Preparation And Properties Of Magnesium Oxide And Its Composite Antibacterial Materials

Antimicrobial materials have been paid more and more attention in the field of biological medicine,water treatment and environmental protection.MgO has become a research hotspot of antibacterial materials,as it has good thermal stability,low toxicity and broad spectrum antimicrobial properties.However,the relationship between the morphology,size and antibacterial properties and how to improve the antibacterial properties of MgO has yet to be studied.In this paper,a series of different morphologies and sizes of MgO were synthesized successfully by optimizing preparation process parameters,and the correspondence between structure and antibacterial properties of MgO was revealed.Magnesium oxide-graphene composites were designed and synthesized,and its properties were evaluated and antibacterial mechanism was clarified.The main contents of the paper are as follows:?1?Preparation of MgO with different morphology and size.The five kinds of MgO in the form of Rodlike,Sheet,Flowerlike,Sphere,Cubic morphology were prepared by using MgCl₂·6H₂O and MgSO₄ as raw materials with the help of different precipitating agents,such as NH₄HCO₃,Na₂CO₃ and NH₃·H₂O.Besides,the Rodlike MgO with different sizes was synthesized by adjusting reaction parameters.The structural characterization of the above materials was carried out by using XRD,SEM and TEM.?2?Study on the antibacterial properties and mechanism of MgO.Using E.coli and S.aureus as the model bacteria,it shows that Rodlike,Sheet,Flowerlike,Sphere except Cubic MgO have good antibacterial activity throught colony counting method analysising.With the decrease of the size,the antibacterial properties of the Rodlike MgO increase.?3?Preparation and antibacterial properties of MgO-rGO composite materials.MgO nanosheets and MgO-rGO composite materials were prepared by using microwave hydrothermal method and regulating the addition of graphene oxide in the reaction,respectively.It was found that the particle size of composite materials reduced after adding rGO and the crystallinity of the materials decreased gradually with the increase of content of rGO by performing XRD,FESEM,TEM and other tests.The performance of MgO-rGO composites was significantly improved compared with MgO nanosheets.The inactivation and morphology of bacteria were detected by fluorescence double staining and bacterial fixation method.The results show that MgO-rGO composites can contact with bacteria more easily,which more directly leads to the mechanical damage of bacteria,thus the antibacterial property is improved significantly.?5?Preparation and properties of magnesia-based antibacterial coatings.Antibacterial coatings were prepared by adding magnesium oxide nanosheets and magnesium-graphene composites to modifiy polyvinyl acetate paint.The antimicrobial properties were tested by the growth curve,and the results showed that the antibacterial coatings prepared with the content of 12%magnesium oxide-graphene composites had good antibacterial properties.