Clays and clay minerals are common natural materials, the unique properties of which have attracted the interest of the industry, especially because these materials are easily available, cheap, and non-toxic. Clays and clay minerals are widely used in many applications, such as in ceramic production, in the clarification of liquids, pollutant adsorbers, filler in composites and nanocomposites, soil amendments, in pharmacy, etc. This review assesses the development in the area of clay application in nanocomposites and ceramics. The first part of this study covers polymer/clay nanocomposites. Topics of interest include nanofiller sources for polymer nanocomposites, the possible ways of clay modification, polymer/clay nanocomposite classification and their processing, and polymer matrix overview with possible enhancement of nanocomposite properties. Some of the applications have already been commercialized. Approximately 80% of the polymer/clay nanocomposites are destined for the automotive, aeronautical, and packaging industries. The second part of this study describes ceramic materials with a focus on silicate ceramics. Talc and kaolinite represent the main natural raw materials for traditional ceramic applications. Less traditional cordierite, steatite, and forsterite could offer property enhancement and seem to be useful in electronics, electrical engineering, catalysts, solar thermal storage, or medical applications.

The alumina and zirconia surfaces were pretreated with chemical etching using alkaline mixtures of ammonia, hydrogen peroxide and sodium hydroxide, and followed with application of the powder layer of Ca-deficient hydroxyapatite (CDH). The influence of etching bath conditions time and concentration on surface development, chemical composition and morphology of medicinal ceramic powders were studied. The following analyses were performed: morphology (scanning electron microscopy), phase composition (X-ray diffraction analysis), changes in binding interactions and chemical composition (FT-Infrared and Energy dispersive spectroscopies). Both types of etchants did not expose the original phase composition changes or newly created phases for both types of ceramics. Subsequent decoration of the surface with hydroxyapatite revealed differences in the morphological appearance of the layer on both ceramic surfaces. The treated zirconia surface accepted CDH as a flowing layer on the surface, while the alumina was decorated with individual CDH aggregates. The goal of this study was to focus further on the ceramic fillers for polymer-ceramic composites used as a biomaterial in dental prosthetics.

Direct foaming using H₂O₂ solution was successfully applied to the preparation of cordierite ceramic foams. Cordierite ceramics were synthesized especially from the natural materials: kaolinite, talc and vermiculite, supplemented with Al₂O₃. Ag nanoparticles were prepared by green method from plant extract and after all decorated on ceramic materials. The presence of Ag nanoparticles in cordierite ceramic materials was confirmed by XRD and SEM analysis.

The zinc acetate dihydrate and anhydrous zinc chloride were used as precursors for the sonochemical preparation of the zinc oxide/vermiculite and organically modified zinc oxide/vermiculite_chlorhexidine nanocomposite materials. The nanocomposites were mechanically processed via a high-energy ball milling for 30 min at 300 rpm using two types of atmospheres an air or a nitrogen. Changes in temperature and pressure inside the grinding vessels were measured during mechanical processing in an air atmosphere. The ZnO(Cl)/V_30/300 sample reached the highest pressure (1161 mbar) and temperature (30.3 °C) in the milling vessels and for the ZnO(ac)/V_CH_30/300 sample the highest temperature difference was measured at the beginning and at the end of the milling (7 °C). The phase transformation, chemical composition and particle size of the hybrid nanocomposite materials were investigated using X-ray diffraction method, Fourier-transform infrared spectroscopy, X-ray fluorescence spectroscopy, carbon phase analysis and particle size distribution analysis. Changes in morphology and particle arrangement were characterised using scanning electron microscopy. The effect of mechanical processing in a protective atmosphere on surface properties such as specific surface area, surface conductivity and ζ-potential were demonstrated in relation to the type of precursor used for the preparation of ZnO nanoparticles in the structure of hybrid nanocomposite materials.