Metal sulfide is often utilized as a catalyzed material to form colorimetric response system for some heavy metal detection. While the aggregation effect and conventional morphology limited the catalyzed efficiency. Herein, a robust method based on morphology adjustment was proposed to improve the dispersibility and catalytic performance of CuS. The results demonstrated when the solvent ratio of ethylene glycol and dimethyl sulfoxide arrived at 3:1, it displayed an optimal structure which is like a patulous flower. Meanwhile, an optimal surface binding energy (ΔE) of 120.1 kcal/mol was obtained via theoretical calculation model. The flower-like structure caused a 2-fold increase in the catalytic level. Subsequently, the CuS was employed to make colorimetric detection of Cr(VI) in water. The assay results exhibited a linear range of the Cr(VI) from 60 to 340 nM, the limit of detection was 1.07 nM. In the practical tests for Qianhu lake water, the spiked recoveries were 93.6% and 104% with the RSD of 4.71% and 3.08%. Therefore, this CuS-based colorimetric method possesses a satisfactory application prospect for the Cr(VI) determination in water.Keywords:CuS;morphology adjustment;solvent ratio;Cr(VI);colorimetric detection
Fiber membranes with high specific surface area can be produced when using electrospinning technology combined with amphiphilic block polymers. Due to the solubility difference between the two segments of amphiphilic block polymers, it is easy to be self-assembly in solvents, which affects the morphology of the spinning fiber and the surface properties of the membrane. In this work, the relationship between the self-assembly of the amphiphilic block polymer and the morphology of the spinning fiber and the wetting performance of the spinning membrane was explored. Membrane is produced by electrospinning amphiphilic block copolymer PS-b-PHEMA (polystyrene-block-poly(2-hydroxyethyl methacrylate) by using co-solvent system. PS-b-PHEMA with controlled molecular weight (Mw) and polymer dispersity index (PDI) was synthesized via atom transfer radical polymerization (ATRP) and characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The electrospun membrane have both super-hydrophobic and super-hydrophilic by adjusting the ratio of mixed solvents, demonstrating that the wetting performance of the fiber membrane mainly depends on the shell structure of the self-assembly micelles.
MnFe2O4magnetic nanoparticles have shown broad application prospects in the field of tumor diagnosis and treatment; however, precise particle size regulation within the 100–200 nm range, as well as the synergistic integration of physical and medical functionalities, remains challenging. As a commonly used method for synthesizing MnFe2O4nanoparticles, the solvothermal method has been proven to enable the regulation of the particle size of products, particularly its ability to utilize the viscosity of solvents as a method for particle size regulation. Therefore, this work investigates the influence of the diethylene glycol (DEG) to ethylene glycol (EG) ratio on particle size regulation in solvothermal synthesis of MnFe2O4nanoparticles, and constructs MnFe2O4@PB nanocomposite materials. The results demonstrate that with the DEG ratio increasing from 0 to 80% in a DEG:EG mixed solvent system, the average particle size of MnFe2O4nanoparticles can be reduced from 266 nm to 105 nm. The MPB4.5 sample (MnFe2O4:PB molar ratio = 5:4.5 in the MnFe2O4@PB nanostructure) exhibits an optimal photothermal heating effect and good photothermal stability, demonstrating potential as a photothermal therapeutic agent. The resultant MnFe2O4@PB system provides a strategy for precise particle size regulation and functional integration for photothermal therapy of tumors with magnetic targeting potential.
To enhance the selective fructose dehydration to 5-hydroxymethylfurfural (HMF), an efficient dehydration of fructose to 5-HMF in H 2 O-MIBK- pressured CO 2 in 20 min at 200 °C with a better product yield of 85.6% and 89.1% product selectivity was achieved. The high activity attributed to the combination of the weak acidity by CO 2 dissolved in the water and the efficient separation of fructose with 5-HMF in this H 2 O-MIBK two-phase system. The possible reaction mechanism is discussed. It was found that the solvents ratio was the one of key factors determining the yield of target products. Compared to the related reported results in the reaction, this process characterized of more favorable product yield and higher selectivity, it can be considered as a potential technique for the scale-up production of 5-HMF from fructose.