Production and characterization of antibacterial glass and glass ceramic materials

Abstract

Glass and glass ceramic materials are very important materials in human life, such as kitchen utensils, windows and automobile glass, and their importance has been increasing day by day. the consumption of glass and glass ceramics has been also increasing with the increase in the population of the world. The efforts to add antibacterial properties to many industrial products to protect them from disease-causing microorganisms such as bacteria mold, virus, etc. have increased greatly and scientists have been developing new methods to overcome this threat. There are many ways to struggle with bacteria and viruses. The addition of ions with antibacterial properties in order to prevent the growth of bacteria is one of these solutions. Some metal ions, such as silver, zinc, strontium, and copper, have a function for fighting bacteria and inactivating the proteins of these bacteria's enzymes. For this reason, it is important to add such ions to the glass and glass ceramic in order to gain them antibacterial properties. Today, antibacterial properties of glass materials are gained by using coating with sol-gel or ion exchange methods. Within the scope of this doctoral thesis, it was aimed to develop antibacterial glass and glass ceramic materials by using classical melting method, without the need for sol-gel and ion exchange methods. This method is an easy and economic way. Antibacterial glasses produced by this method can be an alternative with superior qualities and lower costs than those of produced by sol-gel and ion exchange methods in todays' technology. The requirement for high purity raw materials in the sol-gel method makes mass production costly. The chemicals to be used while creating the sol-gel are expensive and have no alternative raw materials. Compared to conventional melting, long cycle times and additional unit investments are required in the sol-gel method. During annealing, coating is made by spraying method and homogeneous coating cannot be achieved on the inner surface of the glass due to the inability to spray properly. Over time, due to the peeling of the coating, its antibacterial property is lost, and it becomes harmful for human health as the decomposed chemicals pass into the product. However, antibacterial glasses obtained by melting metal ions such as silver, zinc, copper and strontium, which provide antibacterial properties, eliminate the disadvantages of peeling. Within the scope of the study, silver, zinc, copper and strontium were selected as antibacterial agents and added to the soda lime and borosilicate glass batches in different amounts in oxide form. Glasses were obtained by using classical melting method at the suitable temperatures for each glass type. First of all, antibacterial activity tests, which is the main subject of the study, were performed. Afterwards, studies were continued with compositions that are suitable for antibacterial properties and can provide more advantages in terms of raw material costs. Secondly, ion release tests of these antibacterial ions, which can be harmful for human health at high amounts, were carried out. Afterwards, structural analyzes and some tests were carried out on the obtained samples to determine the optical, physical and mechanical properties of these glasses by using different techniques. Finally, detailed melting performances of these glass compositions were examined with a high-temperature monitoring system in order to demonstrate the manufacturability of these glass compositions. In addition, the crystallization temperature of antibacterial borosilicate glass was determined by the "Differential Thermal Analysis" method and its forming potential to glass ceramic structure was investigated. Crystal structures were determined by using XRD and Scanning Electron Microscopy (SEM) analyzes. Furthermore, antibacterial activity, ion release, optical, physical and mechanical properties of the obtained samples were also determined. As a result, antibacterial glass products doped with silver oxide and zinc oxide were provided to the soda lime glass industry. Besides household items, borosilicate glasses are frequently used in pharmaceutical packaging, especially vaccine vials, due to their inertness and chemical resistance. The need for borosilicate glass has also increased for vaccines developed as a solution to the Covid-19 pandemic, which has affected the whole world from the beginning of 2020 and whose effects are still continuing today and adding antibacterial properties to borosilicate glasses used in the health field is an important output of the Ph.D. study. Also, this study will enable the production of antibacterial glass and glass ceramic products without requiring any extra cost and without the need to change the production parameters and furnace design. Thus, it seen foreseen that a significant contribution can be made to Turkey's economy.