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1.
Bio‐inspired synthetic method provides an effective shortcut to fabricate functional nanostructured materials with specific morphologies and designed functionalities. Natural cellulose substances (e. g., commercial laboratory cellulose filter paper) possesses unique three‐dimensionally cross‐linked porous structures and abundant functional groups for the functional modification on the surfaces. The deposition of metal oxide gel film on the surfaces of the cellulose nanofibers is facilely to be achieved through the surface sol‐gel process, resulting in metal oxide replicas of the initial cellulose substance or metal‐oxide/carbon nanocomposites. Moreover, the as‐deposited metal oxide gel films coated on the cellulose fiber surfaces provide ideal platforms for the further formation of specific functional assemblies, and eventually to the corresponding nanocomposite materials. Based on this methodology, various nanostructured composites were prepared and employed as anodic materials for lithium‐ion batteries, including metal‐oxides‐based (such as SnO2, TiO2, MoO3, FexOy, and SiO2) and Si‐based composites, as summarized in this personal account. Benefiting from the unique hierarchically porous network structures and the synergistic effects among the composite components of the anodic materials, the transfer of electrons/ions is accelerated and the structural stability of the electrode is enhanced, leading to the improved lithium storage performances and promoted cycling stability. 相似文献
2.
M. U. AnuPrathap Balwinder Kaur Rajendra Srivastava 《Chemical record (New York, N.Y.)》2019,19(5):883-907
Electrochemical sensors have drawn significant attention over the last couple of decades because of their ability to improve detection of organic and inorganic analytes found in the field of biotechnology, environmental sciences, medicine, and food quality control. This personal account summarizes the state‐of‐art research carried out in the construction and evaluation of nanostructured metal oxides and zeolite based electrochemical sensors. Metal oxides and zeolite‐based nanomaterials have many unique and extraordinary properties such as tunable redox activity, surface functionalization ability, optimum conductivity, large surface area, biocompatibility and so forth. In this personal account, the current advances in electrochemical sensor applications of metal oxides, zeolite‐based nanomaterials, and their nanocomposites are described for the single and simultaneous determination of organic & inorganic contaminants present in water bodies, physiological bio‐molecules present in human blood & urine samples, and organic contaminants present in food materials.Moreover, concluding section focuses discussion on the future developments and applications of these materials in various emerging technologies. 相似文献
3.
Ionic‐liquid‐based ultrasound/microwave‐assisted extraction of 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one and 6‐methoxy‐benzoxazolin‐2‐one from maize (Zea mays L.) seedlings 下载免费PDF全文
Chunying Li Zhicheng Lu Chunjian Zhao Lei Yang Yujie Fu Kunming Shi Xin He Zhao Li Yuangang Zu 《Journal of separation science》2015,38(2):291-300
We evaluated an ionic‐liquid‐based ultrasound/microwave‐assisted extraction method for the extraction of 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one and 6‐methoxy‐benzoxazolin‐2‐one from etiolated maize seedlings. We performed single‐factor and central composite rotatable design experiments to optimize the most important parameters influencing this technique. The best results were obtained using 1.00 M 1‐octyl‐3‐methylimidazolium bromide as the extraction solvent, a 50°C extraction temperature, a 20:1 liquid/solid ratio (mL/g), a 21 min treatment time, 590 W microwave power, and 50 W fixed ultrasonic power. We performed a comparison between ionic‐liquid‐based ultrasound/microwave‐assisted extraction and conventional homogenized extraction. Extraction yields of 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one and 6‐methoxy‐benzoxazolin‐2‐one by the ionic‐liquid‐based ultrasound/microwave‐assisted extraction method were 1.392 ± 0.051 and 0.205 ± 0.008 mg/g, respectively, which were correspondingly 1.46‐ and 1.32‐fold higher than those obtained by conventional homogenized extraction. All the results show that the ionic‐liquid‐based ultrasound/microwave‐assisted extraction method is therefore an efficient and credible method for the extraction of 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one and 6‐methoxy‐benzoxazolin‐2‐one from maize seedlings. 相似文献
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5.
Shiqian Gao Wei Yu Xiao Yang Zhonglin Liu Yilong Jia Hanqi Zhang 《Journal of separation science》2012,35(20):2813-2821
On‐line continuous sampling, ionic liquid‐based dynamic microwave‐assisted extraction high performance liquid chromatography has been developed and applied to the extraction of lipophilic constituents from root of Salvia miltiorrhiza Bunge. Several operating parameters were optimized by single‐factor and Box–Behnken design experiments. The type and concentration of ionic liquids, power of microwave irradiation, flow rate of sample suspension, amount, and particle size of sample were investigated. The limits of detection for tanshin‐one I, cryptotanshinone, and tanshinone IIA are 0.014, 0.009, and 0.009 mg/g, respectively. The RSDs of interday and intraday were lower than 2.02 and 2.16%, respectively. The recoveries for target analytes were in the range of 90.7–101.8%. The homogeneity of the suspension and stability of the analytes were investigated and the results were satisfactory. The proposed method was compared with the off‐line ionic liquid‐based dynamic microwave‐assisted extraction, off‐line ethanol‐based dynamic microwave‐assisted extraction, ionic liquid‐based ultrasonic‐assisted extraction, and ionic liquid‐based maceration extraction. The results indicated that the proposed method is effective for the extraction of the active components in Chinese herbal medicine and has some advantages over the other methods. 相似文献
6.
Developing simple, rapid, and environmentally friendly synthetic methodologies for the preparation of functional nanomaterials is of great importance for broadening and improving their potential applications. In comparison with other methods, the microwave-assisted hydrothermal method possesses and combines the merits of microwave and hydrothermal methods, which can achieve the high temperature and high pressure for a short time from several minutes to several hours in a closed reaction system. In this review, the synthesis of various types of functional nanomaterials such as metals oxides, metal composite oxides, inorganic biomaterials (hydroxyapatite and calcium carbonate), and metal sulfides via the microwave-assisted hydrothermal method is summarized. The special properties and applications of functional nanomaterials by the microwave-assisted hydrothermal method are compared with others methods. The future developments of this promising method are put forward. 相似文献
7.
Xiao‐Juan Li Hui‐Min Yu Chang Gao Yuan‐Gang Zu Wei Wang Meng Luo Cheng‐Bo Gu Chun‐Jian Zhao Yu‐Jie Fu 《Journal of separation science》2012,35(24):3600-3608
An ionic liquid‐based surfactant combined with microwave‐assisted extraction method, followed by RP‐HPLC‐diode array detection (DAD) with a core shell column, was successfully applied in extracting and quantifying four major phloroglucinols from Dryopteris fragrans. Eight ionic liquids with different cation and anion were investigated, and 1‐octyl‐3‐methylimidazolium bromide presented the best relative extraction efficiency for four phloroglucinols. The optimum conditions of this method were as follows: ionic liquid concentration 0.75 M, liquid/solid ratio 12:1 mL/g, extraction time 7 min, extraction temperature 50°C, and irradiation power 600 W. The quality analytical parameters of the method were obtained based on the linearity, precision, accuracy, detection, and quantification limits. The recoveries were between 96.90 and 103.5% with standard deviations not higher than 4.7%. Compared with ionic liquid‐based heat reflux extraction, ultrasonic‐assisted extraction, negative‐pressure cavitation extraction, and conventional microwave‐assisted extraction, the relative extraction efficiencies of the proposed method for four phloroglucinols increased 1.5–40.4%. The method was successfully applied for the quantification of four major phloroglucinols from D. fragrans. All these results suggest that the developed method represents an excellent alternative for the extraction and quantification of phloroglucinols in other plant materials. 相似文献
8.
The zeolitic imidazolate framework‐8 (ZIF‐8) was successfully synthesized using ionic liquids as structure‐directing agent under microwave irradiation. Ionic liquids are green solvents with low vapour pressure and good thermal stability. They are appropriate templates for microporous materials and ideal microwave absorbers. The microwave‐assisted ionothermal synthesis applied in this paper was expected to be a promising method for the preparation of microporous materials. Results showed that the as‐synthesized samples (300–500 nm in diameter) could be synthesized in a short time (60 min) and possessed regular morphology, stable structure and high thermal stability (up to 720°C in argon atmosphere). Nitrogen adsorption‐desorption test illustrated that samples produced by microwave heating had a higher surface area. Carbon dioxide adsorption test indicated that the samples synthesized by microwave heating had better carbon dioxide adsorption ability than those by conventional heating. 相似文献
9.
Dr. Da‐Young Sung Dr. Jayavant L. Gunjakar Dr. Tae Woo Kim Dr. In Young Kim Yu Ri Lee Prof. Seong‐Ju Hwang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7109-7117
A new prompt room temperature synthetic route to 2D nanostructured metal oxide–graphene‐hybrid electrode materials can be developed by the application of colloidal reduced graphene oxide (RGO) nanosheets as an efficient reaction accelerator for the synthesis of δ‐MnO2 2D nanoplates. Whereas the synthesis of the 2D nanostructured δ‐MnO2 at room temperature requires treating divalent manganese compounds with persulfate ions for at least 24 h, the addition of RGO nanosheet causes a dramatic shortening of synthesis time to 1 h, underscoring its effectiveness for the promotion of the formation of 2D nanostructured metal oxide. To the best of our knowledge, this is the first example of the accelerated synthesis of 2D nanostructured hybrid material induced by the RGO nanosheets. The observed acceleration of nanoplate formation upon the addition of RGO nanosheets is attributable to the enhancement of the oxidizing power of persulfate ions, the increase of the solubility of precursor MnCO3, and the promoted crystal growth of δ‐MnO2 2D nanoplates. The resulting hybridization between RGO nanosheets and δ‐MnO2 nanoplates is quite powerful not only in increasing the surface area of manganese oxide nanoplate but also in enhancing its electrochemical activity. Of prime importance is that the present δ‐MnO2–RGO nanocomposites show much superior electrode performance over most of 2D nanostructured manganate systems including a similar porous assembly of RGO and layered MnO2 nanosheets. This result underscores that the present RGO‐assisted solution‐based synthesis can provide a prompt and scalable method to produce nanostructured hybrid electrode materials. 相似文献
10.
Design of guanidinium ionic liquid based microwave‐assisted extraction for the efficient extraction of Praeruptorin A from Radix peucedani 下载免费PDF全文
Xueqin Ding Li Li Yuzhi Wang Jing Chen Yanhua Huang Kaijia Xu 《Journal of separation science》2014,37(23):3539-3547
A series of novel tetramethylguanidinium ionic liquids and hexaalkylguanidinium ionic liquids have been synthesized based on 1,1,3,3‐tetramethylguanidine. The structures of the ionic liquids were confirmed by 1H NMR spectroscopy and mass spectrometry. A green guanidinium ionic liquid based microwave‐assisted extraction method has been developed with these guanidinium ionic liquids for the effective extraction of Praeruptorin A from Radix peucedani. After extraction, reversed‐phase high‐performance liquid chromatography with UV detection was employed for the analysis of Praeruptorin A. Several significant operating parameters were systematically optimized by single‐factor and L9 (34) orthogonal array experiments. The amount of Praeruptorin A extracted by [1,1,3,3‐tetramethylguanidine]CH2CH(OH)COOH is the highest, reaching 11.05 ± 0.13 mg/g. Guanidinium ionic liquid based microwave‐assisted extraction presents unique advantages in Praeruptorin A extraction compared with guanidinium ionic liquid based maceration extraction, guanidinium ionic liquid based heat reflux extraction and guanidinium ionic liquid based ultrasound‐assisted extraction. The precision, stability, and repeatability of the process were investigated. The mechanisms of guanidinium ionic liquid based microwave‐assisted extraction were researched by scanning electron microscopy and IR spectroscopy. All the results show that guanidinium ionic liquid based microwave‐assisted extraction has a huge potential in the extraction of bioactive compounds from complex samples. 相似文献
11.
Xu Xu Zhuang Liu Xin Zhao Rui Su Yupu Zhang Jiayuan Shi Yajing Zhao Lijie Wu Qiang Ma Xin Zhou Hanqi Zhang Ziming Wang 《Journal of separation science》2013,36(3):585-592
A green and simple method, ionic liquid‐based microwave‐assisted surfactant‐improved dispersive liquid–liquid microextraction and derivatization was developed for the determination of aminoglycosides in milk samples. Nonionic surfactant Triton X‐100 and ionic liquid 1‐hexyl‐3‐methylimidazolium hexafluorophosphate were used as the disperser and extraction solvent, respectively. Extraction, preconcentration, and derivatization of aminoglycosides were carried out in a single step. Several experimental parameters, including type and volume of extraction solvent, type and concentration of surfactant, microwave power and irradiation time, concentration of derivatization reagent, and pH value and volume of buffer were investigated and optimized. Under the optimum experimental conditions, the linearities for determining the analytes were in the range 0.4–10.0 ng/mL for tobramycin, 1.0–25.0 ng/mL for neomycin, and 2.0–50.0 ng/mL for gentamicin, with the correlation coefficients ranging from 0.9991 to 0.9998. The LODs for the analytes were between 0.11 and 0.50 ng/mL. The present method was applied to the analysis of different milk samples, and the recoveries of aminoglycosides obtained were in the range 96.4–105.4% with the RSDs lower than 5.5%. The results showed that the present method was a rapid, convenient, and environmentally friendly method for the determination of aminoglycosides in milk samples. 相似文献
12.
《中国化学会会志》2017,64(10):1164-1171
A green biogenic, nontoxic, high‐yielding synthetic method is introduced for the synthesis of silver nanoparticles (AgNPs) using ionic‐liquid‐based, microwave‐assisted extraction (ILMAE) from Polygonum minus . The aqueous ionic liquid (1‐butyl‐3‐methylimidazolium chloride [BMIM]Cl)‐based plant extract was used as reducing agent to reduce silver ions to AgNPs. The synthesis of AgNPs was confirmed by UV–visible spectrophotometry. Fourier transforms infrared (FTIR) spectra showed that the plant bioactive compounds capped the AgNPs. The particle size and morphology of Ag NPs were characterized by dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM), respectively. Elemental analysis was carried out by energy‐dispersive X‐ray (EDX) spectroscopy. Photodegradation studies showed that the AgNPs degraded 98% of methylene blue in 12 min. 相似文献
13.
Biological organisms are produced from self-assembly of highly ordered functional units and are inherently complex and hierarchical, possessing macro-to-nanoscale features. It is a facile, low-cost and environmentally benign short-cut to artificial functional materials with unique multilevel structures and morphologies employing biological substances as platform for the self-assembly of various guest substrates. This review summarizes the recent advances in the fabrication of nanostructured materials with designed properties and functionalities by means of self-assembly of different guest substrates (such as metal oxide thin films, small molecules, polymers, biomacromolecules, nanoparticles, carbon nanotubes and colloidal spheres) on the surfaces of cellulose nanofibers of bulk natural cellulose substances. The combination of the specific chemical properties of the guest substrates and the unique physical features of the natural cellulose substances sheds new light on the design and syntheses of new functional nanomaterials. 相似文献
14.
液-液(油-水)界面合成是近几年发展起来的一种制备纳米材料的有效方法,具有温和、低廉、操作简便且不需要模板等特点。 液-液界面特殊的物理化学性质使其在制备纳米材料和薄膜方面拥有独特的优势。 本文主要就近几年应用液-液界面进行纳米材料的制备及应用研究进行了综述。 所制备的纳米材料包括金属单质、氧化物、硫族化物、聚合物、异质二聚体和金属有机框架材料等。 并特别对新发展的离子液体-水界面可控合成技术进行了评述。 最后,对液-液界面合成在纳米材料制备方面的优点、存在的问题和未来的发展进行了评述和展望。 相似文献
15.
Speciation analysis of mercury in sediments using ionic‐liquid‐based vortex‐assisted liquid–liquid microextraction combined with high‐performance liquid chromatography and cold vapor atomic fluorescence spectrometry 下载免费PDF全文
An improved novel method based on ionic liquid vortex‐assisted liquid–liquid microextraction has been developed for the extraction of methylmercury, ethylmercury and inorganic mercury in sediment samples prior to analysis by high‐performance liquid chromatography with cold vapor atomic fluorescence spectrometry. In this work, mercury species were firstly complexed with dithizone, and the complexes were extracted into 1‐hexyl‐3‐methylimidazolium hexafluorophosphate. Key factors that affect the extraction efficiency of mercury species, such as type and amount of ionic liquid and chelatants, extraction time, sample pH, salt effect and matrix effect were investigated. Under the optimum conditions, linearity was found in the concentration range from 0.1–70 ng/g. Limits of detection ranged from 0.037–0.061 ng/g. Reproducibility and recoveries were assessed by extracting a series of six independent sediment samples that were spiked with different concentration levels. Finally, the proposed method was successfully applied in analysis of real sediment samples. In this work, ionic liquids vortex‐assisted liquid–liquid microextraction was for the first time used for the extraction of mercury species in sediment samples. The proposed method was proved to be much simpler and more rapid, as well as more environmentally friendly and efficient compared with the previous methods. 相似文献
16.
The synthesis of polypyrrole (PPy)/AgCl nanocomposites with their size ranging around 70–100 nm are achieved by using magnetic ionic liquid as the oxidant in the interface polymerization system. The interface polymerization leads to the formation of uniform and unaggregated nanocomposites with a relatively narrow size distribution confined to submicrometer‐sized domains. The morphology and structure of the nanocomposites are characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X‐ray diffraction (XRD). The potential application of PPy/AgCl nanocomposites as a H2O2 biosensor is also reported. Copyright © 2010 John Wiley & Sons, Ltd. Erratum: Magnetic ionic liquid‐assisted synthesis of polypyrrole/AgCl nanocomposites 相似文献
17.
Applying Mechanochemistry for Bottom‐Up Synthesis and Host–Guest Surface Modification of Semiconducting Nanocrystals: A Case of Water‐Soluble β‐Cyclodextrin‐Coated Zinc Oxide 下载免费PDF全文
Piotr Krupiński Arkadiusz Kornowicz Dr. Kamil Sokołowski Anna M. Cieślak Prof. Janusz Lewiński 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7817-7823
Mechanochemistry has recently emerged as an environmentally friendly solventless synthesis method enabling a variety of transformations including those impracticable in solution. However, its application in the synthesis of well‐defined nanomaterials remains very limited. Here, we report a new bottom‐up mechanochemical strategy to rapid mild‐conditions synthesis of organic ligand‐coated ZnO nanocrystals (NCs) and their further host–guest modification with β‐cyclodextrin (β‐CD) leading to water‐soluble amide‐β‐CD‐coated ZnO NCs. The transformations can be achieved by either one‐pot sequential or one‐step three‐component process. The developed bottom‐up methodology is based on employing oxo‐zinc benzamidate, [Zn4(μ4‐O)(NHOCPh)6], as a predesigned molecular precursor undergoing mild solid‐state transformation to ZnO NCs in the presence of water in a rapid, clean and sustainable process. 相似文献
18.
Jiao Jiao Qing‐Yan Gai Wei Wang Meng Luo Chun‐Jian Zhao Yu‐Jie Fu Wei Ma 《Journal of separation science》2013,36(23):3799-3806
A rapid, green and effective miniaturized sample preparation technique, ionic‐liquid‐assisted microwave distillation coupled with headspace single‐drop microextraction was developed for the extraction of essential oil from dried Dryopteris fragrans. 1‐Ethyl‐3‐methylimidazolium acetate was the optimal ionic liquid as the destruction agent of plant cell walls and microwave absorption was medium. n‐Heptadecane (2.0 μL) was adopted as the suspended microdrop solvent in the headspace for the extraction and concentration of essential oil. The optimal parameters of the proposed method were an irradiation power of 300 W, sample mass of 0.9 g, mass ratio of ionic liquids to sample of 2.8, extraction temperature of 79°C, and extraction time of 3.6 min. In comparison to the previous reports, the proposed technique could equally monitor all the essential oil components with no significant differences in a simple way, which was more rapid and required a much lower amount of sample. 相似文献
19.
Krishnendu B. Sahu Arindam Maity Shyamal Mondal Rupankar Paira Pritam Saha Subhendu Naskar Abhijit Hazra Sukdeb Banerjee Nirup B. Mondal 《Journal of heterocyclic chemistry》2013,50(Z1):E148-E155
A basic alumina‐supported microwave assisted simple methodology has been developed for the synthesis of aryl‐heteroaryl methanes (benzylated quinolones) via transition metal catalyzed cross‐coupling reaction of halo substituted polynuclear oxa‐aza quinolones with benzyl indium, an organometallic reagent easily derived from commercially available benzyl bromide. 相似文献