CARBON
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2021
·
IF 9.594
Chao Liu,Qing Yin,Wenbo Zhang,Yan Bao,Peipei Li,Lifen Hao,Jianzhong Ma
In order to improve the tribological properties of graphene reinforced polymer composites , ionic liquids (IL) and carbon quantum dots (CQDs) were deposited on the reduced graphene oxide (rGO) nanosheets surface to ameliorate the compatibility between graphene and bismaleimide (BMI) matrix, as well as the stability of their self-lubricating transfer films. Their tribological properties were evaluated, and the wear mechanism was studied by means of surface/interface analysis, respectively. It could be found that CQDs/IL/rGO could improve the stability of the friction coefficient and decrease the volume wear rate of their BMI composites. When the filler amount was only 0.6 wt%, the friction coefficient and volume wear rate of CQDs/IL/rGO/BMI composites decreased by 41.2% and 94.7% compared with the neat BMI, respectively. Also, the CQDs/IL/rGO/BMI composites exhibited the lowest friction coefficient fluctuations and volume wear rate than those of other composites. Because of the synergistic effects of the CQDs, IL and rGO, uniform, continuous and steady self-lubricating transfer film could be formed during the friction process , thus significantly improving the anti-friction and wear-resistance properties of CQDs/IL/rGO/BMI composites. More importantly, the unique combinations of advantages of each functional component can also be applied in many other fields, such as catalysis, chemical sensors, etc.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Munir Hussain,Sohail Yasin,Muhammad Adnan Akram,Huilong Xu,Yihu Song,Qiang Zheng
Nanoparticle dispersion is important for the performance of rubber compounds. Herein, ionic liquids (ILs) and silane are used to prepare silica-filled butadiene rubber vulcanizates. The results show that replacement of a half of silane by ILs could greatly improve the dispersions of silica and zinc oxide, restrain the migration of sulfur and other additives inside the composite, and maintain the cross-linking degree of the matrix possibly by suppressing the adsorption of sulfur and other additives by silica. The regulated filler dispersity and matrix cross-linking strongly influence the dynamic rheological behaviors of the vulcanizates as a function of silica volume fraction. In comparison with silane, the introduction of ILs could improve the reinforcement effect, reduce energy dissipation, and lower the frequency dependences of loss modulus and loss tangent in the linear region.
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高影响因子
MOLECULES
·
2019
·Vol. 24
·期 18
·3223
·
IF 3.06
Xiu Liu,Linya Huang,Hongjun Chen,Na Li,Chao Yan,Chenzhong Jin,Hanhong Xu
To obtain highly selective toxic derivatives of fipronil, a series of Schiff bases with an alkynyl group (3a–3k) were designed and synthesized from 4-ethynylbenzaldehyde (2) and 4-substituted 5-amino-N-arylpyrazole (1a–1k) via a nucleophilic addition elimination reaction in ionic liquids. Utilization of ionic liquids was demonstrated to endow the yield of each compound beyond 50%, which was enhanced over 1.5 times of the synthetic productive rates comparing the conventional method by which longer reactive time was consumed. The derivatives were characterized via nuclear magnetic resonance hydrogen spectroscopy (1H-NMR), carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR), and electrospray ionization high resolution mass spectrometry (ESI-HRMS). The cytotoxicity of these derivatives onTrichoplusia ni(Hi-5) cell andSpodoptera lituracell (SL cell) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) bioassays. The results indicated that several compounds had potential cytotoxicity on Hi-5 cell, especially a 4-ethyl substituted alkynyl Schiff base derivative (3f) that was demonstrated to possess high selective toxicity to the Hi-5 cell than the SL cell. In addition,3fexhibited comparable toxic activity to commercial fipronil on a Hi-5 cell while a little toxic effect on the SL cell, which satisfied the expectation for selective toxicity screening.Keywords:N-arylpyrazole derivatives;schiff base;cytotoxicity;fipronil derivatives
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PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Yinpeng Wang,Junqi Nie,Cuifen Lu,Feiyi Wang,Chao Ma,Zuxing Chen,Guichun Yang
Polyimidazolium salts are a class of important catalysts for CO 2 cycloaddition with epoxides. However, initiator like azoisobutyronitrile or metal catalyst is often required to promote their synthetic process. Therefore, developing a clean route to synthesize polyimidazolium salts is still highly desirable. In this study, three crosslinked polymers PIM1, PIM2 and PIM3 containing imidazolium unit were constructed via nucleophilic substitution reaction of 1,3,5,7-tetrakis (4-(imidazole-1-yl)phenyl)adamantane and benzyl bromides. The structure and composition of the polymers were characterized by CP/MAS 13 C NMR, FT-IR and XPS. Different porosities were observed for PIMs, and PIM2 has a larger BET surface are than that of PIM1 and PIM3. Accordingly, the polymeric imidazolium salt PIM2 shows superior activity for catalyzing cyclic addition of CO 2 with a variety of epoxides without any solvent or cocatalyst, giving the cyclic carbonates in excellent yields. In addition, PIM2 shows high stability and easy recyclability.
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高影响因子
POLYMER TESTING
·
2019
·
IF 2.943
Yingying Zhou,Mingfeng Chang,Xiyu Zang,Lan Zheng,Yuqi Wang,Le Wu,Xiaolong Han,Yuqing Chen,Yunsong Yu,Zaoxiao Zhang
The CO 2 capture materials and technology have received much attention in recent years due to the environmental deterioration caused by the greenhouse gas emissions . Several imidazolium polymeric ionic liquids (PILs) were synthesized and immobilized on mesoporous γ-Al 2 O 3 (MA) using ultrasonic immersion method. The prepared adsorbents were characterized by FT-IR, 1 H NMR, EA , TGA , SEM, XRD , BET and TEM, indicating the successful synthesis of the desired PILs/MA. The CO 2 adsorption capacity was investigated under different loading ratios, temperatures, pressures and CO 2 flow rates , whose optimal adsorption conditions were 1/1, 313 K, 5 bar and 10 mL/min, respectively. Moreover, the adsorption curves for P[VCIm]Cl/MA were coincident with pseudo-second order model, and the CO 2 adsorption kinetics model was calculated and obtained. Compared with P[VRIm]Cl and P[VEIm]Cl, P[VCIm]Cl/MA demonstrated an outstanding adsorption amount of 0.562 mmol/g under the suitable conditions, and its regeneration efficiency could achieve 94.8% after 5 times cycle.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2019
·
IF 7.015
Jingyi Yang,Feiyun Sun,Lingyan Zhao,Ding Yu Xing,Wenyi Dong,Zijun Dong
Electric membrane bioreactor (E-MBR) for wastewater treatment and water purification has attracted significant interest due to its remarkable performance in fouling mitigation. The performance is much relevant to the electric and physicochemical properties of the conductive membranes in E-MBR. This study proposed a facile method to prepare a conductive membrane with low electrical resistance and enhanced hydrophilicity. Oxidative polymerization of pyrrole doping with ionic liquids was conducted on the surface of polyvinylidene fluoride (PVDF) membranes. Among the studied ionic liquids, 1-butyl-3-vinylimidazolium tetrafluoroborate (BVIMBF 4 ) was the most suitable in this work. The electrical resistance of the PVDF membrane modified by pyrrole and BVIMBF 4 (PPy-BVIMBF 4 /PVDF membrane) was as low as 9.76 Ω/sq, and its water contact angle reduced from 81° to 45°. In the fast-filtration tests, these conductive microfiltration membranes exhibited high rejections of Cu 2+ ions (~85%) and Ni + ions (~65%) and enhanced antifouling performance during the bovine serum albumin filtration with the application of an electric field. A long-term E-MBR operation demonstrated that the transmembrane pressure (TMP) rise and the flux decline of the PPy-BVIMBF 4 /PVDF membrane were significantly alleviated due to its improved conductivity and hydrophilicity. Its total membrane resistance for water transport was only 27% of the base PVDF membranes under a minute electric field of 0.8 V/m. Overall, the incorporation of ionic liquids in the oxidative polymerization of pyrrole offers a novel and effective strategy in conductive membrane fabrication and serves as an excellent method in fouling mitigation in MBR.
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高影响因子
Lubrication Science
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2019
·Vol. 31
·期 4
·127-136
·
IF 1.682
Zeyun Wang,Jun Chang,Wei Wu
A detailed study on the synergistic effects of phosphate ionic liquids (ILs) and rust inhibitor (octadecylaminen-oleoyl sarcosinate (T711)) in the complex lithium grease (G) at room temperature and 100°C is presented in this paper. The results indicate that the hybrid additives (T711-ILs-G) showed better friction-reducing and antiwear properties than single additives (T711-G and ILs-G). In the case of T711-ILs-G, the presence of T711 can prevent rustiness of the worn surface so the ILs can easily react with the exposed substrate surface and form tribological films on the sliding surfaces.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2019
·
IF 6.361
Hongbo Suo,Lili Xu,Chao Xu,Xiang Qiu,He Huang,Yi Hu
We prepared ionic liquids (ILs) modified magnetic alginate nanoparticles and used these as supports for lipase immobilization. The novel supports were characterized using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance ( 1 HNMR), vibrating sample magnetometry (VSM), thermogravimetry (TG), transmission electron microscopy (TEM) and water contact angle (WCA) measurements. The immobilized lipase (PPL-IL-MSA) exhibited high activity, 2.1-fold higher than that compared to free lipase and 1.59-fold higher compared to immobilized lipase without IL (PPL-MSA). In addition, the pH and temperature application range of PPL-IL-MSA were both found to be broader than that of free lipase and PPL-MSA. The thermal stability, denaturation stability, and reusing stability of PPL-IL-MSA were also higher than those of other samples. After 10 times of reuse, the residual activity of PPL-IL-MSA was 89.7% higher than that of PPL-MSA (84.4%). Furthermore, the kinetic constant K m of PPL-IL-MSA was 13.7 mg/mL lower than that of free lipase (21.2 mg/mL) and PPL-MSA (18.4 mg/mL). Circular dichroism (CD) was used to study the secondary structure of enzymes in order to explain the mechanism of the performance improvement of PPL-IL-MSA. This work involving the development of a new supports for enzyme immobilization may serve as a reference for further studies in this field.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Tingting Zhang,Guangli Yu,Xiaoqiang Liang,Nian Zhao,Feng Zhang,Fengyu Qu
Imidazolium based ionic liquids (denoted BMIM-ILs) with the altering anions (OH − , HCO 3 − and AcO − ) as ionic carriers were synthesized and bottle around ship introduced into the cages of zeolite-type metal organic frameworks (ZIF-8) as porous host, resulting in a series of anion-containing composites (BMIM-ILs/ZIF-8) with anion conducting. Bottle around ship method could integrate with the superiorities of BMIM-ILs and ZIF-8 for more excelling conduction and quite eliminate IL leakage. Besides, the hybrid membranes combined BMIM-ILs/ZIF-8 as fillers with polymer blends consisting of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) as matrix were assembled with varying weight percentages. The structures of the prepared composites and hybrid membranes were inspected. It should be noted that ZIF-8 encapsulating into BMIM-OH (6.8 × 10 −4 S cm −1 ) and BMIM-HCO 3 (1.08 × 10 −3 S cm −1 ) reveal two orders of magnitude increase in conductivity-values comparison to that of the parent framework (2.3× 10 −5 S cm −1 ) at 353 K and ∼98% relative humidity (RH). The hybrid membrane containing 30%BMIM-OH/ZIF-8 has the advantage in proton conductivity of 1.02 × 10 −3 S cm −1 at 353 K and ∼98% RH, which is 6.49 times higher than that of the ZIF-8/PVP/PVDF. The activation energies (E a ) of BMIM-OH/ZIF-8 and its hybrid membrane are calculated to be 0.15 eV and 0.23 eV, respectively. They could be regarded as a fast-ion conductor on the ground of high conduction and low activation energy, which make them bright outlooks and wonderful potential for electrochemical devices .
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Energy Science & Engineering
·
2019
·Vol. 7
·期 5
·2237-2246
·
IF 2.893
Yuan Zhao,Hao Xu,Kaifeng Lu,Yang Qu,Lingjun Zhu,Shurong Wang
In this study, the most abundant C5 carbohydrate unit in biomass, namely xylose, was chosen as the feedstock, and its hydrothermal conversion for furfural production was carried out in a green and renewable solvent system composed of water and butanone, in order to study the role of FeCl 3 and [bmim]Cl of ionic liquid catalyst in the conversion process of xylose. A key intermediate named xylulose from Lewis acid-catalyzed xylose isomerization was quantified. It was concluded that appropriate content of FeCl 3 and [bmim]Cl favored the isomerization-dehydration reaction path along which xylose was converted into furfural, while excessive amount of either component would result in side reactions leading to furfural consumption at long reaction times. By comparison between ionic liquid catalysts that had different active metal sites, xylose conversion and furfural yields were found to increase when the Lewis acidity of the metal ions became stronger. Moreover, chlorometallate anions with better catalytic performance than the original neutral salts were formed during catalyst preparation, and in this way, the xylose conversion and furfural formation were further promoted. Finally, the optimized ionic liquid catalyst produced a highest furfural yield of 75% and xylose conversion of 99% at 140°C.
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高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 4
·969-978
·
IF 2.372
Bian Yuhang,Zhang Juan,Liu Chaozheng,Zhao Dishun
Abstract Brӧnsted acidic poly ionic liquid (PIL-M) was successfully prepared by free-radical polymerization. The surface area of the heterogeneous catalyst was 301.1 m 2 /g. The result of thermogravimetric (TG) proved that PIL-M had good thermal stability (decompose at 410 °C). The optimal reaction condition was as follows: 6 wt% catalyst amount, reaction temperature 80 °C, the ratio of methanol to oleic acid 9:1 and reaction time 3 h. Under the optimal condition, the yield of methyl oleate was up to 95.9%. The excellent catalytic activity of PIL-M in the product of biodiesel benefit from its excellent properties such as high surface area (301.1 m 2 /g) and hierarchical nanopores. Compared with commercial resin (Amberlyst 15) and other catalysts, PIL-M showed better catalytic activity. The yield of methyl oleate was still over 90% after four times reuse. The structure of PIL-M kept stable after four times reuse, which was confirmed by the FT-IR spectrum. Graphic Abstract
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Yuqi Ke,Wenbin Jin,Qiwei Yang,Xian Suo,Yiwen Yang,Qilong Ren,Huabin Xing
The design of multifunctional ionic liquids (ILs) that integrate different attractive characteristics, such as strong hydrogen-bonding interactions, good lipophilicity, significant nanoscale organization, and low viscosity, in a molecular structure is of great importance for the application of ILs in extraction, biomass conversion, and catalysis but remains challenging. Here, we synthesized a family of novel phosphonium ILs featuring branched chain carboxylate anions with carbon number up to 18 and systematically characterized the physicochemical properties of prepared ILs. The branched chain carboxylate ILs (BCC-ILs) exhibit very strong hydrogen-bond basicity (β = 1.49–1.72, 30 °C) and excellent lipophilicity (π* = 0.73–0.95, 30 °C), and have obvious nanoscale segregation and moderate viscosity (η = 91.8–200.5 mPa, 40 °C). The d value of BCC-ILs ranged from 10.5 to 15.6 Å when the length of alkyl chain in anions or cation rose. These nanostructured solvents can undergo self-assembly processes with typical bioactive molecules of cholesterol to form highly ordered mesoscopic structures through cooperative hydrogen-bond and van der Waals interactions, which enable unprecedented high solubility of cholesterol in BCC-ILs (molar solubilities 0.31–1.12 at 50 °C). Additionally, we found that n-heptane had the significant synergistic effect on the dissolution of cholesterol molecules, and the introduction of n-heptane promoted the formation of highly ordered lamellar liquid crystals in the BCC-IL/cholesterol system. The dissolving mechanism of BCC-ILs for bioactive molecules was explored by experimental studies. This work indicates that the multifunctional BCC-ILs are promising solvents for extractions, catalysis, and biomass conversion.
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危险品化学品经营许可证（带存储）