镁合金表面Zn改性MgO复合陶瓷层的微弧氧化制备及其抗菌性能

Micro-arc oxidation preparation and antibacterial properties of Zn-modified MgO composite ceramic layer on Mg alloy surface

微弧氧化膜层经功能元素改性后引起的表面非均匀结构限制了其进一步发展。本文通过聚二烯丙基二甲基氯化铵(PDDA)包覆的ZnO纳米颗粒,结合微弧氧化技术制备了表面均匀的Zn改性MgO复合陶瓷层(Zn/MgO-PDDA),系统研究了其微观组织结构、物相成分、亲水性、耐蚀性及抗菌性。结果表明,PDDA促进了Zn-O-P无定形沉积物的均匀生成,并改善了陶瓷层的致密性和孔隙率。尺寸更小、面积更大的沉积物赋予了陶瓷层更理想的亲水性。陶瓷层的耐蚀性得到显著提高:相比于非均匀的复合陶瓷层,Zn/MgO-PDDA的自腐蚀电流密度降低了1个数量级,电化学阻抗为0.01 Hz时|Z|提升了1个数量级。沉积物合理的表面分布促使陶瓷层的抗菌率提升至91.3%。因此,PDDA可有效促进微弧氧化层的均匀化制备并显著提升功能性陶瓷层的各项性能。

The non-uniform surface structure caused by the modification of functional elements in micro-arc oxidation limits the further development of the coating.In this work,Zn/MgO-PDDA with uniform surface was prepared by PDDA-coated ZnO nanoparticles,and its microstructure,phase composition,hydrophilicity,corrosion resistance,and antibacterial properties were systematically studied.Results show that PDDA promoted the uniform generation of Zn-O-P amorphous deposition and improved the compactness and porosity of the ceramic layer.The smaller size and larger area of the depositions led to better hydrophilicity of ceramic layer.The corrosion resistance of the ceramic layer was significantly improved:compared with non-uniform composite ceramic layer,the self-corrosion current density(icor)was reduced by one order of magnitude,and IZlo.o0 Hz of electrochemical impedance spectroscopy(EIS)was increased by one order of magnitude.The reasonable surface distribution of the depositions promoted the antibacterial rate of Zn/MgO-PDDA to 91.3%.Thus,PDDA can effectively promote the uniform preparation of micro-arc oxidation and significantly improve the performance of the functional ceramic layer.