Preparation And Properties Of Titanium Dioxide Composites With Antibacterial Function

Bacteria are ubiquitous,in every corner of our daily life,it can be transmitted through contact,respiratory tract,digestive tract,blood and other ways.Bacterial invasion of human body will lead to a variety of diseases,so the preparation of antibacterial materials is particularly important.Staphylococcus aureus(S.aureus)is a common pathogen that causes food poisoning,which belongs to the third largest microbial pathogen.It has a certain tolerance to high temperature and can survive in harsh environment.In this paper,nano titanium dioxide and methyl methacrylate and their derivatives as raw materials,combined with the characteristics of nanoparticles and polymers through copolymerization prepared a photocatalytic antibacterial material,S.aureus as an example to study the application potential of this material as an antibacterial material,this topic mainly includes the following three aspects of content.Firstly,the effects of ethylene glycol methyl dimethacrylate,triethyl phosphate and stearic acid on the properties of polymethyl methacrylate were studied by orthogonal test.L9(33)orthogonal experiment results determined that the additive ratio of T-PMMA was 4%ethylene glycol methyl dimethacrylate,5%triethyl phosphate,8%stearic acid.Transparent PSMA nanocomposites were prepared by copolymerization with styrene mixed solution dispersed with TiO2 nanoparticles.Through the characterization of structure and morphology,it was found that the nano titanium dioxide was evenly dispersed in the composite material,and the color of the material was gradually deepened with the increase of TiO2 content.When the content of nano-titanium dioxide increased from 0.5%to 2.0%,the UV shielding wavelength of the composites increased from 366 nm to 371 nm,and the transmittance remained above 86%.The prepared composites can be used as optical filters.The diameter of antibacterial zone of the composite material with TiO2 content of 2.0%against S.aureus was 26.0 mm,and this material has the potential to be used as antibacterial packaging material.Secondly,in order to further improve the mechanical properties of the material,the transparent PSEM nanocomposite was prepared by copolymerization of styrene,polyethylene glycol(600)dimethacrylate and ethoxylated trimethylolpropane trimethacrylate dispersed with titanium dioxide nanoparticles.By SEM,EDS,TEM,XPS and other tests,it was proved that the nanoparticles were uniformly dispersed in the polymer matrix.The transmittance test showed that PSEM nanocomposite can shield ultraviolet light with wavelength of 200-368 nm,reduce the transmittance of blue and violet light in the range of 368-500 nm,and the transmittance of visible light in the range of 600-800 nm is about 91%.Due to the introduction of PEG chain into the polymer chain,the mechanical properties of the composite have been improved,with the maximum notched impact strength,tensile strength,bending stress and hardness reaching 56.11 KJ/m2,54 MPa,88.02 MPa and 74 HRR,respectively.In addition,when the content of titanium dioxide was 3.3%,the antibacterial zone diameter of the composite against S.aureus was 28.0 mm.The molecular structure design ensures that PSEM nanocomposites have good mechanical properties and stable antibacterial properties.Finally,carbon fibers loaded with silver nanoparticles were prepared by modification and reduction methods,and dispersed in 5-PSEM matrix to prepare Ag@C-PM composites.It was found that the carbon fibers were uniformly dispersed in the polymer matrix by SEM.Through UV-Vis and TGA tests,it is proved that the composites have good thermal stability and UV resistance.The thermal decomposition temperature(T5%loss)of all the composites is higher than 239.9℃.When the fiber content increases from 0%to 8%,the thermal decomposition temperature increases from 239.9℃ to 248.5℃.Tensile and antibacterial tests showed that the tensile strength of 8%-Ag@C-PM composite reached 56.8 MPa and showed a clear clean zone with a diameter of 34.2 mm bacteriostatic zone.Finally,the composite containing silver nanoparticles and titanium dioxide nanoparticles achieved the ideal antibacterial effect.