Magnetic Hydrogels: Magnetic and Mechanical Measurements

Several species of magntic hydrogels (ferrogels) are prepared, and their magnetic and magnetoelastic properties are examined. Three substance are used as the bases: agarose, polyacrylamide and Pluronic. All the gel matrices are filled with the same nanopowder: iron particles with the mean size about 30 nm. The "critical" concentrations of the magnetic phase, above which the normal gel networks cease to form, are estimated. The magnetization curves of the samples are measured at different stages of de-swelling, and their elastic properties are tested under a uniform magnetic field. The results indicate field-induced rigidity of magnetic hydrogels Magnetic hydrogels (also known as ferrogels) are quite new smart nanocomposites with a wide prospect in applications [1-11]. In particular, these soft magnetic materials are intended to be used as humidity and temperature sensors and actuators of many kinds in microfluidics and medicine. Due to that, their investigation is an issue of progressively growing interest for chemists, physicists and engineers.