Synthesis and characterization of MWCNTs/Co1−xZnxFe2O4 magnetic nanocomposites and their use in hydrogels

▶ MWCNTs/Co1−xZnxFe2O4 magnetic nanocomposites were synthesized via a one-step solvothermal approach. And the MWCNTs/Co1−xZnxFe2O4 magnetic nanocomposite functionalized PNIPAAm gels were prepared and expected to be used as a light-driven and magnetic controlled switch in microreactors. Results indicated that cobalt, zinc and iron cations added to the solution were compactly attached by electrostatic attraction on the surface of pretreated MWCNTs, and Co1−xZnxFe2O4 nanocrystallites were formed gradually. The saturation magnetization of the magnetic nanocomposites reached a maximum value of 57.5 emu g−1 for x = 0.5. Furthermore, these nanocomposites display a high magnetic sensitivity and have a high saturation magnetization. And the PNIPAAm/MWCNTs/Co1−xZnxFe2O4 hydrogels had been prepared as a prototype of device to show the potential application of the nanocomposites for the first time. We believe it will be of interest to the journal's readers, especially in the fields of the technology of magnetic composites.