- 标题
- 摘要
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- 实验方案
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Fast dispersive liquid–liquid microextraction based on magnetic retrieval of in situ formed an ionic liquid for the preconcentration and determination of benzophenone-type UV filters from environmental water samples
摘要： This work concerns the development of a novel and rapid in situ dispersive liquid–liquid microextraction method for magnetic retrieval of ionic liquid as a new approach for the separation of benzophenone type (BP-type) UV filters via quantification using UPLC with PDA detection. The analytes determined in this study were a group of three benzophenones: 2,4-dihydroxybenzophenone (BP1), 2,2′,4,4′-tetrahydroxybenzophenone (BP2) and 2-hydroxy-4-metoxybenzophenone (BP3). The hydrophilic ionic liquid found suitable for use as an extraction solvent of the targeted analytes was didecyldimethylammonium chlorate (DDAC). An anion exchanger, NaClO4 was added to promote a metathesis reaction and in situ formed the IL, [DDA][ClO4]. The experimental parameters such as the concentration of IL, the molar ratio of DDAC to NaClO4, amount of iron oxide added and volume of water sample were investigated and optimised using a step-by-step optimisation process. The optimum experimental parameters were as follows: 30 mL of sample volume, 1% concentration of DDAC, the molar ratio of DDAC to NaClO4—1:2, and 5 mg of Fe3O4 magnetic nanoparticles. The proposed extraction method is simple and requires no more than 5 min. The detection limit (LOD) obtained for target analytes ranged from 12.320.0 ng L?1, while the correlation coefficient (r2) was from 0.9995 to 0.9999. Finally, the developed method was successfully applied to the determination of BP-type UV filters in environmental water samples, and satisfactory results were obtained.
关键词： In situ MR IL-DLLME,Ionic liquid,Benzophenones,BP-type UV filters,Magnetic nanoparticles
更新于2025-09-09 09:28:46
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A liquid crystal based method for detection of urease activity and heavy metal ions by using stimulus-responsive surfactant-encapsulated phosphotungstate clusters
摘要： A liquid crystal (LC) based method is described for the sensitive determination of the activity of urease and of heavy metal ions which acts as inhibitors. Stimulus-responsive surfactant-encapsulated phosphotungstate clusters (SECs) were fabricated and deposited onto octadecyltrichlorosilane-coated glass. A copper TEM grid filled with LCs was placed on the substrate to construct the LC optical cell. Upon addition of water to the LC interface, the optical appearance of LCs on the glass undergoes a bright-to-dark shift due to an orientational transition of the LCs from a planar to a homeotropic state. However, the LCs display a bright appearance if they are pretreated with an aqueous solution containing urea and urease. This is caused by the disassemby of the SECs from the glass surface due to an increase of the pH value that is induced by the enzymatic hydrolysis of urea by urease. The method is highly sensitive and can detect urease activities as low as 0.03 mU/mL. It can also be applied to the determination of heavy metal ions which exert an inhibitory effect on the activity of urease. For example, Cu(II) can be quantified via urease inhibition in 1 nM concentration.
关键词： Ionic liquid,Stimulus-responsive material,Surfactant,Sensor layer,Polyoxometalates,Urease,Nanocomposites,Ionic self-assembly,Liquid crystal
更新于2025-09-04 15:30:14
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Improved photocatalytic performance of flower-like BiOBr/BiOCl heterojuctions prepared by an ionic liquid assisted one-step hydrothermal method
摘要： Construction of heterojuctions is a promising and solid strategy to tune the photocatalytic performance of BiOCl. In this work, flower-like BiOBr/BiOCl heterojuctions (IL-BiOCl) was in-situ prepared by N-ethylpyridinium bromide ([BPy]Br) assisted one-step hydrothermal method. The samples were studied by a serials method. The results exhibit that [BPy]Br promotes the specific surface area and the separation rate of photoinduced carriers. Energy dispersive spectrometer (EDS) and high resolution transmission electron microscopy (HRTEM) results firmly reveal that BiOBr/BiOCl heterojuctions were successfully constructed. [BPy]Br provides Br source for BiOBr and influences the shape of the IL-BiOCl. Photocatalytic activity of the samples were evaluated, the results reveal that IL-BiOCl possesses higher photocatalytic activity than BiOCl toward decomposition of rhodamine B (RhB) under simulated sunlight irradiation.
关键词： Semiconductors,surfaces,crystal growth,ionic liquid,BiOCl
更新于2025-09-04 15:30:14
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Flower-like ZnO/ionic liquid composites: structure, morphology, and photocatalytic activity
摘要： Two ionic liquids (ILs) with different alkyl chains, 1-butyl-3-methylimidazolium chloride (BMI.Cl) and 1-hexadecyl-3-methylimidazolium chloride (C16MI.Cl), were incorporated into ZnO particles using the microwave-assisted hydrothermal (MAH) method. The morphology and microstructure of ZnO and ZnO/IL composites were characterized along with their photocatalytic effect for dye degradation. While the incorporation of ILs into the ZnO particles did not alter their morphology, it converted the shallow defects into deep defects. These changes improved Rhodamine B (RhB) photodegradation efficiency. The dye degradation reached 62% when ZnO/C1640 was used, whereas it reached 30% when pure ZnO was used, during the same time interval.
关键词： ZnO,Ionic liquid,Photocatalysis,Optical properties
更新于2025-09-04 15:30:14
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[ACS Symposium Series] Raman Spectroscopy in the Undergraduate Curriculum Volume 1305 || Integration of Raman Spectroscopy in Undergraduate Instruction and Research at Pace University
摘要： The integration of Raman spectroscopy into undergraduate instruction and research at Pace University is discussed in this chapter. This includes the introduction of the principle of Raman instrumentation, first by theory through the use of Gaussian calculations and interpretation of readily available spectra and then using the instrument after the acquisition of a B&W Tek Miniram in 2012. The availability of the instrument allows students to expand their research in sol-gel, ionic liquid, pharmaceuticals, and biodiesel. The development of simple experiments to incorporate into laboratory classes and side-by-side comparisons of experimental results and theoretical calculations are also presented. The challenges and successes of having this instrument in our teaching facility are also described.
关键词： undergraduate instruction,ionic liquid,research,Raman spectroscopy,pharmaceuticals,sol-gel,B&W Tek Miniram,biodiesel,Pace University
更新于2025-09-04 15:30:14
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Viscoelastic change of block copolymer ion gels in a photo-switchable azobenzene ionic liquid triggered by light
摘要： A photo-switchable ionic liquid solvent bearing an azobenzene moiety induced a viscoelastic change of block copolymer ion gels by light. ABA triblock copolymers having poly(phenethyl methacrylate) and poly(benzyl methacrylate) as A blocks exhibited opposite photo-induced rheological responses although they had only a tiny structural difference in the alkyl chain length.
关键词： block copolymer,ion gels,light,viscoelastic change,ionic liquid,azobenzene,photo-switchable
更新于2025-09-04 15:30:14