Preparation Of Magnetic Diatomite-based Composites And Study On Their Antibacterial And Absorbent Properties

Electromagnetic interference and bacterial pollution have become one of the urgent problems to be solved in today’s society.The preparation of multifunctional materials with high antibacterial and electromagnetic wave absorption properties is a challenge,but it is also urgently needed.In this study,diatomite has the characteristics of high porosity,low density and high specific surface area as the carrier of ferrite to improve its performance.On this basis,other loss mechanisms are introduced to further improve the performance of the absorbing material.The main research content of this paper is as follows:（1）The Co_xZn_1-xFe₂O₄/diatomite composites were successfully synthesized by sol-gel autocombustion method.The structure and morphology of the Co_xZn_1-xFe₂O₄/diatomite was characterized by XRD,FTIR and SEM.The specific surface area of 0.5CZD measured by BET was 72.20 m²/g.The appropriate doping of magnetic Co²⁺changes the electromagnetic parameters and band structure of the composites,thus improving its antibacterial and microwave absorption properties.When the matching thickness is 4.500 mm,the minimum reflection loss of Co_0.5Zn_0.5Fe₂O₄/diatomite is 1.50 d B lower than that of Zn Fe₂O₄/diatomite.In addition,the antibacterial results showed that the Co_0.5Zn_0.5Fe₂O₄/diatomite sample had the best antibacterial effect on E.coli,and the disinfection rate reached 99%in 30 min.（2）Mn Fe₂O₄/Zn O/diatomite composites were prepared by a hydrothermal water bath method.As an excellent carrier,lightweight porous diatomite can effectively improve the aggregation of ferrite and further enhance the matching impedance and interface polarization effect of the composite.At the same time,by adjusting the amount of Zn O in the composite,synergistic magnetic loss and dielectric loss of the composite can be realized,and excellent electromagnetic wave absorption properties can be obtained.When the content of Zn O was30%,the composite showed excellent electromagnetic wave absorption properties.When the matching thickness is only 3.000 mm,the minimum reflection loss reached-40.40 d B at 9.73GHz.In addition,due to the heterostructure of Zn O-Mn Fe₂O₄,Mn Fe₂O₄/Zn O/diatomite composites have considerable antibacterial properties,with a bactericidal rate of 99%.（3）Mn Fe₂O₄/r GO/Diatomite cladding structure composites were prepared using a direct,one-step hydrothermal technique.The ternary composite has many microwave absorption mechanisms,including interfacial dipole polarization,conductive loss,natural resonance,flux loss,huge kudos to the three-dimensional cladding cross-linked structure and close-packed Mn Fe₂O₄ particles.As a result,compared with unitary or binary composites this ternary composite offers superior capabilities in low and medium frequency microwave absorption.The composite’s minimum reflection loss is-76.56 d B at 7.90 GHz,its thickness is 2.485 mm,and its effective absorption bandwidth is up to 3.61 GHz.Figure 44 table 6 reference 167...