铝基表面超疏水材料的制备工艺、效果及耐蚀性

超疏水表面在自清洁材料、腐蚀防护及微流体运输等领域有着广阔的应用前景,目前对金属超疏水表面的研究较少,且制备方法较复杂,不能大面积制备。分别采用喷砂、阳极氧化、喷砂-阳极氧化等方法在铝基体表面构造粗糙结构并对其进行修饰,制备了超疏水表面,通过SEM、接触角及滚动角测定、腐蚀速率测定等分析了超疏水表面的微观形貌、疏水性能和耐海水腐蚀性能。结果表明:喷砂-阳极氧化法制备的铝金属表面具有微米-纳米二级结构,经氟化处理后,与水的接触角达158°,滚动角为1.5°,疏水性能良好;超疏水表面材料的腐蚀速率比铝材低1个数量级。     

喷砂-阳极氧化法构建分形超疏水Ti6Al4V表面及性能研究

主要采用喷砂-阳极氧化法在Ti6Al4V钛合金表面构建微纳二级复合结构,使用低表面能物质FAS-17(十七氟硅烷)修饰后可获得超疏水表面。结果显示,喷砂形成的微米级凸台与阳极氧化形成的纳米管复合结构表面的液滴接触角达到了159.8°。在空气中放置30d后,仍然具有优异的超疏水性能,并具有一定的耐盐水性能。     

纯钛基体长效超疏水表面的低成本制备

为降低钛基上超疏水表面的制备成本,提高超疏水表面的耐久性能,以喷砂-阳极氧化法在纯钛基体上构造微纳复合粗糙结构,并使用商用氟碳罩光漆直接对其进行修饰获得超疏水性表面。利用傅里叶变换红外光谱(FTIR),场发射扫描电子显微镜(FE-SEM)和接触角测试等技术对超疏水性表面的化学组成、表面形貌、润湿性和表面耐久性进行了研究。结果表明:喷砂处理在钛基表面构筑微米级凹坑,阳极氧化通过形成网状氧化膜在钛基表面构造纳米级结构,氟碳罩光漆修饰该微纳复合粗糙表面后,为表面引入大量含氟基团,使其获得超疏水性能。超疏水性表面与纯水的静态接触角达162°±2.3°,滚动角为2.1°±0.2°,具有优异的环境耐久性。     

铝基超疏水表面的耐海水腐蚀性能研究

研究了喷砂和阳极氧化技术相结合,在铝合金表面构建合适的微米/纳米二级结构,并通过氟硅烷的修饰降低表面自由能,以制备铝基超疏水表面材料,并对表面的耐海水腐蚀性能进行了研究,研究表明,当采用100g/L硫酸、10g/L草酸、10g/L丙三醇作为电解液进行阳极氧化,孔洞孔径达200nm时,接触角达157°。模拟人工海水中的腐蚀实验,结果表明,超疏水表面材料的腐蚀速率比未经处理的空白试样缓慢一个数量级。     

基于多孔氧化铝腐蚀的表面结构制备及其疏水性能研究

先采用阳极氧化法在铝基板上制备了多孔氧化铝(AAO)膜,并以铝基AAO膜作为前驱物,采用化学腐蚀溶液分别制备出了具有纳米结构、微米结构和微纳复合结构表面的薄膜材料结构。利用扫描电子显微镜、荧光分光光度计和电子能量色散谱仪等测试手段分析了薄膜材料表面结构,并在薄膜表面涂覆低表面能物质氟硅烷薄膜研究这些表面结构的疏水性能。研究结果表明:通过控制化学腐蚀时间可以在铝基AAO膜表面分别获取纳米结构、微纳复合结构和微米结构;与未腐蚀的AAO膜表面相比,三种表面结构都有效提高了疏水薄膜表面的疏水性能;在NaOH溶液腐蚀16 min条件下,表面呈现微纳复合结构,具有超疏水性能,水的接触角达到155°。     

“滴水不沾”的一品红

一品红叶面具有优异的超疏水性能,研究发现其表面分布有大量微米级的“人耳”状凹槽和纳米级的“星型”微凸起,这种微纳米级的复合阶层结构能使其表面吸附一层空气膜,液滴与其表面的接触是液、固、气的复合接触.此外,植物的表面有低表面能的蜡状物,微纳米级的复合阶层结构及其表面的低表面能物质的协同作用使其表面显示出优异的超疏水性能,该研究有望为仿生超疏水材料的制备提供有益的启发.     

铝基超疏水表面的制备及其在包装方面的应用进展

在铝基体上构建具有特殊浸润性的超疏水表面,可以赋予其耐腐蚀、防覆冰、润滑减阻等功能,使其具有更大的应用价值和市场前景。制备铝基超疏水表面的方法主要有刻蚀法、阳极氧化法、沉积法、水热法等。化学刻蚀法、阳极氧化法和水热法等操作简单,应用范围广,但在制备过程中用到的强酸强碱等对环境和人体有害;激光刻蚀法等可以控制超疏水表面微观结构的形貌,但使用设备昂贵,难以大范围使用。为拓展超疏水表面的应用领域,开发简便方法制备多级微纳米粗糙结构、使用黏合层加固微观结构、构建自修复超疏水表面是未来的主要研究方向。     

钛表面二氧化钛纳米管/微米坑复合结构的制备及亲水性

为改善钛的生物相容性,促进成骨细胞在其表面的附着与分化,设计了一种新型工艺。通过微弧氧化后酸洗的技术在钛表面制备微米级凹坑(10～20μm)。通过阳极氧化技术在上述微米级凹坑上制备定向生长的二氧化钛纳米管(70～80 nm)。采用微弧氧化、酸洗和阳极氧化复合工艺,制备出二氧化钛纳米管/微米坑复合结构。研究了使用不同电解液制备的微弧氧化涂层所获得复合结构的形貌,分析了复合结构形貌对亲水性的影响。结果表明,采用Na_2B_4O_7电解液制备的微弧氧化涂层所获得的复合结构具有显著的微纳米分级结构特征,并展现出优异的亲水性。     

SiC/Al复合材料超疏水表面的制备

采用化学刻蚀法在SiC/Al复合材料表面构筑微纳结构,通过SEM和表面接触角测量仪分析刻蚀表面的微观形貌特征及润湿特性,并探讨了其与刻蚀时间之间的关系;借助热震试验评价SiC/Al复合材料超疏水表面的温度骤变耐受特性。结果表明:弥散分布的微米级SiC颗粒的存在使得刻蚀后的SiC/Al复合材料表面易形成由微米级粒状结构和纳米级凹坑结构复合而成的微观结构;氟硅烷修饰后的蚀刻表面的接触角最高达到166.8°,滚动角最低为3°,具有很好的超疏水特性;SiC/Al基超疏水表面具有较好的耐受温度骤变特性。     

钢辊热压微模塑-可控剥离法构建聚乙烯超疏水表面

人工超疏水表面能否简单、环保、经济地量产对其实际应用有重要影响。本研究以滚压成型的表面含微坑的钢辊为模板,采用简单的热压微模塑-可控剥离工艺制备了聚乙烯超疏水表面,接触角大于150°,滚动角约为5°。扫描电镜观察表明,钢辊表面具有均匀网格状微米级浅坑,以此为模板微模塑制备的聚乙烯超疏水表面布满明显拉长的微米级山形结构和亚微米级毛刺结构。本文首次报道了直接应用钢辊制备聚合物超疏水表面,可望结合塑料薄膜流延生产工艺,实现聚合物超疏水薄膜或表面规模化生产。     

Facile fabrication of stable superhydrophobic films on aluminum substrates

Compact and uniform layered double hydroxides thin films were fabricated on aluminum substrates using a simple solution-immersion process; upon chemical modification with perfluorosilane, the wettability of the aluminum surface changed from hydrophilic to superhydrophobic. The products were characterized by scanning electron microscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy. It is confirmed that the synergic effect of the surface morphology and the surface free energy contribute to this unique surface water repellence. In addition, the superhydrophobic films possess long-term storage stability and good adhesion strength to aluminum substrates, which enhance their potential practical applications.     

Combined AFM nano-machining and reactive ion etching to fabricate high aspect ratio structures

In this paper, a new combined method of sub-micron high aspect ratio structure fabrication is developed which can be used for production of nano imprint template. The process includes atomic force microscope (AFM) scratch nano-machining and reactive ion etching (RIE) fabrication. First, 40 nm aluminum film was deposited on the silicon substrate by magnetron sputtering, and then sub-micron grooves were fabricated on the aluminum film by nano scratch using AFM diamond tip. As aluminum film is a good mask for etching silicon, high aspect ratio structures were finally fabricated by RIE process. The fabricated structures were studied by SEM, which shows that the grooves are about 400 nm in width and 5 microm in depth. To obtain sub-micron scale groove structures on the aluminum film, experiments of nanomachining on aluminum films under various machining conditions were conducted. The depths of the grooves fabricated using different scratch loads were also studied by the AFM. The result shows that the material properties of the film/substrate are elastic-plastic following nearly a bilinear law with isotropic strain hardening. Combined AFM nanomachining and RIE process provides a relative lower cost nano fabrication technique than traditional e-beam lithography, and it has a good prospect in nano imprint template fabrication.     

化学浴沉积法制备防污自洁聚偏氟乙烯膜

基于"荷叶效应"原理,利用聚偏氟乙烯(PVDF)涂膜构筑微米结构,氧等离子体诱导化学沉积法构筑纳米结构。采用接触角测量仪、原子力显微镜及X光电子能谱仪等研究了PVDF膜表面的微结构及化学组成与疏水性能的关系。结果显示,PVDF溶液涂膜后可形成直径8μm的微球,甲基三氯硅烷修饰的PVDF膜与水的接触角为157°;二甲基二氯硅烷/甲基三氯硅烷混合液修饰的PVDF膜的表面接触角为155°,滚动角2°;集灰实验证明,两种修饰方法制备的PVDF膜均具有良好的防污自洁性能。     

Effect of surface metrology on the wettability of SiO2 nanoparticle coating

In this work, we fabricated an array of model hydrophobic surfaces with controlled roughness to establish a correlation between surface structure and observed hydrophobicity. SiO₂ nanoparticles of different sizes (7, 12, 14 and 40 nm) were layer-by-layer spin-coated on glass supports to study the effect of surface roughness on wettability evaluated by water contact angles. The hydrophobicity of one-layer structured surfaces improved with an increase in particle size. Deposition of bigger nanoparticles on top of smaller ones, generating double-layer structures, resulted in rougher surfaces with higher hydrophobicity. A strong correlation between the size ratio of deposited nanoparticle combinations and roughness was observed. Based on these correlations, it is now possible to tune surface roughness and subsequent wettability by controlling the sizes of the nanoparticle layers.     

One-step electrochemical machining of superhydrophobic surfaces on aluminum substrates

A superhydrophobic surface on an aluminum substrate was fabricated by one-step electrochemical machining using the sodium chloride (NaCl) aqueous solution containing fluoroalkylsilane as the electrolyte. The resulting superhydrophobic surfaces showed a static water contact angle of 166° and a tilting angle of about 1°. The morphological features and chemical compositions were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), electron probe micro-analyzer (EPMA), and Fourier-transform infrared spectrometer (FTIR). It shows that the binary micrometer–nanometer-scale rough structures and the low surface energy coating were present on the aluminum surfaces. The resulting surfaces have good properties of anti-adhesion and self-cleaning. The durability of the superhydrophobic surfaces on aluminum substrates was also investigated. This preparation method is advantageous as it does not require acid electrolyte or a separate process to lower the surface energy, uses simple steps, and is environmental friendly and highly efficient.     

On ice-releasing properties of rough hydrophobic coatings

In this work, ice repellency of rough hydrophobic coatings based on different materials and with different surface topographies is evaluated. The coatings were prepared either from a fluoropolymer incorporated with nanoparticles or by etching aluminum alloy substrate followed by further hydrophobization of the rough surface via an organosilane monolayer adsorbed from solution. This allowed comparing the ice-releasing performance of rough surfaces with high water contact angles (∼ 150-153°) and different dynamic hydrophobicities and mechanical properties. Artificially created glaze ice, similar to naturally occurring glaze, was accreted on the surfaces by spraying supercooled water microdroplets in a wind tunnel at subzero temperature. The ice adhesion strength was evaluated by spinning the samples in a centrifuge at constantly increasing speeds until ice detachment occurred. The results showed that, after several icing-deicing cycles, the more robust surfaces prepared by etching the aluminum substrate maintained their ice-releasing properties better, compared to their counterparts based on nanoparticle-incorporated fluoropolymer. The effect of the dynamic hydrophobicity of the coatings was also examined, clearly demonstrating that the surface with low dynamic hydrophobicity is not ice-repellent, although it demonstrates large values of water contact angle.     

挤压铸造6082铝合金的高温流变行为和变形激活能分析

目的 研究不同挤压铸造压力下所制备的6082铝合金的高温应力应变关系。方法 对100 MPa和50 MPa挤压铸造压力下制备的6082铝合金进行高温压缩实验,建立了相应的本构模型,并分析了挤压铸造压力和变形参数对流变行为和变形激活能的影响。结果 相同变形条件下,挤压铸造压力为100 MPa时,6082铝合金流变应力更高。当温度较高和应变速率较低时,两种不同的6082铝合金流变应力值差距明显缩小。挤压铸造6082铝合金的激活能随着变形温度和应变速率的增加而降低。结论 高挤压铸造压力下制备的6082铝合金变形激活能更大,变形更困难,但高温中低应变速率时,挤压铸造6082铝合金的变形难易程度相近。     

A universal method to fabricate Cu films with superhydrophobic and anti-corrosion properties

Multi-functional Cu films were fabricated by an improved electric brush-plating technique and subsequent immersion treatment in ethanol solution of stearic acid. The brush-plated Cu film exhibited unique lotus-like surface architectures, which endowed it with highly hydrophobicity, instead of metallic intrinsic hydrophilicity. After solution-immersion for certain time, the Cu films were gradually covered by a continuous net-like layer of copper stearate nano-sheets with low surface energy, which finally rendered them stable superhydrophobic and even self-cleaning. Electrochemical measurement revealed that anti-corrosion property of Cu is intimately linked with its surface wettability, and the superhydrophobicity indeed provides high corrosion resistance for Cu substrate in corrosion environment. This strategy can extend generally to other relevant metals.     

铝电解电容器用不同工艺腐蚀箔的对比研究

利用金相显微镜分析软质交流腐蚀箔、直交流腐蚀箔及硬质交流腐蚀箔的表面及断面蚀孔形貌,监测腐蚀箔恒电流阳极氧化过程中的升压曲线,并测试腐蚀箔阳极氧化后的比容、漏电流、抗拉强度及折弯次数.结果表明,软质交流腐蚀箔的蚀孔形貌呈灌木状;直-交流腐蚀箔的蚀孔呈乔木和灌木状分布,蚀孔中有部分大而稀疏的隧道孔,扩面倍率最小;而硬质交流腐蚀箔的蚀孔呈蜂窝状,孔洞细密,扩面倍率最大.直-交流腐蚀箔的漏电流最小,硬质交流腐蚀箔的抗拉强度及折弯次数最大.