Preparation of a novel antibacterial coating precursor and its antibacterial mechanism

In this study, a novel antibacterial coating precursor was generated from multi-walled carbon nanotubes (MWCNTs) dispersed in an ethanol solution containing polysilazane. The antibacterial properties of this coating precursor were further improved by depositing silver nanoparticles on the surface of MWCNTs. The silver nanoparticles on Ag-MWCNTs were 3-10 nm in diameter and were attached tightly the surface of MWCNTs. A micro nanostructure was achieved on the surface of DH36 marine steel using this precursor. The prepared coating containing Ag-MWCNTs reveals an interwoven three-dimensional through-hole structure. Hydrophobic experiment results showed that the water contact angle of the as-prepared coating was over 150° and sliding angle was below 1°. The antibacterial property of superhydrophobic surface were characterized through an immersion test in the saturated E. coli bacteria solution. Flat colony counting method measurement indicated that the antibacterial rate of superhydrophobic surfaces modified by MWCNTs reached 85% compared to the untreated control group, and the antibacterial rate of superhydrophobic surfaces modified with Ag-MWCNTs increased to 92.9%.