Síntesis y caracterización de un material polimérico híbrido magnético de nanopartículas de óxido de hierro en una matriz de polivinil butiral

Abstract

A Polymeric Magnetic Hybrid Material (PMHM), consisting of iron-oxide nanoparticles synthesized in-situ in a Polymer Matrix of Polyvinyl Butyral (PVB), was developed in two stages. First, a precursor film hybrid material (Fe(II)-PVB) was obtained. In the second stage, Fe(II)-PVB was treated with H 2 O 2 under alkaline conditions to obtain the PMHM. Characterization by XRD shows that the crystalline structure of iron oxide into PMHM corresponds to goethite, and to maghemite or magnetite phases. FTIR-spectroscopy reveal that the PVB-matrix preserves its chemical structure into the PMHM. HRTEM-images show that iron oxide nanoparticles (~5 nm) with sphere-like morphology are embedded into PVB-matrix; and diagrams of magnetization versus temperature, show that embedded nanoparticles have a superparamagnetic-like behavior. Finally, magnetorheological results show that mechanical properties of PMHM can be modified under the application of an external magnetic field, showing that it is a good alternative to carry out functions as actuator or sensor in electronic or mechatronic devices.

The effect of iron oxide nanoparticles on the mechanical relaxation of magnetic polymer hybrid films composed of a polystyrene matrix, a fractional calculus approach

“…In the X‐ray diffraction pattern obtained for the Fe(II)‐PS sample, it was corroborated by the absence of Fe crystals, confirming that the Fe ions were solvated by segment chains of PS matrix. However, the diffractogram of Fe(II)‐PS sample also shows a peak at 27°; this peak was related to goethite phase (α‐FeOOH) due to formation of iron oxyhydroxides . These results suggest that the FeCl 2 ·4H 2 O salt was dissolved into PS matrix.…”

“…The presence of these aggregates has been reported and associated to the effect of the aqueous ambient and the reaction temperature on the ions of the precursor salt, FeCl 2 ·4H 2 O. Figure (b) shows the crystalline structure of the IONPs, presenting planes with interplanar distances of 0.2515 nm and 0.2957 nm, which correspond to planes (311) and (220), respectively; they are associated with a crystalline structure identified as maghemite …”

“…From the PS matrix diffractogram, two scattered peaks associated to long‐range order (without crystallization) are observed. They are produced due to the biorientation generated by the film's manufacturing process . These scattered peaks are characteristic of amorphous polymers diffractograms.…”

“…Magnetic polymer hybrid films (MPHFs), composed of iron oxide nanoparticles (IONPs) and polymer matrices, are of great interest to carry out functions as actuators or sensors in electronic or mechatronic devices . However, structural relaxations of the polymeric matrix must be studied to optimize the potential applications of these MPHFs.…”

“…The addition of IONPs into a PS matrix produces a synergy among them, such that the obtained MPHF responds to an external magnetic field with fast reaction and contactless control . Additional applications could also be obtained for MPHFs considering that the magnetic properties of IONPs are very important due to their potential integration into a broad range of technological applications, extending from magnetic fluids, catalysis, ultrahigh‐density magnetic storage media, biotechnology and biomedicine, and magnetic resonance imaging …”