Magnetic iron oxide (maghemite, Fe 3 O 4 ) particles were encapsulated with polyester resin. The resulting magnetic powders were characterized by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fritsch particle sizer, scanning electron microscopy (SEM), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM) measurements. FTIR and XRD confirmed the presence of iron oxide in polymer phase. The TGA and DSC measurements indicated the magnetic polymer particles have more than 50% iron oxide content and high thermal stability. SEM revealed that all maghemite particles were embedded in the polymer phase. The size distribution analysis of prepared magnetic particles has shown that the mean diameter of the bare iron oxide particles slightly increased with encapsulation. According to our magnetometry data, shape of the loops evidences the ferromagnetic character of the material and no evidence of superparamagnetism was seen.
An organic inorganic hybrid nanocomposite of poly(2 acrylamido 2 methyl 1 propane sul fonic acid sodium salt) and Al 2 O 3 with nano alumina particles was synthesized in two steps. Firstly, the sur face of nano alumina particles was modified by 3 methacryloxy propyl trimethoxysilane as a coupling agent by sol gel method. Secondly, the surface modified nano alumina particles were grafted onto the poly(2 acry lamido 2 methyl propane sulfonic acid sodium salt) by free radical polymerization. The spectral (FTIR spectroscopy) and thermal (TGA) methods, verified the participation of coupling agent, polymer and alumi num oxide (alumina) into the hybrid structure. Introduction of silanol groups into the alumina particles leads to a better distribution of particles into the polymeric matrix. The results also showed four steps of weight loss for the hybrid nanocomposite, which includes about 80% weight loss until 700°C and 20% of char yield, which is due to presence of alumina, silica and sodium oxide in hybrid nanocomposite. SEM and TEM stud ies confirmed that the nano alumina particles have been spherical and homogeneously dispersed throughout the sample with dimensions in the range of nanosizes inside the nanocomposite sample containing 5 wt % of Al 2 O 3 . The analysis of thermo mechanical properties of homopolymer and its nanocomposite revealed the shift in storage modulus and tanδ peaks that was attributed to morphological changes in the nanocomposites due to the amount of inorganic nano particles and their distribution in polymer matrix. The adsorption behavior showed that hybrid nanocomposites have ability for interaction with heavy metal ions by means of adsorption through interaction between the oppositely charged functionalities and metal ions. However, it was found that the adsorption efficiency of the hybrid nanocomposite is much better than that of its pure polymer.
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