Magnetic studies of ferrofluid-modified spruce sawdust
نویسندگان
چکیده
Spruce sawdust (lignocellulose material) was magnetically modified after contact with a water-based magnetic fluid containing maghemite nanoparticles. This procedure allows one to use the prepared material as a new magnetic affinity adsorbent in magnetic separation techniques. The magnetic sawdust was investigated by means of electron spin resonance spectroscopy and conventional magnetic methods over the temperature range 4–300 K. The experimental results clearly show that the magnetic behaviour of the sample is determined by two distinct magnetic contributions. One of them is connected to the presence of isolated single domain maghemite nanoparticles of ∼11 nm in diameter, which exhibit superparamagnetic behaviour at T > 280 K. The other one is related to the presence of agglomerates of particles coupled by magnetic dipolar interactions.
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