化学/电化学腐蚀法快速制备超疏水金属铝

提出一种金属铝超疏水表面的快速制作方法. 先以化学腐蚀在铝表面形成微米级粗糙结构, 再通过电化学腐蚀构筑纳米结构, 在20 min内完成了超疏水表面所需粗糙结构的制备. 这种化学腐蚀/电化学腐蚀两步法比单独化学或电化学腐蚀方法在时间上缩短了1~2个数量级, 且不受铝材晶形限制, 同时电化学腐蚀所用电流密度也降低了1个数量级, 降低了对电源设备的要求, 可望大规模应用于工业生产和其它金属的超疏水表面制备.     

超疏水涂层表面粗糙结构对防覆冰性能的影响

结冰给交通、电力输送和航空等领域带来极大的安全隐患,研究防覆冰技术具有重要的应用价值。目前最具前景的防冰方法是涂层防冰,本文介绍了疏水涂层的构建方法,阐述了涂层疏水性和疏冰性之间的关系;重点论证了涂层表面粗糙结构对其防覆冰性能的影响,指出防覆冰涂层研发中存在的问题,并对该领域的发展趋势进行了分析和展望。     

SDBS/HCl化学刻蚀法制备具有纳米-微米混合结构的铝基超疏水表面

采用阴离子表面活性剂十二烷基苯磺酸钠(SDBS)作为辅助刻蚀剂, 利用盐酸刻蚀, 在铝基质的表面形成了纳米-微米混合的粗糙结构; 化学刻蚀后的粗糙表面经过1H,1H,2H,2H-全氟癸烷基三乙氧基硅烷(FDTES)的修饰, 形成了接触角大于160°的超疏水表面. 扫描电镜表征结果显示, 所得到的超疏水表面具有纳米-微米混合结构; 基于此, 利用气泡辅助刻蚀机理初步解释了二级混合结构产生的原因, 认为是坑刻蚀和位错刻蚀的共同作用导致了混合结构的产生. 此外, 不同pH和长时间暴露实验证明所制备的铝基超疏水表面具有良好的稳定性.     

Fabrication of Superhydrophobic Aluminum Plate by Surface Etching and Fluorosilane Modification

Superhydrophobic aluminum surfaces with a high water contact angle and low sliding angle on aluminum plate substrate were fabricated by means of surface etching with sodium hydroxide under ultrasonic bathing and then modification with fluorosilane. Scanning electron microscopy(SEM) showed a honeycomb-like structure on aluminum substrate surface after etching under ultrasonic bathing. And the surface was rendered from superhydrophilicity to superhydrophobicity after further modification with fluorosilane.     

Fabrication of Superhydrophobic Surface with Different Metal Films on Aluminum Alloy

A simple technique was developed for the fabrication of a superhydrophobic surface on the aluminum alloy sheets. Different hierarchical structures(Ag, Co, Ni and Zn) were formed on the aluminum surface by the galvanic replacement reactions. After the chemical modification of them with fluorination, the wettability of the surfaces was changed from superhydrophilicity to superhydrophobicity. Scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and water contact angle measurement were performed to characterize the morphological characteristic, chemical composition and superhydrophobicity of the surfaces. The as-prepared superhydrophobic surfaces showed a water contact angle as high as ca.160° and sliding angle as low as ca.3°. We hope the method to produce superhydrophobic surface can be used in many fields.     

热处理对超疏水性含氟丙烯酸酯共聚物膜表面性能的影响

以微乳液聚合法和溶液聚合法制备丙烯酸全氟烷基乙基酯和甲基丙烯酸甲酯的共聚物, 以1,1,2-三氟三氯乙烷为溶剂, 采用溶剂挥发成膜法直接制备出超疏水膜, 并研究120 ℃热处理对超疏水膜表面性能的影响. 对于用乳液聚合方法制备的超疏水膜, 随着热处理时间的延长, 滚动角表现出先逐渐增大直至完全不能滚动, 然后重新回复到极小滚动角的特殊变化过程, 而静态接触角只是略微减小, 完全不同于热处理对平滑的含氟聚合物表面接触角的影响. 扫描电镜结果显示, 聚合物膜表面形貌对应出现从微/纳复合粗糙结构到微孔粗化并重新形成微/纳复合多层粗糙结构的变化.     

水热法制备铝合金超疏水表面及电化学性能研究

在金属表面构建超疏水膜层是一种有效的防腐技术,本文采用水热处理和自组装技术在铝合金表面构建了超疏水膜层来提升铝合金的耐蚀性能. 通过对不同水热时间下制备的铝合金超疏水表面的电化学性能以及表面形貌进行测试分析,发现当水热反应时间为6 h时,制备的超疏水铝合金超疏水性和电化学性能达到最佳,接触角能达到155.5^o,在模拟海水溶液中保护效率能达到99.6%.     

喷砂-阳极氧化-氟化处理构筑铝合金超疏水表面

为研究复合法制备超疏水表面过程中主要工艺参数对表面形貌及超疏水性能的影响, 开发了一种喷砂-阳极氧化复合方法, 在铝合金表面构筑了微米-纳米二级结构, 经氟化处理后获得了超疏水特性. 结果表明, 喷砂处理在铝合金表面通过冲蚀的凹坑构筑出微米结构, 阳极氧化则在铝合金表面通过蜂窝状氧化膜构筑纳米结构. 但单纯构筑粗糙结构或单纯改变表面化学组成均不能在铝合金表面获得超疏水特性. 单纯的微米结构或纳米结构, 即使有低表面能聚合物修饰也不能获得超疏水特性. 只有微米-纳米二级结构和低表面能聚合物的协同作用, 才能有效构筑铝合金超疏水表面. 这种铝合金与水滴接触时, 形成的气阱可减小固体表面与水滴的接触面积, 降低表面与水滴间的热量交换, 从而减缓水分子的凝结, 提高铝合金的抗霜冻性. 同时, 气阱还可有效减缓海水的腐蚀, 提高铝合金的耐海水腐蚀性.     

铝合金表面超疏水涂层的制备及其耐蚀性能

基于含氟聚氨酯和纳米SiO₂的协同作用, 在铝合金表面成功制备了一层超疏水涂层. 用红外光谱、扫描电镜和电化学测试等技术对超疏水涂层进行了表征和分析. 红外光谱结果表明, 硅烷偶联剂(A1100)成功键合到纳米SiO₂表面. 扫描电镜和接触角测定仪对涂层的表面形貌表征结果表明, 涂层表面存在微米鄄亚微米尺度的粗糙结构, 接触角可达到156°, 滚动角小于5°. 电化学测试(交流阻抗和极化曲线)结果表明, 所得到的涂层极大地提高了铝合金的耐蚀性能.     

Preparation and Performance of Lignin-Based Multifunctional Superhydrophobic Coating

Superhydrophobic coatings have drawn much attention in recent years for their widespread potential applications. However, there are challenges to find a simple and cost-effective approach to prepare superhydrophobic materials and coatings using natural polymer. Herein, we prepared a kraft lignin-based superhydrophobic powder via modifying kraft lignin through 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) substitution reaction, and constructed superhydrophobic coatings by direct spraying the suspended PFDTES-Lignin powder on different substrates, including glass, wood, metal and paper. The prepared lignin-based coatings have excellent repellency to water, with a water contact angle of 164.7°, as well as good friction resistance, acid resistance, alkali resistance, salt resistance properties and quite good self-cleaning performance. After 30 cycles of sand friction or being stayed in 2 mol/L HCl, 0.25 mol/L NaOH and 2 mol/L NaCl solution for 30 min, the coatings still retain super hydrophobic capability, with contact angles higher than 150°. The superhydrophobic performance of PFDTES-Lignin coatings is mainly attributed to the constructed high surface roughness and the low surface energy afforded by modified lignin. This lignin-based polymer coating is low-cost, scalable, and has huge potential application in different fields, providing a simple way for the value-added utilization of kraft lignin.     

Preparation and Crystal Structure of Ni16Si9Al

The new ternary phase Ni₁₆Si₉Al was synthesized from the elements. The compound is formed in a presumably peritectoid reaction at 786 °C and has a narrow homogeneity range around the nominal composition. It adopts an orthorhombic structure (space group Cmcm) related to Ni₃Si₂. It was found, that one particular position is occupied by aluminum together with silicon causing slight splitting and thus leading to a local symmetry break in the structure. Both, Ni₁₆Si₉Al and Ni₃Si₂, show related structural motifs and can be described by a combination of flat layers and puckered slabs with interatomic distances indicating covalent interactions between the atoms.     

铝合金表面用化学刻蚀和阳极氧化法制备的超疏水膜层的耐蚀性能

通过化学刻蚀和阳极氧化在AA2024铝合金表面制备超疏水表面。当化学刻蚀时间超过3 min时,表面在很宽pH值范围内显示出水静态接触角大于150°。SEM和AFM照片表明化学刻蚀时间决定了试样表面形貌和粗糙度。FTIR用来研究氟硅烷(G502)与AA2024表面的结合。结果说明FAS(氟硅烷)分子与铝合金表面的三氧化二铝发生反应,并在阳极氧化膜层表面展示出优异的结合性能。超疏水表面的耐腐蚀性能通过在质量分数为3.5%的NaCl溶液中进行动电位极化和交流阻抗(EIS)测试。电化学测试结果和等效电路模型显示出超疏水表面显著改善抗腐蚀性能。     

超疏水性材料表面的制备、应用和相关理论研究的新进展

文章总结了Wenzel方程、Cassie方程及一种具有极高精确度的,可方便测出固体表面上液滴前进角和后退角的测试方法等超疏水表面的最新理论研究成果;回顾了溶胶凝胶法、化学修饰法、喷涂法、液相法、化学蚀刻法、水热法、微相分离法、原位聚合法、静电纺丝法、阳极氧化法等近几年出现的超疏水表面的制备方法;介绍了在微物质能量、生物医学、光学、燃料以及电池应用等领域超疏水表面的最新功能性的应用。最后,客观地展望了超疏水表面制备及理论研究的发展方向。     

超疏水多孔硅的制备及表面稳定性

在加热条件下采用氢化硅烷化反应对多孔硅表面进行改性,通过扫描电子显微镜、红外光谱及元素分析等手段表征了多孔硅改性前后的结构和组成,研究了不同反应时间对其性能的影响.结果表明,反应3 h后制得了超疏水表面的多孔硅,其在碱性及空气环境中具有良好的稳定性.     

三聚磷酸铝缓蚀性能的EIS研究(英文)

利用电化学阻抗谱研究了方解石及三聚磷酸铝环氧涂层的耐蚀性能 ,并提出了它们的作用机理 .结果表明 ,方解石只起体质颜料作用 ,不具备缓蚀性能 ;而三聚磷酸铝因在钢基表面作用形成致密的保护膜则表现出优良的缓蚀性能 .     

超疏水低粘着铜表面制备及其防覆冰性能

用喷砂处理在铜片表面形成微米级丘陵状凹坑,再用表面氧化处理在铜片表面制备菊花花瓣状CuO纳米片.通过喷砂-表面氧化处理在铜片表面成功构建了微米-纳米复合结构,这种表面氟化后与水滴的接触角高达161°,滚动角低至1°,显示出优异的超疏水性和很低的粘着性.低温下,这种表面与水滴间的热量交换较小,水滴不易凝结,有效地提高了抗结霜性.抗结霜性良好的超疏水铜有望在热交换器或低温运行设备等领域获得应用,这种简便的超疏水铜表面的制备方法也给其它工程材料超疏水表面的工业化制备提供了一个思路.     

铝合金表面原位自组装超疏水膜层的制备及耐蚀性能

采用阳极氧化法在铝合金表面原位构造粗糙结构, 经表面自组装硅氧烷后得到超疏水自清洁表面, 与水滴的接触角最大可达157.5°±2.0°, 接触角滞后小于3°. 通过傅立叶变换红外(FT-IR)光谱分析仪、场发射扫描电子显微镜(FE-SEM)、能谱仪(EDS)、原子力显微镜(AFM)和接触角测试对阳极氧化电流密度、硅氧烷溶液中水的含量和自组装时间等参数进行了分析, 并得到制备超疏水自清洁表面的最优工艺参数. FE-SEM及AFM的测试结果表明, 由自组装硅氧烷膜层的无序性形成的纳米结构和阳极氧化构造的微米级粗糙结构与硅氧烷膜层的低表面能的协同作用构成了稳定的超疏水表面. 电化学测试(动电位极化)的结果表明, 原位自组装超疏水膜层极大地提高了铝合金的耐蚀性.     

Cyclopentanolates of Aluminum Hydride/Aluminum Chloride forming Aluminum‐Oxygen‐Hetero‐Cages and Mixed Coordination Oligomers

Lithium aluminum hydride combined with different amounts of aluminum chloride react with cyclopentanol under the formation of compounds with aluminum‐oxygen scaffolds and hydrogen or chlorine as terminating substituents at aluminum and cyclopentyl at the oxygen atoms. H₆Al₄(OC₅H₉)₆ and Cl₆Al₄(OC₅H₉)₆, both displaying a central aluminum atom almost octahedrally coordinated by oxygen atoms of the cyclopentanolates with three AlH₂ or AlCl₂ entities bridging three oxygen edges were isolated and fully characterized. The compound dihydrido aluminum cyclopentanolate was isolated together with chloro‐hydrido aluminum cyclo‐pentanolate as a 6:2 aggregate, [H₂Al(OC₅H₉)]₆[H(Cl)Al(OC₅H₉)]₂, displaying alcoholate and hydride bridges in the crystal. Structural isomers of this compound were found in the solid. Mono‐hydrides could be isolated in the form of H₅Al₅(O)(OC₅H₉)₈ * OC₄H₁₀ and in the form of a hydride/chloride H_4.5Cl_0.5Al₅(O)(OC₅H₉)₈ * OC₄H₁₀, which is a 1:1 mixture of H₅Al₅(O)(OC₅H₉)₈ with H₄ClAl₅(O)(OC₅H₉)₈ in the crystal. In both compounds an oxygen atom is in the center of an Al₅ square pyramid. While in the first case the aluminum atom situated at the top of the pyramid has a hydride ligand, in the second case the ligand is a chloride.     

Synthesis and Crystal Structures of Aluminum,Gallium and Indium Complexes with Chelating Me2Si(NPh)22– Ligands

The reaction of ECl₃ (E = Al, Ga) with two equivalentsof Li₂Me₂Si(NPh)₂ (in diethyl ether/n‐hexane) leads to the formation of bis‐chelate complexes [Li(OEt₂)₃][E{Me₂Si(NPh)₂}₂] (E = Al ( 1 ), Ga ( 2 )). Compounds 1 and 2 crystallize isotypically in the monoclinic system with a = 1136.42(6), b = 3267.9(1), c = 1360.37(8) pm, β = 94.320(7)° for 1 and a = 1140.88(6), b = 3261.7(2), c = 1360.20(8) pm, β = 94.641(7)° for 2 . Both the compounds display a distorted tetrahedral coordination of the central metal atom to give a spirocyclic EN₄Si₂ core. The Al–N bond lengths are in the range of186.5–186.9 pm and for the Ga–N distances values between 192.3and 193.1 pm are observed. Treatment of InCl₃ with three equivalents of Li₂Me₂Si(NPh)₂ yields the tris‐chelate [{Li(OEt₂)}₃In{Me₂Si(NPh₂)}₃] 3 . Compound 3 crystallizes in the trigonal crystal system , space group R$\bar{3}$ c with a = 1852.4(1), and c = 3300.2(2) pm. The central indium atom is coordinated by threeMe₂Si(NPh)₂^2– ligands in a distorted octahedral arrangement withIn–N bond lengths of 230.8 pm.     

反应离子刻蚀和自组装分子膜构建硅基底疏水与超疏水表面

采用反应离子刻蚀技术在Si(100)表面加工微米级圆柱阵列, 采用自组装技术分别制备了3种硅烷自组装分子膜. 结果表明, 采用反应离子刻蚀构建出的4种微米级圆柱阵列结构规整, 其直径为5 μm, 高度为10 μm, 间距为15~45 μm. 沉积自组装分子膜后, 试样表面的水接触角显著增大, 其中沉积1H,1H,2H,2H-全氟癸基三氯硅烷(FDTS)自组装分子膜接触角最大, 1H,1H,2H,2H-全氟辛烷基三氯硅烷(FOTS)次之, 三氯十八硅烷(OTS)最小. 测得的接触角大于150°时接近Cassie方程计算的接触角, 而小于150°时接近Wenzel方程计算的接触角. 改变圆柱阵列的间距和选择不同的自组装分子膜, 可以控制表面接触角的大小. 原子力显微镜(AFM)观测结果显示, 沉积自组装分子膜可以产生纳米级的团簇. 由微米级圆柱阵列和纳米级自组装分子膜构成的表面结构使Si试样表面接触角最大可达156.0°.