Alumina fillers having different morphologies were used for reinforcement of PMMA-based composite materials. The employed fillers had the same chemical composition but morphologically were spherical nanoparticles, whiskers and an electrospun product that was composed of micro-sized mostly spherical particles and nanofibers. The electrospun product was obtained from aluminum chloride hydroxide/PVA/water solution. All fillers were added without surface treatment and mechanical characteristics of obtained composites were determined using dynamic mechanical analysis (DMA) and nanoindentation. From the nanoindentation results, the reduced elastic modulus for the obtained specimens using 3 wt.% of electrospun product was 134% of the one obtained with the polymer alone and the hardness was improved to 157.8% compared to the polymer without any additive. DMA shows that the storage modulus at room temperature was twice that of the polymer alone.

Pastes containing CPP-ACP or CPP-ACFP showed potential to remineralize enamel surface lesions.

Hybrid composite panels of Wood-Plastic Composites (WPC) consisting of wood and poly (methyl methacrylate) (PMMA) were reinforced with alumina particles and made by "hot pressing" method. Alumina-based particles were made by sol-gel technique. The particles were characterized by the X-ray diffraction (XRD). The resulting alumina particles were modified with (3mercaptopropyl) trimethoxysilane (MPTMS), in order to obtain better mechanical properties of the composite relative to the composite with unmodified alumina particles. The aim of this work was to study the influence of composite structure and the moisture absorption on bending and the impact properties of the hybrid composite. The bending and impact tests revealed that modulus of elasticity and absorbed energy of deformation increased with modification of alumina and slightly decrease after moisture absorption.

Adsorption of anthraquinone dye Acid Blue 111 by alumina-iron oxide doped particles prepared by sol-gel method from aqueous solutions was studied. The adsorbent morphology was revealed by FESEM and the crystallographic phase is analyzed by the XRD technique. The effect of adsorbate and adsorbent concentrations, pH value, type of adsorbent and thermodynamic parameters on dye removal by adsorption was studied. The change of dye concentration during the adsorbtion was followed using the UV-Visible spectrophotometer. The change of the adsorbent surface before and after dye removal was observed using the Fourier Transformation-infrared spectroscopy (FT-IR). The adsorption kinetics is in accordance with the pseudo-second-order kinetics model. The Langmuir and Freundlich adsorption isotherm models were used to describe the adsorption process. The thermodynamic study of dye adsorption proves the process is spontaneous with exothermic nature.

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