Magnetic and spectroscopic properties of Polyacrylamide-CoFe2O4 magnetic hydrogel

This study investigates synthesis and characterization of polyacrylamide (PAAm) hydrogels containing ferromagnetic CoFe2O4 nanoparticles. Structural, electrical, and magnetic characterization of the gels have been performed with X-ray powder diffractometry, Scanning electron microscopy, DC conductivity, magnetization and fluorescence spectroscopy techniques. Fluorescence and electrical measurements show that nanoparticles have trapped in the gel so they cannot move through the gel even if the gel is swollen and the voltage is applied. Pyranine molecules diffuse easily through the gel due to the presence of ferromagnetic nanoparticles. As number of diffused pyranine molecules increases current densities of the magnetic hydrogel increase. Magnetization measurements reveal that CoFe2O4 nanoparticles do not diffuse out of the gel during swelling. As a result, total magnetization of the gel do not change as volume of the gel increases.

► Polyacrylamide (PAAm) hydrogels containing magnetic CoFe2O4 nanoparticles (NPs) have been synthesized.
► Pyranine (POH) molecules were used as fluoroprobe to investigate interaction of NPs with polymer strands.
► CoFe2O4 NPs have trapped in the gel so that it cannot move through the gel even the gel is swollen.
► CoFe2O4 NPs have superparamagnetic behavior.
► These features make the gel very suitable for applications like magnetic adsorbents.