JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
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2017
·Vol. 94
·期 9
·1153-1164
·
IF 1.421
Yang Shu,Li Guode,Saleh Ahmed S. M.,Yang Hongli,Wang Na,Wang Peng,Yue Xiqing,Xiao Zhigang
β-Sitosterol (Sit) and stearic acid (SA) were combined at varying ratios (w/w) and added to sunflower oil (SFO) at the concentration of 20 g/100 g oil for preparing edible fat-like oleogel. The oleogel was characterized using an optical microscope, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), differential scanning calorimeter, and texture analyzer. The oil-binding capacity, melting temperature, and firmness of the oleogel increased with the increase in the amount of SA in the gelator combination (Sit:SA, w/w). The microscopic analysis showed that the gel network formed based on the crystallization and self-organization of gelator molecules, and both gelators showed an independent crystalline behavior in the oleogel. In addition, the FTIR spectra showed that the gel network formed via physical entanglements and was stabilized by non-covalent interactions such as hydrogen bonding. Furthermore, XRD diffraction patterns indicated high lateral packing of molecular layers in oleogel prepared with the Sit and SA combination compared with oleogel prepared with a single gelator. On the other hand, for studying the effect of varying concentrations of gelator combinations, the Sit3:SA2 (w/w) combination was added to SFO at concentrations of 10, 15, 20, 25, and 30 g/100 g oil. Specific characteristics such as the oil-binding capacity and firmness of the oleogel improved as the concentration of the gelator combination (Sit3:SA2) increased from 10 up to 30 g/100 g oil. Therefore, it can be concluded that the saturated fat alternative oleogel can be prepared from SFO with a specific Sit and SA combination ratio and concentration.
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高影响因子
FIBERS AND POLYMERS
·
2017
·Vol. 18
·期 7
·1250-1254
·
IF 1.113
Chen Yingbo,Liu Huiqiang,Hu Xiaoyu,Cheng Bowen,Liu Dongqing,Zhang Yufeng,Nair Sankar
Membranes with high water permeation capability as well as high rejection to dye molecules are very important for dye separation. In this study, a metal organic framework structure (Cu-BTC) was fabricated in situ on a poly(vinyl difluoride) hollow fiber support for nanofiltration of dye solution. In order to protect the Cu-BTC layer, the surface was coated by crosslinking polyvinyl alcohol. The composite membranes showed no rejection to divalent salts and high rejection to Congo Red dye. It was noticed that several Cu-BTC layers could enhance dye rejection of the composite membranes. This novel composite membrane showed promising applications in the separation of dye molecules from aqueous solutions containing dissolved salts.
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高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 9
·3513-3519
·
IF 4.58
Huang Yicun,Yan Fanyong,Xu Jinxia,Bian Yuyao,Zhang Ruiqi,Wang Jie,Zhou Xuguang
The authors describe the synthesis of a two-dimensional organic-inorganic perovskite of the type NH 3 (CH 2 ) 10 NH 3 )PbBr 4 by a fast precipitation method. The resulting powder under photoecitation at 270 nm exhibits yellow luminescence (peaking at 550 nm) in DMSO/water mixtures if the ratio is bigger than 4/6. On addition of Hg(II) and a rhodamine spirolactam, ring opening occurs and colorimetric and fluorescent responses can be seen. Specifically, the emission at 550 nm gradually decreases and a new emission peak appears at 585 nm (corresponding to the emission peak of RBEA-Hg(II) complex) while the color of the solution gradually turns to pink under visible light. The emission peak of the modified perovskite overlaps the 585 nm absorption of rhodamine B, and this results in a FRET effect whose Förster radius (donor-acceptor distance) is calculated from decay time data to be 10.4 Å. Based on these findings, a FRET-based assay for Hg(II) was worked that has a 2.4 μM detection limit.
In DMSO/H 2 O = 1/9 mixed solution, energy transfer from NH 3 (CH 2 ) 10 NH 3 )PbBr 4 (C 10 PbBrPE) to rhodamine B occurred. Fluorescence resonance energy transfer (FRET) process is available by rhodamine B ethylenediamine and C 10 PbBrPE for detection of Hg(II).
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CHEMICAL PAPERS
·
2017
·Vol. 71
·期 8
·1481-1489
·
IF 1.258
Zhang Hong-Yan,Liu Kai-Kai
There is of great interest in promotion of anti-thermal aging properties of natural rubber (NR) to improve the applicability. In this study, two novel Schiff base antioxidants (SBAOs) for NR were synthesized utilizing 4-aminodiphenylamine with 3,5-Di-tert-butyl-2-hydroxybenzaldehyde or cinnamic aldehyde in an ethanol medium. IR, 13 C-NMR, and 1 H-NMR confirmed the structures of SBAOs. Addition of SBAOs improved the rheometric properties, mechanical properties and thermal oxidative stability of NR vulcanizates. Introduction of SBAOs in NR increased the apparent activation energy of thermal oxidative degradation according to Kissinger and FWO methods. Anti-thermal aging performance of SBAOs for NR is related to the structures. The C=N double bonds in SBAOs improve the electron density of Ar–OH and/or Ar–NH–Ar structures, benefiting the release of active hydrogen. The active hydrogen could capture free radicals initiated during the thermal oxidative aging process. The lone pair electrons on nitrogen atom are also beneficial to delay or terminate free radical reaction. NR with SBAOs showed high mechanical properties of the tensile strength, tensile stress at 100% elongation and Shore A hardness compared to commercial BHT and 4010 during aging 96 h. It indicates potential applications of SBAOs as efficient antioxidants for NR.
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高影响因子
Science Bulletin
·
2016
·
IF 0
Xiaoping Liu,Hao Qin,Weiliu Fan
Band offset is a dominant factor affecting the photocatalytic performance of heterostructure photocatalysts . Therefore, controlling the band gap structure of semiconductors is a key challenge in the development of efficient photocatalysts. We used a typical in situ-method to prepare diverse graphite-phase carbon nitride (g-C 3 N 4 ) samples from melamine , thiourea , and a mixture thereof, and found that they exhibited band gaps between 2.3–2.8 eV. From UV–Vis spectra and X-ray photoelectron spectroscopy measurements, we determined that the g-C 3 N 4 samples exhibited different band gap values and valence band positions. On this basis, we constructed g-C 3 N 4 /m-LaVO 4 heterojunctions with different band offsets. UV–Vis spectra and X-ray photoelectron spectroscopy measurements revealed that the valence band offsets (VBOs) of the different heterojunctions were similar, but their conduction band offsets (CBOs) were significantly different. Photocatalytic experiments revealed that the reaction rate was enhanced with an increase in the CBO value. Furthermore, the three-phase g-C 3 N 4 /g-C 3 N 4 /m-LaVO4 heterojunction composed of m-LaVO4 and mixed g-C 3 N 4 showed the highest photocatalytic activity , which was mainly due to the construction of a multilevel structure. This work investigates the influence of the band offset on heterojunction photoelectrochemical properties and provides a new strategy to improve the photocatalytic activity by constructing multilevel structures.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2016
·Vol. 28
·期 3
·2769-2774
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IF 1.798
Yu Qi,Chen Hanlin,Chen Ping,Wang Qi,Lu Chun,Jia Caixia
Carbon nanofibers containing Fe 3 O 4 nanoparticles (Fe 3 O 4 @C nanofibers) were synthesized by electrospinning technique followed by heat treatment, and then the as-prepared nanofibers were loaded in bismaleimide (BMI) resin to prepare nanocomposites. The phase structure and morphology of nanofibers were characterized by X-ray diffraction and scanning electron microscope, respectively. The complex permittivity and permeability of nanocomposites were measured by vector network analyzer using a coaxial line method in the frequency range of 1–18 GHz, and the microwave absorption performance was accordingly evaluated. The results indicated that the Fe 3 O 4 @C nanofibers/BMI composites showed excellent low-frequency electromagnetic wave absorption properties with a minimum RL value of −22 dB at 2.1 GHz corresponding to a thickness of 6 mm and exceeding −10 dB with thickness of 3–6 mm in the whole S band (2–4 GHz). The strong absorption in low frequency is attributed to good matching characteristics of dielectric loss and magnetic loss, which can be efficiently tailored by combination of magnetic Fe 3 O 4 and dielectric carbon layer through electrospining technology. The novel Fe 3 O 4 @C nanofibers loaded in BMI resin can provide an effective solution for pressing problem in present that how to produce lightweight microwave absorbing nanocomposites with excellent low-frequency electromagnetic absorption properties.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2016
·Vol. 24
·期 1
·558-567
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IF 2.76
Zhai Pingping,Chen Xuan,Dong Wenbo,Li Hongjing,Chovelon Jean-marc
This study aimed to investigate the degradation of triclosan (TCS) in the presence of p -aminobenzoic acid (PABA) under simulated sunlight irradiation ( λ ≥ 290 nm). The effect of PABA concentration, pH, dissolved organic matter (DOM), and DOM-hydrolytic Fe(III) species complexes on the photodegradation of TCS in the presence of PABA (TCS -PABA ) was also studied. The photolysis of TCS -PABA obeyed pseudo-first-order kinetics well, and the degradation of TCS -PABA enhanced with increasing solution pH (from 3.0 to 11.0). The presence of PABA inhibited the degradation of TCS -PABA , and the weakest inhibitory effect was observed while the concentration of PABA was 5 mg L −1 . The addition of DOM (Suwannee River fulvic acid standard I [SRFA], Suwannee River HA standard II [SRHA], and Suwannee River natural organic matter [SRNOM]) showed different inhibition effects on TCS -PABA degradation. However, higher Fe(III) concentration at the DOM concentration of 5 mg L −1 could favor the formation of DOM-hydrolytic Fe(III) species complexes, further accelerating the degradation of TCS -PABA . In comparison with deionized water (DI water), TCS -PABA could be better photodegraded in river water nearby the effluent of a wastewater treatment plant. This study provides useful information for understanding the natural behavior of TCS in the presence of other organic contaminants.
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PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 22
·期 5
·1195-1203
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IF 1.108
Wu Qigang,Xu Rong,Li Jing,Zhang Qi,Zhong Jing,Huang Weiqiu,Gu Xuehong
The compact ZIF-69 membranes have been prepared by seeded growth method for the recovery of gasoline vapor which is a major challenge in the petrochemical industry. The membrane performances for separating N 2 /n-alkane mixtures at various operating conditions (e.g. trans-membrane pressure difference, operating temperature, feed concentration, and stage cut) were systematically investigated. The highest separation factor was 2.60 with the corresponding permeance of 5.02 × 10 −8 mol/(m 2 s Pa) for the N 2 /n-C 6 H 14 model mixtures. Moreover, the effects of n-alkane components (n-C 5 H 12 , n-C 6 H 14 , and n-C 7 H 16 ) on the separation performances were studied, and the separation factors followed α (N 2 /n-C 7 H 16 ) > α (N 2 /n-C 6 H 14 ) > α (N 2 /n-C 5 H 12 ), due to the different adsorption capacities of n-alkanes on ZIF-69 materials. The present work demonstrates that the ZIF-69 membrane is a highly promising candidate for the application in gasoline vapor recovery.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 11
·3860-3874
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IF 2.371
Chen Wen-Qiu,Li Quan-Tao,Li Peng-Hui,Zhang Quan-Yuan,Xu Zu-Shun,Chu Paul K.,Wang Xian-Bao,Yi Chang-Feng
Reduced graphene oxide/polyimide (rGO/PI) nanocomposites are prepared via in situ random co-polycondensation of amino-modified and chemically reduced graphene oxide (rGO-NH 2 ) with commercial diamine and dianhydrides. The chemical modification and reduction of graphene oxide (GO) endows rGO-NH 2 with good solubility in organic solvents to prepare rGO/PI nanocomposites with high filler contents. rGO-NH 2 is further used as a functional co-monomer to participate the polymerization of PI with full compatibility of the guest and host in molecular level. With the addition of rGO-NH 2 at 2 wt% content, the thermal, mechanical properties, and hydrophobicities of rGO/PI nanocomposites are significantly enhanced with various indicators achieving or approaching the optimum. The positive or negative impacts of rGO-NH 2 with various contents to the properties of the obtained nanocomposites are also illustrated incidentally from micromorphology. This effective approach provides a possibility for developing high-performance PI composites based on graphene for advanced engineering or functional materials.
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高影响因子
CHROMATOGRAPHIA
·
2013
·Vol. 76
·期 11
·671-678
·
IF 1.437
Cui Shumin,Chen Qianxia,Wang Weiping,Miao Jigen,Wang Aijun,Chen Jianrong
In this study, a simple and efficient method has been developed to analyze pesticides in water samples using ultrasonic-assisted dispersive liquid–liquid microextraction (UA-DLLME) combined with gas chromatography-flame ionization detection (GC-FID). Several parameters, including type and volume of extractant and dispersant, extraction time, and amount of salt on extraction performance, were optimized in detail. A mixture of acetonitrile (1.0 mL, dispersant) and carbon tetrachloride (15 μL, extractant) was used for extraction. Under optimal conditions, enrichment factors were obtained between 315 and 1153. The linearity of the method ranged from 1 to 100 μg L −1 with correlation coefficients ≥0.9990. Limits of detection (S/N = 3) ranged between 0.09 and 0.57 μg L −1 , depending on the compounds. Relative standard deviations were <8.0 % ( n = 5) for both intra- and inter-day analyses. The proposed method was successfully applied for the preconcentration and determination of pesticides in water samples (river water, tap water, and lake water) with recoveries that varied from 90.5 to 107.7 %.
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高影响因子
Chemistry Central Journal
·
2013
·Vol. 7
·期 1
·1-11
·
IF 1.312
Zuo Ping-Ping,Feng Hua-Feng,Xu Zhi-Zhen,Zhang Ling-Fan,Zhang Yu-Long,Xia Wei,Zhang Wen-Qing
Background Graphene oxide (GO)can be dispersed through functionalization, or chemically converted to make different graphene-based nanocomposites with excellent mechanical and thermal properties. Chitosan, a partially deacetylated derivative of chitin, is extensively used for food packaging, biosensors, water treatment, and drug delivery. GO can be evenly dispersed in chitosan matrix through the formation of amide linkages between them, which is different from previous reports focusing on preparing GO/chitosan nanocomposites through physical mixing. Results In this study, free-standing graphene oxide-chitosan (GO-chitosan) nanocomposite films have been prepared. The GO-chitosan films are biologically compatible and mechanically reinforced. Through the formation of amide linkages between GO’s carboxylic acid groups and chitosan's amine groups, GO could be evenly dispersed within the chitosan matrix. We also characterized the GO-chitosan composite films using element analysis, Fourier transform infrared spectroscopy, X-ray photo electron spectroscopy, differential scanning calorimetry, and thermo gravimetric analysis. Compared to pristine chitosan film, the tensile strength of GO-chitosan film is improved by 2.5 folds and Young’s modulus increases by nearly 4.6 folds. The glass transition temperature of GO-chitosan composite film shifts from 118°C to 158°C compared to the pristine chitosan, indicating its enhanced thermal stability. GO-chitosan composite film was also evaluated for its biocompatibility with C3H10T1/2 cells by in vitro fluorescent staining. The graphene oxide-reinforced chitosan composite films could have applications in functional biomaterials. Conclusion The present study describes a useful and simple method to chemically attach biocompatible chitosan onto graphene oxide. We envision that the GO-chitosan film will open avenues for next-generation graphene applications in the realm of functional biomaterial.
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PubMed
高影响因子
Science China-Chemistry
·
2013
·Vol. 56
·期 5
·567-575
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IF 1.327
Xiang Ting,Zhang ZuLei,Liu HaiQing,Yin ZhengZhi,Li Lei,Liu XiaoMing
Nanofiber membranes from the composite of cellulose acetate/polyvinylpyrrolidone were prepared using electrospinning technique. After treated with water and alcoholic KOH to remove partially polyvinylpyrrolidone and deacetylate the cellulose acetate, the membranes were further functionalized with thiol groups using thioglycolic acid. Related materials were characterized using infrared and thermogravimetric analysis. And the results showed that the membranes were success of functionalisation. Then the nanofiber membranes were used in the sorption-desorption process. The effects of pH, contacting time and adsorption capacity of nanofiber membranes were studied against Cu(II), Cd(II) and Pb(II) ions. And the maximum adsorption capacities of Pb (II), Cu (II), and Cd (II) ions were estimated at 30.96, 19.63, 34.70 mg g −1 . Our results suggested that the adsorption behaviour of metal ions could be described using Langmuir model. Their adsorption kinetics was in agreement with the model of pseudo-second order, suggesting chemical adsorption as the rate-limiting step of the adsorption mechanism. The durability of the thiol-functionalized cellulose nanofiber membranes was also evaluated by repetitive adsorption-desorption.
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