Characterization And Physical Properties Of Bionic Periosteum Of PVDF Doped With Zinc And Magnesium

Objective:To prepare Zinc-magnesium doped polyvinylidene fluoride（PVDF）bionic periosteum,analyze its characterization and physical properties,and carry out hydrophilic modification,so as to make preliminary exploration for subsequent research.Method:Polyvinylidene fluoride nanofiber films with concentrations of 1%,2%,3%zinc chloride and/or magnesium chloride were prepared by electrospinning technology,and the release amounts of zinc and/or magnesium ions in different time periods were measured.Scanning electron microscopy,Fourier infrared spectrometer,contact Angle measuring instrument and universal testing machine were used to characterize the nanofiber films and analyze the mechanical properties.With the application of surface modification technology,water-loving Ti O₂ was attached to the surface of nanofiber membrane by"bioadhesive"produced by polydopamine,and the film before and after mixing zinc and magnesium was hydrophilic modified.Results:（1）Scanning electron microscopy showed that the diameter of 1%MgCl₂-PVDF membrane nanofibers was significantly smaller than that of PVDF membrane（P<0.001）,1%ZnCl₂-PVDF membrane（P<0.001）and 1%（ZnCl₂+MgCl₂）-PVDF membrane（P<0.001）.There was statistical significance in fiber diameter between different metal salt supplemental levels（P<0.05）,and 3%supplemental levels were significantly greater than 1%（P<0.001）and 2%（P<0.001）supplemental levels.（2）Extraction experiment:Magnesium ion release showed a gradual decreasing trend,and the magnesium ion release of 1%（ZnCl₂+MgCl₂）-PVDF membrane was more stable than that of other groups during the 14-day extraction experiment.The release of zinc ions in1%Zn Cl2-PVDF membrane was more stable than that in other groups.（3）Fourier infrared spectrum:The contents ofβphase in 1%ZnCl₂-PVDF membrane,1%MgCl₂-PVDF membrane,1%（ZnCl₂+MgCl₂）-PVDF membrane and blank PVDF membrane were calculated by infrared spectrum analysis.The content ofβphase in each membrane was43.6%,43.6%,44.5%and 43.9%,respectively.（4）Mechanical properties:The tensile load of 1%ZnCl₂-PVDF membrane,1%MgCl₂-PVDF membrane,1%（ZnCl₂+MgCl₂）-PVDF membrane and blank PVDF membrane was tested by universal testing machine,and the mechanical properties of the four groups of membranes were analyzed.It was found that the tensile load of the membranes was significantly enhanced after adding metal salt.The best method was 1%ZnCl₂-PVDF membrane.（5）Hydrophilic modification:There was no significant difference in the contact Angle between the first 1%ZnCl₂-PVDF membrane,1%MgCl₂-PVDF membrane,1%（ZnCl₂+MgCl₂）-PVDF membrane and blank PVDF membrane,which were 135.3°,132.9°,131.6°,137.7°,respectively.After modification,the mean contact angles of each group were 80.0°,78.0°,76.3°and 79.0°,respectively.The results showed that the hydrophilic modification effect was obvious.Conclusion:PVDF nanofiber films containing 1%ZnCl₂ and/or MgCl₂have good surface morphology and mechanical properties,which may provide evidence for further exploration and application.