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.
Christina H. M. Tsang,Ruilong Zhang,Wei Xiong,Davidraj Johnravindar,Puranjan Mishra,Jun Zhao
The escalating demand for plastics has necessitated advancements in plastic recycling technologies. This study examines the development of heterogeneous metal catalysts aimed at improving the hydrolysis performance of polyethylene terephthalate (PET), a commonly used plastic, and enhancing the conversion efficiency for the efficient production of terephthalic acid (TPA). A series of Mg-Al bimetallic oxide with varying Mg and Al ratios were synthesized and employed as catalysts for the hydrolysis of PET under various conditions, including reaction temperature (80°C–220°C), reaction time (10–300 min), and solvent ratio. Optimization of the process revealed that the optimal conditions for catalytic hydrolysis were achieved at 200°C, 300 min, using a Mg-Al-1 catalyst and a solvent ratio of 5:5 ethanol to water, resulting in a PET conversion efficiency of 95.6% and a TPA yield of 80.3%. Over 70% TPA yield could be generated after first hydrolysis without regeneration. Under hydrothermal conditions, polyethylene glycol instead of ethylene glycol was found after reaction, as identified by liquid chromatography–mass spectrometry (LC–MS). This study offers a sustainable and feasible pathway for TPA recovery from PET, contributing to the advancement of recycling technologies.
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