Preparation and antibacterial properties of β-SiAlON/AlN composite ceramics

Abstract

In this study, β-SiAlON/aluminum nitride (AlN) composite ceramics were synthesized using a wet-mixing method at 1500 °C under a N2 atmosphere. X-ray diffraction and scanning electron microscopy were used to characterize the ceramics before and after immersing them in water for 7 d. The change in pH and release of ammonia nitrogen were studied to investigate the reaction and antibacterial mechanisms of AlN hydrolysis. The effects of the AlN content on the phase composition, microstructure, chemical properties, and antibacterial efficacy of the composite ceramics were investigated. As the AlN content increased, the antibacterial efficiency gradually increased. The antibacterial efficiency of the composite ceramic with an AlN content of 60 wt% was 100%, indicating that an increase in pH and amount of ammonia nitrogen could synergistically enhance the antibacterial effect. However, in a lysogeny broth medium, the buffering effect of the culture medium and promotion of bacterial proliferation may reduce the antibacterial efficiency. Therefore, β-SiAlON/AlN composite ceramics show considerable potential for antibacterial applications.