Fabrication of Fe3O4@PVA-Cu Nanocomposite and Its Application for Facile and Selective Oxidation of Alcohols

Ammonium metavanadate (NH4VO3): a highly efficient and eco-friendly catalyst for one-pot synthesis of pyridines and 1,4-dihydropyridines

In this study, we reported the ammonium metavanadate (NH₄VO₃) as an efficient, cost-effective, and mild catalyst for the synthesis of substituted pyridines via a one-pot pseudo four-component reaction. Furthermore, we investigated Hantzsch 1,4-dihydropyridines (1,4-DHPs) synthesis and oxidation of 1,4-DHPs to their corresponding pyridines. The present approach offers a rapid methodology for accessing various pyridines with broad functional group tolerance and good yields using NH₄VO₃ catalyst as a green catalyst.

Investigation on the Controllable Synthesis of Colorized and Magnetic Polystyrene Beads With Millimeter Size via In Situ Suspension Polymerization

A series of colorized and magnetic polystyrene/Fe₃O₄ (PS/Fe₃O₄) composite beads with millimeter size are successfully synthesized by introducing hydrophobic Fe₃O₄via in situ suspension polymerization of styrene for the first time. Effects of the hydrophobic Fe₃O₄ content, stirring speed, and surfactant dosage on the macromorphology and particle size of PS/Fe₃O₄ beads are systematically investigated to realize the controllable synthesis. Moreover, three kinds of hydrophobic pigments are also employed to synthesize colorized polystyrene, which demonstrates the versatility, simplicity, and wide applicability of the proposed method. Scanning electron microscopy (SEM) and element mapping (EM) images demonstrated that the hydrophobic Fe₃O₄ is well dispersed in the polystyrene matrix. Thermogravimetric analysis (TGA) shows that the resultant PS/Fe₃O₄ beads possess a better thermal stability than neat PS. PS/Fe₃O₄ beads have a promising application in the fields of colorized extruded PS board, colorized expanded PS foam particle, and board.