INSITU SYNTHESIS OF FERRITES IN LIGNOCELLULOSICS

In situ synthesis of iron oxide particles in O-(carboxymethyl)ated cellulose fibers and sulfonated wood fibers was performed by careful oxidation of ferrous hydroxide precipitated by alkali from the ferrous ion-exchanged form of the matrix. This ''biomimetic'' chemistry yielded magnetic fibers containing small ferrite (Fe3O4) particles of approximately 10 nm in size. Magnetic hysteresis-loop measurements showed that the material, in the form of a thin parchment-like film, is superparamagnetic, that is, it possesses no remanent magnetization. The process described herein could be practiced with a wide range of natural biopolymers in order to obtain magnetically responsive materials suitable for such biotechnological applications as magnetic separations.