface modification method is simple and affordable, providing a feasible way for improving the long-term cycleability of Li-S batteries.
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VACCINE
·
2014
·
IF 3.485
Qingfeng Liu,Chi Zhang,Xiaoyao Zheng,Xiayan Shao,Xi Zhang,Qizhi Zhang,Xinguo Jiang
The frequent outbreak of respiratory infectious diseases such as influenza and pulmonary tuberculosis calls for new immunization strategies with high effectiveness. Nasal immunization is one of the most potential methods to prevent the diseases infected through the respiratory tract. In this study, we designed a water-soluble system based on antigen/ N -trimethylaminoethylmethacrylate chitosan conjugates for nasal immunization. N -trimethylaminoethylmethacrylate chitosan (TMC) was synthesized by free radical polymerization of chitosan and N -trimethylaminoethylmethacrylate chloride and identified by 1 H NMR and FT-IR. Thiolated ovalbumin (OVA) was covalently conjugated to maleimide modified TMC with high conjugation efficiency. OVA conjugated TMC (OVA–TMC) significantly increased uptake of OVA by Raw 264.7 cells, which was 2.38 times higher than that of OVA/TMC physical mixture (OVA + TMC) at 4 h. After nasal administration, OVA–TMC showed higher transport efficiency to superficial and deep cervical lymph nodes than OVA + TMC or OVA alone. Balb/ C mice were intranasally given with OVA–TMC three times at 2-week internals to evaluate the immunological effect. The serum IgG, IgG1 and IgG2a levels of the OVA–TMC group were 17.9–87.9 times higher than that of the OVA + TMC group and comparable to that of the intramuscular group. The secretory IgA levels in nasal wash and saliva of the OVA–TMC group were 5.2–7.1 times higher than that of the OVA + TMC group while the secretory IgA levels of the intramuscular alum-precipitated OVA group were not increased. After immunofluorescence staining of nasal cavity, IgA antibody secreting cells were mainly observed in the lamina propria regions and glands of nasal mucosa. OVA–TMC showed little toxicity to the nasal epithelia or cilia of rats after nasal administration for three consecutive days. These results demonstrated that antigen conjugated TMC can induce both systemic and mucosal immune responses after nasal administration and may serve as a convenient, safe and effective vaccine for preventing respiratory infectious diseases.
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PubMed
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FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Keyi Wu,Yonghong Hu,Wenge Yang,Tuan Zhang,Qirun Guo,Shouhai Yang,Ying Shi
The solubility of N-Ethylcarbazole in methanol, ethanol, n-propanol, isopropanol, 1-butanol, 1-pentanol and petroleum ether was measured over the temperature range of 279.15–319.15 K at around 4 K intervals under atmospheric pressure. Experimental result showed that the solubility of N-Ethylcarbazole in seven solvents increased with the increasing temperature and they were in good agreement with the calculated solubility of the modified Apelblat equation and the λh equation. The thermodynamic properties of the solution process, including the Gibbs energy , enthalpy, and entropy were calculated by the van’t Hoff analysis. The values of both the standard molar enthalpy change and standard molar Gibbs energy change of solution were positive, which indicated that the process was endothermic.
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CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Xiufang Yan,Zhiqiang Jie,Lianhong Zhao,Hong Yang,Shiping Yang,Jie Liang
Novel polymeric micro/nano particles (MNPs) containing amide functional groups, poly (styrene-co-N-(t-Bu)-acrylamide) (PSA-NH) MNPs, have been synthesized by a copolymerization of styrene and acrylic acid and then an amination with tert-butylamine. The as-synthesized PSA-NH MNPs were converted to antibacterial polymeric MNPs containing N-halamine groups, poly (styrene-co-N-(t-Bu)-N-chlorine-acryl amide) (PSA-N-Cl) MNPs, by a facile chlorination in diluted NaOCl solution. The as-prepared PSA-N-Cl MNPs were characterized by field emission scanning electron microscopy (FE-SEM), Brunauer–Emmet–Teller (BET) analysis, X-ray photoelectron spectra (XPS), and Fourier Transform infrared spectroscopy (FTIR). Antibacterial tests showed that the as-prepared PSA-N-Cl MNPs possess powerful antibacterial activity against both Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). Minimum inhibitory concentration (MIC) values of PSA-N-Cl MNPs against E. coli and S. aureus were 0.20 μg/mL, whereas minimum bactericidal concentration (MBC) values of them against E. coli and S. aureus were 5.00 and 7.00 μg/mL, respectively. The storage stability test indicated that PSA-N-Cl MNPs are very stable under common storage conditions.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Mi Wang,Yanfeng Gao,Chuanxiang Cao,Kaimin Chen,Yicun Wen,Dingye Fang,Li Li,Xuhong Guo
Thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) microgel colloids were prepared by using water and high-boiling alcohol as binary solvent. Their thermosensitive behavior and solar modulation ability were studied by differential scanning calorimetery, ultraviolet–visible–near-infrared spectrophotometery, dynamic light scattering, and rheology. Effects of alcohol content and cross-linker dose on their microstructures and optical properties were investigated. A model house was constructed to test their energy-saving performance in smart windows. It was found that the solar modulation ability of PNIPAAm microgel colloids decreased with increasing N,N′-methylenebis(acrylamide) (BIS) dose or alcohol content. Compared to glycol, glycerol showed better compatibility with PNIPAAm hydrogels, inducing less deterioration of the solar modulation ability. With 0.1 wt % (of NIPA) BIS, when glycerol was added as a cosolvent, the prepared PNIPAAm microgel colloids exhibited spherical morphology, controllable LCST, short response time, suitable viscosity, low freezing point, restrained evaporation rate, and excellent energy-saving performance, which makes them much better candidates for application in smart windows than those using a single solvent.
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ADVANCED MATERIALS
·
2013
·Vol. 25
·期 40
·5762-5766
·
IF 14.829
Congcheng Fan,Arjan P. Zoombelt,Hao Jiang,Weifei Fu,Jiake Wu,Wentao Yuan,Yong Wang,Hanying Li,Hongzheng Chen,Zhenan Bao
Graphical Organic single-crystalline p-n junctions are grown from mixed solutions. First, C 60 crystals (n-type) form and, subsequently, C8-BTBT crystals (p-type) nucleate heterogeneously on the C 60 crystals. Both crystals continue to grow simultaneously into single-crystalline p-n junctions that exhibit ambipolar charge transport characteristics. This work provides a platform to study organic single-crystalline p-n junctions.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Xing Jiang,Dongxu Zhou,Xueliang Huang,Weifeng Zhao,Changsheng Zhao
In this study, we provided a facile method to prepare adsorbents with high content of amino groups for bilirubin removal. Poly (glycidyl methacrylate- co -N-vinylpyrrolidone) particle adsorbents were prepared through free radical solution copolymerization followed by a phase inversion technique. Amino groups were further introduced onto the particles by grafting 1,6-hexanediamine molecules. The porosity and specific surface area of the functional particles were 92.9% and 11.8 m 2 /g, respectively. Flourier transform infrared spectroscopy and elemental analysis confirmed the successful functionalization of polymeric particles. The cross-linker content and N-vinylpyrrolidone ratios had significant influence on the pore structure of the polymeric particles, as observed by scanning electron microscopy. Batch adsorption experiments were performed to verify bilirubin adsorption behavior of the particles, and a particle column was fabricated to further study the bilirubin removal. The particles exhibited good adsorption capacity of bilirubin without procoagulant activity , and had great potential to be used in hemoperfusion. The study opens a new route to fabricate functional polymer adsorbents.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 43
·
IF 1.768
Xiaoqin Chen,Zuliang Liu,Weiwei Cao,Chunyan Yong,Xiaodong Xing
A viable method for coating of cellulose fiber with quaternarized N-halamine is reported in this article. The use of quaternary ammonium salt group in combination with N-halamine group can reinforce the antibacterial activity. The chemical structure of as-synthesized N-halamine precursor 4-(Bromo-acetic acid methylester)-4-ethyl-2- oxazolidinone (BEO) was characterized by 1 H-NMR. The cellulose fibers were characterized by Fourier transform infrared spectra and X-ray photoelectron spectra. The spectra data confirmed that the quaternarized N-halamine-grafted cellulose fibers were successfully obtained. The antibacterial properties of functional fibers were challenged with both Gram positive and Gram negative bacteria. The antibacterial tests and showed that the as-prepared antibacterial cellulose fibers exhibited powerful and rapid bactericidal performance against both Gram negative E. coli and Gram positive S. aureus . © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42702.
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