Antibacterial characteristics of carbon-coated CaCO_3/MgO powder led by the pyrolysis of poly (vinyl alcohol)-dolomite mixture

摘要

In order to reduce oral diseases with bacterial growth, carbon-coated CaCO_3/MgO powder possessing antibacterial activity was obtained by the pyrolysis of poly (vinyl alcohol)-dolomite mixture at 700 deg C in an argon gas. Evaluation of the antibacterial activity was performed by colony count method, using Escherichia coli and Staphylococcus aureus. CaCO_3 and MgO were formed at the temperature range from 400 to 700 deg C. At 800 deg C, CaO was produced by the calcination of CaCO_3. The powders after PVA pyrolysis turned into black, i.e., the formation of carbon on its surface. In the case without PVA, the formation temperature of CaCO_3/MgO exceeded 100 deg C than the mixture of dolomite and PVA. Antibacterial activity of the carbon-coated CaCO_3/MgO powder against Staphylococcus aureus was found to be stronger than against Escherichia coli. Comparing with CaCO_3/MgO powder without carbon, it was found that the antibacterial action was reduced by forming carbon on its surface.