Nanokompozitní plniva na bázi jílových minerálů a hydroxyapatitu pro polymerní kompozity

Abstract

The dissertation thesis deals with preparation of Ca-deficient hydroxyapatite anchored on the vermiculites (from 4 deposits) and montmorillonite (from 1 deposit) particles surface. The composites of clay mineral/Ca-deficient hydroxyapatite are prepared by precipitation and sonication methods on Na- and Mg- forms of clay minerals. Prepared composites are characterized using X-ray diffraction analysis, infrared spectroscopy, scanning electron microscopy and X-ray fluorescence spectroscopy. The composites are also studied for stability, sorption properties and evaluation of specific surface area. The influence of preparation method where the formation of Ca-deficient hydroxyapatite is studied and also the effect of monoionic forms of clay mineral are compared. The results show that the way of preparation or monoionic forms of clays do not influence creation of Ca-deficient hydroxyapatite. Montmorillonite and one type of vermiculite were selected for Ca-deficient hydroxyapatite preparation on organically modified clay. Selected clay minerals are modified with chlorhexidine diacetate drug. On the surface of organically modified clay mineral the Ca-deficient hydroxyapatite is prepared. Resulting hybrid anorgano-organic modified clay mineral is characterized using XRD analysis, infrared spectroscopy and scanning electron microscopy. Results showed creation of Ca-deficient hydroxyapatite on the surface of organically modified vermiculite and montmorillonite. The prepared composites exhibit antimicrobial activity. These hybrid anorgano-organic modified clay minerals are used as fillers for polyethylene composites. Polymer composites are characterised using X-ray diffraction methods and light microscopy. The polyethylene composites are studied for antibacterial activity and the biocompatibility predication. X-ray diffraction methods proved no intercalation of polyethylene into the interlayer space of clay minerals. Antibacterial tests confirm antibacterial activity of all studied polyethylene composites. Prediction of biocompatibility confirmed creation of apatite layer on the surface of polyethylene composites, which is crucial for utilization in biomedical applications.