Design And Preparation Of Self-cleaning ZnO Nanocoating And The Research Of Its Bacterial Anti-adhesion Property

Bacterial adhesion is a common problem in the fields of biomedical material,biochemical analysis,biochemical engineering,marine pollution prevention and so on.The process of bacterial adhesion is very complex,which has not been understood clearly now,but reserchers still have acheieved some enlightenments from previous works.According to our knowledge,reasonable design of the coating surface is the only way to reduce and eliminate the bacterial adhesion.ZnO is one of non-toxic inorganic antibacterial agents,it has a wide antimicrobial spectrum with no resistance to bacterial,which has a great application prospect to prepare antimicrobial coating.In this work,we have studied a number of factors that may affect the bacterial adhesion property of the ZnO coating were comprehesively studied,including surface morphology,surface wettability,surface roughness,and including bacteria species.The suitable surface morphology of ZnO coating that dramatically reduce bacterial adhesion was obtained.Based on these,the transparent superhydrophobic ZnO coating with self-cleaning property was prepared.The main work of this paper is as follows:(1)A series of ZnO coatings with different morphologies were prepared by the solvent thermal method,including zero-dimensional nano-particle,one-dimensional nano-rod,and three-dimensional micro-flower,which were characterized by XRD and SEM.The adhesion of Staphylococcus aureus and Escherichia coli cells to different morphology of ZnO coatings were studied.The results showed that the adhesion of Staphylococcus aureus and Escherichia coli were obviously affected by different surface morphology and surface roughness,the bacterial adhesion on the three-dimensional micro-flower surface was the worst,but it was oppsite on the zero-dimensional nano-particle surface.(2)Different wettability of ZnO coatings were obtained by modification with hexadecyltrimethoxysilane,and their bacterial adhesion behaviors were studied.Theresults showed that both Staphylococcus aureus and Escherichia coli adhered faster on the hydrophobic surface than hydrophilic surface,and the amount of adhesive Staphylococcus aureus was larger than that of Escherichia coli.As for ZnO coating with nanoparticles,whether it was hydrophilic or hydrophobic,there was no significant difference in bacterial adhesion.(3)A robust ZnO nanoparticle coating with high transmittance and superhydrophobicity was reported,which was prepared by a facile sol-gel method.To take control of the transparency and hydrophobility of the ZnO coating,the concentration of Zn2+ and CTAB was optimized.The as-prepared ZnO coating showed remarkable stability against water dripping impact,sand impact abrasion and scratching test,while retaining its superhydrophobicity and transparency.Furthermore,the ZnO coating also showed self-cleaning,UV-blocking and anti-bioadhesion properties,which had a great potential application to prepare self-cleaning coatings.