Fe3O4 magnetic nanoparticles (MNPs) were modified with (3‐aminopropyl)triethoxysilane through silanization. An atom transfer radical polymerization‐initiating site immobilized onto amine‐functionalized Fe3O4 MNPs. The surface‐initiated atom transfer radical polymerization of 4‐vinylpyridine was then performed in the presence of Fe3O4–SiO2–Br nanoparticles, which led to the formation of Fe3O4–SiO2–P4VP [P4VP=poly(4‐vinylpyridine)] hybrid microgels cross‐linked with Fe3O4 MNPs. Our approach uses polymer microgels as templates for the synthesis of nickel nanoparticles (NiNPs). The tunable properties of synthesized NiNPs@Fe3O4–SiO2–P4VP pH‐sensitive microgels were used in the catalytic reduction of aliphatic and aromatic nitriles. Moreover, the catalytic activity of metal nanocomposites that can be modulated by the volume transition of microgel structures with changing pH has been evaluated. TEM, X‐ray photoelectron spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, XRD, UV/Vis spectroscopy, and FTIR spectroscopy were used to characterize the resultant catalyst.

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The preparation of Ni@Pd core-shell nanoparticles immobilized on yolk-shell Fe 3 O 4 @polyaniline composites is reported. Fe 3 O 4 nanoclusters were first synthesized through the solvothermal method and then the SiO 2 shell was coated on the Fe 3 O 4 surface via a sol-gel process. To prepare Fe 3 O 4 @SiO 2 @polyaniline composites, polyvinylpyrrolidone was first grafted on to the surface of Fe 3 O 4 @SiO 2 composites and subsequently polymerization of aniline was carried out via an ultrasound-assisted in situ surface polymerization method. Selective etching of the middle SiO 2 layer was then accomplished to obtain the yolk-shell Fe 3 O 4 @polyaniline composites. The approach uses polyaniline (PANI) conductive polymer as a template for the synthesis of Ni@Pd core-shell nanoparticles. The catalytic activity of the synthesized yolk-shell Fe 3 O 4 @PANI/Ni@Pd composite was investigated in the reduction of o-nitroaniline to benzenediamine by NaBH 4 , which exhibited conversion of 99% in 3 min with a very low content of the catalyst. Transmission electron microscopy, X-ray photoelectron spectroscopy, TGA, X-ray diffraction, UV-visible, scanning electron microscopy, X-ray energy dispersion spectroscopy and FT-IR were employed to characterize the synthesized nanocatalyst.

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The main objective of the current work is to develop a luminol based chemiluminescence (CL) system with the help of reactive functional polymer of azothiacalix[4]arene-modified carboxymethyl cellulose (ACCMC) for trace...