超疏水材料表面的空气膜与自清洁作用对细菌黏附行为的影响

Abstract

【中文摘要】超疏水材料因其特殊的润湿性被广泛用作抑菌材料，许多研究认为超疏水材料与细菌溶液间的空气膜是其抑菌 的关键因素，但鲜有研究能直接证明空气对细菌黏附的影响。本文应用电化学阳极氧化法和分子自组装方法，在钛箔表 面制备了超亲水的二氧化钛纳米孔柱阵列(NPA)和超疏水的NPA。通过超声去除超疏水NPA固-液界面的空气膜，对 比研究细菌在超疏水样品有无超声情况下的黏附，其中细菌黏附应用荧光显微镜进行表征。结果表明，超疏水NPA相 对于超亲水NPA表现出明显的抗菌效果；肉眼可见的空气膜在局部区域内，可明显阻碍细菌的黏附，从而影响细菌在 超疏水材料表面的分布；但从黏附细菌的整体数量对比，超疏水NPA固-液界面的空气膜对细菌的黏附数量并没有显著 影响。此外，超疏水材料表面黏附的细菌易在常规的实验漂洗过程中脱离材料，这提示了在考察超疏水材料的抑菌性能 时，需要考虑材料的自清洁作用对其抑菌性能表征的干扰。 【Abstract】Super-hydrophobic materials have been widely used as antibacterial materials due to their special wettability.Numerous studies state that the air trapped between super-hydrophobic materials and the bacterial solution constitute the critical factor for antibacterial properties. However,only a few studies can directly prove that trapped air can affect bacterial adhesion.In this paper,super-hydrophilic titanium dioxide (T1O2 ) nano porous coatings (NPA) and super-hydrophobic T1O2 NPA are constructed on titanium foil by combining electrochemicd anodization and molecular self-assembly. We utilize ultra-sonication to remove trapped air at the solid-liquid interface of the super-hydro phobic NPA and compare bacterial adhesion on super-hydrophobic NPA with and without ultra-sonication treatments. Furthermore，the bacteria adhesion is characterized by a fluorescence microscope. Results show that the super-hydro phobic NPA exerts a more noticeable antibacterial effect than the super-hydrophilic material does. In some regions of the sample surface, the visible air film can hinder bacteria adhesion and affect the distribution of adherent bacteria. However, the trapped air film at the sol id-liquid interface of super-hydrophobic NPA does not significantly affect the overall number of adherent bacteria In addition, the adherent bacteria on the super-hydrophobic surface are easily detached from the materials during the routine experimentd rinsing process. It is suggested that the interference of the self-cleaning effect of materials on the characterizat ion of antibacterid properties should be considered when these antibacterid properties of super-hydrophobic materials are investigated.