Preparation and Characterization of Algal Polysaccharides/Magnetite Microparticles Composite Films

Composites of magnetic particles in a polymeric matrix have received increasing interest due to their capacity to respond to external magnetic or electromagnetic fields. Algal polysaccharides such as agar are used extensively as gel-forming agents, thickeners, and stabilizers due to their low cost and high degree of biocompatibility and biodegradability. This study is focused on the preparation and characterization of algal polysaccharides-carbonyl iron composite films. The samples were analyzed using the photothermal radiometry (PTR) technique in the back-propagation emission configuration performing a modulation frequency scan. The amplitude and phase of the PTR experimental data were fitted simultaneously using a one-layer thermal-wave model considering homogeneous optical and thermal properties. The results indicate a systematic increase of the thermal diffusivity and optical absorption coefficient when the magnetic particle content increases. Scanning electron microscopy surface morphology of the agar/carbonyl iron composite indicates that a homogeneous distribution of particles can be obtained with the reported procedure and also provides evidence of agglomeration at high concentrations.