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The effect of the SrO addition on the microstructure and structure of the glazes from the SiO2–Al2O3–CaO–MgO–K2O system was investigated in this study. The results were obtained by testing the ability of the frits crystallization, the stability of the crystallizing phases during the single-step fast-firing cycle depending on their chemical composition and the effect of addition of strontium oxide. Differential scanning calorimetry (DSC) curves showed that all glazes crystallized, and diopside and anorthite were mainly identified as dominant phases in the obtained glazes, while the size and amount of each depended on the amount of SrO introduced. The thermal characteristic of the frits was carried out using DSC, and crystalline phases were determined by X-ray diffractometry. The glaze microstructure was investigated by scanning electron microscopy and transmission electron microscopy. Additional information on the microstructure of frits was derived from spectroscopic studies in the mid-infrared range.

The majority of parts used in the electrical apparatus are made of polymer materials; however, pure polymers do not provide the antibacterial functionality. Therefore, in order to add such property to them it is necessary to use antibacterial additives. The study concerned intercalation of triclosan (TCS) as biocide into montmorillonite (MMT) interlayer spaces was performed in order to increase TCS resistance to high-temperature treatment, which is necessary during polymer composite processing. The obtained MMT + TCS hybrids were tested for structural and antibacterial properties. The degree of biocide intercalation was assessed using X-ray diffractometry, by analyzing changes in MMT interlayer distance, and thermal analysis was performed to assess the effect of the intercalation process on the thermal stability of TCS. Antibacterial tests against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were also carried out on the obtained MMT + TCS powders in order to confirm the bactericidal properties of TCS released from the clay after the intercalation process. As a final proof of concept, the hybrid powder, namely MMT with incorporated TCS, was incorporated into polycarbonate matrix and antibacterial activity of modified polymer samples was tested. The obtained results have proven that montmorillonite–triclosan hybrid is an effective antibacterial additive with enhanced thermal stability which can be applied for protection of plastic parts used in electrical devices.

This paper presents the characteristics of magnesium aluminium silicate–gentamicin complexes for drug delivery systems. The work describes the results of studies on the successful introduction of gentamicin (an aminoglycoside antibiotic) into the interlayers of smectite clay and examines the possible use of intercalated smectite as a carrier for sustained drug release. Characterisation of magnesium aluminium silicate–gentamicin complexes was carried out by means of X-ray diffraction, Fourier transform infrared spectroscopy, thermal analysis and scanning electron microscopy with EDX analysis. The possibility of using the gentamicin intercalated smectite as a carrier for sustained release of the drug was investigated during in vitro study, in which the release rate of gentamicin from the smectite clay matrix was monitored based on absorption at 330 nm using a UV–Vis spectrometer and the kinetic of drug release was evaluated based on the zero-order, first-order, Higuchi and Korsmeyer–Peppas models. The results confirmed the efficiency of intercalation and indicate the potential for introducing gentamicin into the interlayer space of montmorillonite. Accordingly, the obtained material may thus be used as a drug carrier in modulated drug delivery systems.

The aim of this study was to investigate the influence of the addition of smectite clay fillers to a polylactide matrix on the physical properties of the nanocomposites thus created, studied during the degradation process. A small amount of nanofiller (3–10 mass %) was used, and the clay was additionally modified with organic ammonium salt for better compatibility with the polymer matrix. Crystallisation, glass transition and melting temperature of the nanocomposites were investigated, and the resulting thermal, structural and mechanical properties were compared to those of a neat polylactide. The degradation process of the materials was examined during immersion in distilled water at 80 °C for 60 days using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Macroscopic changes were monitored and mechanical properties tested prior to degradation to evaluate the ability of the modified clay filler to reinforce the polymer and enhance elastic modulus, mechanical strength and Brinell hardness. The influence of the modified smectite filler on the thermal, mechanical and structural properties of the nanocomposites during degradation and its dependence on filler content were discussed and confirmed in the study. It was found that the addition of 3 mass% of the clay filler provides an increase of nearly 20 % in tensile strength, with improved stiffness. It was also found that the addition of organically modified clay to the polymer matrix significantly changes the hydrolytic degradation mechanisms of the polylactide, the crystallinity of the polymer and its degradation rate, depending on the amount of the filler.

This paper focusses on the intercalation of clay mineral with gentamicin (an aminoglycoside antibiotic). The smectite clay–gentamicin hybrids were prepared by a solution intercalation at 60∘C and the process was carried out on unmodified smectite clay and on smectite after Na+ ionic activation. The resulting structural/microstructural properties and the potential for introducing gentamicin between smectite clay layers were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopic techniques and transmission electron microscopy and scanning electron microscopy with energy-dispersive spectroscopy X-ray analysis. The results confirm the successful intercalation of gentamicin into the interlayer space of smectite clay, demonstrating that the material thus obtained could potentially be used as a drug carrier.

The surface charge at the calcium phosphate/electrolyte interface is created as a result of the various reactions of surface groups and unequal adsorption of ions of an opposite charge from the solution. Photoacoustic spectroscopy (FT-IR/PAS) has been used for identification of different groups of hydroxy- apatite samples. A complementary study of electrical double layer properties was carried out using potentiometric titration and electrophoretic measurements.

In recent years researchers all over the world have been interested in obtaining the evaluation and medical applications of the composites based on calcium phosphates, mainly hydroxyapatite and TCP. Hydroxyapatite (HAp)-Ca10(PO4)6(OH)2 is a material of high biocompatibility and additionally it is also one of the few bioactive materials able to create direct, and thus permanent, bonding with the bone tissue [1–3]. Full use of the unique properties of the dense hydroxyapatite ceramics is potentially possible only if their mechanical strength and fracture toughness are improved. These effects can be achieved in composite materials with HAp matrix. Among various reinforcing phases applied in the form of particles, platelets, fibers and nanoparticles, zirconia (ZrO2) seems to be the most interesting one, due to its excellent mechanical properties [4]. Toughening mechanism utilizing the tetragonal—monoclinic transformation of ZrO2 as well as the microcracking toughening mechanism resulting from the difference in thermal expansion coefficients of hydroxyapatite and zirconia are expected to occur in HAp-ZrO2 composites [5]. The biological inertness and good biocompatibility of ZrO2 sinters were confirmed by their medical applications [6]. However, in the case of composites containing substrates of excellent biocompatibility, it cannot be assumed that the final material will exhibit the same high level of biocompatibility. Numerous phenomena which occur during the materials processing may affect the phase composition, microstructure, and other properties responsible for the biological reactions. Therefore it is important to perform tests which evaluate the behavior of a composite material in conditions simulating an environment in a living organism. The objective of our study was manufacturing and comparative in vitro evaluation of the HAp-ZrO2 composite and monophase HAp sinters obtained by hot pressing method. The study was performed on dense composite sinters (HAp80 wt%-ZrO220 wt%) and pure HAp used as a reference material. Non-stabilized zirconia powder was produced by precipitation of hydrated ZrO2 from ZrOCl2·8H2O aqueous solution [7]. The HApZrO2 composite powder was synthesized by precipitation of hydroxyapatite in the presence of ZrO2 (wet process). The weighed amount of ZrO2 powder was added to the intensively stirred aqueous suspension of Ca(OH)2. Then the solution of H3PO4 was added slowly to the reaction medium. The precipitate produced was rinsed with distilled water, dried, calcined at 800 ◦C for three hours, and then ground. The composite powder obtained was an initial material for the production of dense HAp-ZrO2 sinters. Hydroxyapatite for dense monophase HAp material was synthesized by the wet method using CaO and H3PO4 as reagents [8]. The precipitate was treated as described above. The samples of monophase HAp ceramics and HApZrO2 composite were hot pressed in the temperature range of 1150 ÷ 1300 ◦C (Thermal Technology Inc. kiln). The pressing was performed in graphite molds under argon atmosphere at a pressure of 25 MPa with a 0.5 hr soaking time, at the highest temperature. The cytotoxicity analyses performed in this study constitute one of the stages of biological analyzes used for evaluation of broadly understood material biocompatibility. Although in vitro systems may not reflect normal in vivo conditions accurately, a cell-culture system is useful to observe phenomena at the cellular level. Such systems have been used to evaluate biocompatibility of implant materials and to study the interactions occurring at the cell-material interface [9]. The whole range of biocompatibility analyzes depends on the duration and kind of contact between an implant material and an organism, and is determined according to the PN-EN ISO 10993-1:1997 standard. The cytotoxicity analyzes are fast, standardised tests which can determine if a given material designed for medical applications contains significant amounts of biologically harmful substances. High sensitivity of these tests result from the isolation of cell cultures and thus lack of defence mechanisms, which accompany the cells within the body. The cytotoxicity tests were performed on the samples according to the standard PN-EN ISO 10993-5 “Biological evaluation of medical products. Cytotoxicity investigations: in vitro methods”. A method of direct contact with a layer of mouse fibroblasts 3T3/Balb evenly