铝合金超疏水表面制备与耐腐蚀性能研究

发布时间：2018-01-22 21:01

  本文关键词： 铝合金 超疏水表面 BTESPT 稳定性 耐腐蚀　出处：《南昌航空大学》2017年硕士论文　论文类型：学位论文

【摘要】：本论文以铝合金为基体材料,利用盐酸刻蚀及沸水处理在其表面构建微纳米多级粗糙结构,然后通过溶液浸泡法在其表面依次沉积双-[3-(三乙氧基)硅丙基]四硫化物(BTESPT)和硬脂酸(STA),成功制备出超疏水表面(接触角为167.0±2.3°,滚动角为3.5±0.8°)为了方便,将制备的超疏水样品简记为Al-HCl-H_2O-BTE-STA。利用场发射扫描电子显微镜(FE-SEM)、X-射线光电子谱(XPS)、接触角测量仪等对样品的表面形貌、表面组成、表面润湿性进行了表征;通过监测样品表面润湿性的变化,对超疏水样品暴露在大气环境及超声振荡的乙醇溶液中的稳定性进行了研究;通过监测样品表面形貌、表面成分和表面润湿性的变化,对样品在不同环境中(静态盐水浸泡、动态盐水浸泡、中性盐雾)的耐腐蚀性能进行了研究。具体结果如下:(1)表面形貌、成分、润湿性。经盐酸刻蚀后,铝合金表面形成大量微米级阶梯状粗糙结构,再经沸水处理,微米级结构上会生长出一层致密的水合氧化铝(AlOOH)纳米片。经双-[3-(三乙氧基)硅丙基]四硫化物(BTESPT)和硬脂酸(STA)修饰后,样品表面静态接触角升至167.0±2.3°,滚动角为3.5±0.8°。(2)稳定性。制备的超疏水样品在大气环境和超声振荡的乙醇中具有良好的稳定性。暴露在大气环境中(温度为20-30℃,相对湿度为50-60%)100天后,样品表面仍具有极佳的超疏水特性(静态接触角163.7±1.8°,滚动角为10.0±1.1°);在乙醇(40 KHz,100 W)中超声振荡60 min后,接触角变为159.9±2.5°,滚动角变成20.0±1.2°。(3)耐腐蚀性。(i)超疏水样品在静止NaCl溶液(3.5 wt.%,18天)中的腐蚀。FE-SEM分析表明,浸泡前后表面微观形貌基本不变。EDS分析表明,浸泡后表面氧元素相对含量增加,氧元素与铝元素的含量比值[O]/[Al]由0.84提升至0.98。浸泡后,超疏水样品接触角仍高达152.4±2.1°,滚动角增大至49.0±1.2°。(ii)超疏水样品在流动NaCl溶液(3.5 wt.%,50 h)中的腐蚀。将超疏水样品浸入流速分别为0.5 m/s、1.0 m/s、2 m/s的流动NaCl溶液中50小时后,接触角分别下降至165.2±1.5°、162.2±2.4°、155.6±1.7°,滚动角变为15.0±1.2°、18.7±2.3°、36.2±2.5°。FE-SEM分析表明,浸泡前后表面微观形貌基本不变。EDS分析表明,当流速为2 m/s时,浸泡后表面氧元素与铝元素含量的比值[O]/[Al]由0.84提升至0.91。(iii)中性盐雾试验(48小时):暴露在中性盐雾环境中48 h后,超疏水表面微观形貌变化不大,表面氧元素于铝元素的含量比值[O]/[Al]由0.84变成了0.96,接触角和滚动角分别变成159.5±2.0°、24.0±1.1°。特别需要指出的是,在相同的实验条件下,本论文制备的Al-HCl-H_2O-BTE-STA超疏水样品与其对照超疏水样品(如只具有微米级粗糙结构的超疏水表面Al-HCl-BTE-STA,不含BTESPT层的Al-HCl-H_2O-STA等)相比具有突出的稳定性和耐腐蚀性。这主要是由于以下原因:(1)沸水处理在表面引入了氧化层。一方面,氧化层具有阻隔效应,能够延缓腐蚀发生;另一方面,氧化层表面的羟基有利于提高BTESPT薄膜与基体之间的结合,从而增强薄膜稳定性。(2)BTESPT/STA双层薄膜提高了样品的耐腐蚀性。BTESPT具有很好的腐蚀防护效果,并且,热处理后具有一定的疏水性。然而,单独使用BTESPT作为低表面能分子,表面超疏水性欠佳。因此,另外在其表面沉积了STA分子,从而构筑了稳定的超疏水表面。
[Abstract]:In this paper, Aluminum Alloy as matrix material, by etching and boiling water treatment on the surface of building micro nano hierarchical roughness of hydrochloric acid, and then through the solution immersion method on the surface of successively deposited double -[3- (triethoxysilyl) propyl] four silicon sulfide (BTESPT) and stearic acid (STA), the successful preparation of superhydrophobic surface (the contact angle is 167 + 2.3 degrees, the rolling angle is 3.5 + 0.8 degrees) in order to facilitate the preparation of super hydrophobic sample will be denoted as Al-HCl-H_2O-BTE-STA. by field emission scanning electron microscopy (FE-SEM), X- ray photoelectron spectroscopy (XPS), composed of surface topography and contact angle measurement on the sample surface, surface wettability the characterization; through monitoring the change of sample surface wetting of the samples exposed on the super hydrophobic stability in ethanol solution and ultrasonic oscillation in the atmospheric environment were studied; by monitoring the sample surface morphology, surface composition and surface wettability The change of samples in different environments (static dynamic brine, brine, salt spray corrosion resistance) were studied. The main results are as follows: (1) the surface morphology, composition, wettability. After acid etching, the formation of a large number of micron order ladder rough surface Aluminum Alloy, again after boiling water treatment, micron structure will grow out of a dense layer of alumina hydrate (AlOOH) nanosheets. By double -[3- (triethoxysilyl) propyl] four silicon sulfide (BTESPT) and stearic acid (STA) modified sample surface static contact angle to 167 plus or minus 2.3 degrees, the rolling angle is 3.5. 0.8 degrees. (2) stability. The samples have good stability in the atmospheric environment and ultrasonic ethanol preparation of super hydrophobic. Exposure to atmospheric environment (temperature of 20-30, the relative humidity is 50-60%) 100 days later, the sample surface has excellent super hydrophobic characteristic (static contact angle 163.7 + 1.8 掳,婊氬姩瑙掍负10.0卤1.1掳);鍦ㄤ箼閱，

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