Preparation Of Antibacterial Functional Paper Loaded With Nano Zinc Oxide/graphene Quantum Dots

Due to its good antibacterial and photocatalytic properties,nano zinc oxide(ZnO)has attracted the attention of researchers from all walks of life and has been widely used in many fields.However,the nano material particles are small,and as the powder nano materials are widely used,the nanoparticles will inevitably enter the environment,causing some potential harm to the environment and human health.Therefore,the Zn2+ is introduced into the fibers of the paper substrate by the dipping method,and then the antibacterial paper loaded with different morphology nano-ZnO is synthesized by one-step hydrothermal method.It can be immobilized while ensuring antibacterial properties to avoid secondary pollution.Different reaction conditions produce nano-ZnO particles in the form of rods,needles,and rice grains.The structure and morphology of the product were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).The ZnO nanoparticles supported on the antibacterial paper were all well-crystallized hexagonal wurtzite structure.Through orthogonal experiment,the optimal preparation process is as follows:impregnation temperature is 70℃,immersion time is 2 min,zinc chloride solution concentration is 45%,sodium hydroxide solution pH is 12,antibacterial paper is antibacterial to Escherichia coli The rate can reach 76.9%.In order to further improve the antibacterial property of the antibacterial paper,a graphene quantum dot which can effectively improve the visible light utilization rate of the nano-ZnO and the electron-hole separation efficiency is added in the hydrothermal synthesis stage to prepare a nanometer zinc oxide antibacterial paper doped with quantum dots.Among them,graphene quantum dots are prepared by hydrothermal method from glucose and concentrated sulfuric acid.The quantum dots have a graphene structure by transmission electron microscopy(TEM),Raman spectroscopy,etc.,and the average particle diameter is 6.3± 1.5 nm,which can be at a larger wavelength.Blue fluorescence is excited in the range.It was found that the addition of a small amount of graphene quantum dots slightly inhibited the formation of nano-ZnO,but with the increase of the addition amount of graphene quantum dots,the antibacterial property of antibacterial paper was significantly improved.When the addition amount was 0.05 g/L,the antibacterial effect was observed.The antibacterial rate of paper can reach 83.3%.In order to impart good self-cleaning and anti-pollution properties to the functional paper,the use of the antibacterial paper is further broadened,and stearic acid is deposited on the surface of the functional paper by condensation deposition,so that the functional paper has good hydrophobicity.It was found by SEM analysis that stearic acid was deposited on the surface of the fiber in a micron size.The longer the deposition time,the better the hydrophobicity of the functional paper.However,longer deposition times can affect the antibacterial properties of functional paper.Considering that the deposition time of stearic acid is 10 min,the functional paper can achieve better hydrophobicity and antibacterial effect.The contact angle of functional paper to water droplets is 122.8°,and the inhibition rate against Escherichia coli is 85.71%.