具有超疏水性质的图案化Ag膜

以重氮树脂(DR)/聚丙烯酸(PAA)自组装膜的微图案作为模板, 通过DNA和聚二甲基二烯丙基氯化铵(PDDA)在模板上的层层沉积制备了图案化的DNA膜. 再在其中进行Ag的化学沉积得到图案化的Ag膜. 最后利用低表面能的十二烷基硫醇对Ag膜进行表面修饰, 制备了具有超疏水性质的图案化Ag膜. 其静态接触角达到约168°.     

基于水滴模板法的微纳复合超疏水结构制备的研究

利用粒子辅助水滴模板法的实施获得规则蜂窝状图案化多孔结构模板,并进一步利用聚二甲基硅氧烷(PDMS)复制转移技术获得表面具有微米尺寸蜂窝状突起阵列的反向图案化结构.以这种图案化突起结构作为微米尺寸所提供的微米级粗糙度为基础,设计了2种的简单的二次纳米结构的引入过程,最终实现了微米级阵列和纳米级粗糙度的复合.第一种方法借助银镜反应来实现纳米银结构的化学沉积,最终在PDMS阵列表面获得了致密的纳米银颗粒沉积层,并成功获得了表面接触角达166度的超疏水性质.第二种方法利用了聚电解质/二氧化硅粒子层层静电自组装的方法引入纳米结构,结果在仅仅进行了2个组装循环的条件下即可获得超疏水性质的表面复合结构.通过简单的实验设计试图提供一种基于水滴模板法的微纳复合超疏水结构的普适性制备方法.     

表面微图案化聚乳酸膜的制备及其细胞亲和性评价

利用溶剂-非溶剂法(SNS)制备表面具有微孔图案的聚乳酸(PLA)膜和聚苯乙烯(PS)膜,并以微孔PS膜为模板,构建表面具有微岛图案的PLA膜.以此为基础,对所制备的微图案表面对PLA膜亲/疏水性及成骨细胞粘附与增殖性能的影响进行研究.结果显示微图案的存在显著增强了PLA膜的表面疏水性(水接触角90°);成骨细胞在微图案表面具有良好的铺展性,其黏附数量明显高于光滑PLA膜,但细胞的生长曲线相对较平缓,显示微图案表面虽有利于细胞在PLA膜表面的粘附与铺展,但对促进细胞的增殖无贡献.     

超声辅助制备超疏水聚丙烯表面花瓣状微纳结构

超疏水微纳结构表面广泛应用于自清洁、防冰、抗菌、柔性传感等领域,但其制备工艺仍面临一定的挑战.以阳极氧化铝(AAO)膜为模板,采用热压印在聚丙烯(PP)表面成型了规整的纳米结构阵列.对纳米结构阵列进行超声处理,在超声空化作用下,PP表面纳米结构转变为类花瓣状微纳结构.结果表明,经超声处理后的微纳结构PP表面的接触角从152.3°上升至160.0°,滚动角从11.5°降低至1.8°,表面黏附力从75μN降低至38μN,呈现典型的超疏水低黏附特性且其自清洁效应明显.采用模板法与超声辅助相结合的方法制备超疏水微纳表面具有方便快捷、成本低廉、效果显著的优点,有望应用于工业生产领域.     

CaCO_3颗粒模板法制备聚合物超亲水/超疏水表面

以碳酸钙(CaCO3)颗粒层为模板,运用简单的热压和酸蚀刻相结合的方法制备聚合物超亲水/超疏水表面.首先在玻璃基底上均匀铺撒一层CaCO3颗粒,以此作为模板,通过热压线性低密度聚乙烯(LLDPE)使CaCO3颗粒均匀镶嵌在聚合物表面,获得了超亲水性质;进一步经酸蚀得到了具有微米和亚微米多孔结构的表面,其水滴静态接触角(WCA)可达(152.7±0.8)°,滚动角小于3°,具备超疏水性质.表面浸润性能和耐水压冲击性能研究表明该超疏水表面具有良好的稳定性和持久性.用同样工艺微模塑/酸蚀刻其它疏水性聚合物,得到类似结果.     

超疏水表面黏附性的研究进展

结合作者课题组的相关工作,简要地论述了超疏水表面固液黏附性的主要影响因素和评价标准,介绍了天然和人工仿生具有特殊黏附性超疏水表面的研究进展,包括超疏水高黏附表面、超疏水低黏附表面、可控黏附性超疏水表面、各向异性黏滞力超疏水表面、黏滞力响应性智能超疏水表面以及超亲/超疏水图案表面制备及运用.特别介绍了作者研究小组在仿生可控黏滞力超疏表面制备以及超亲/超疏水图案表面运用的研究.最后对具有特殊黏附性超疏表面的研究进行总结和展望.     

浸蚀多孔金属铝模板制备超亲水/超疏水镍阵列材料

本文论述了用一种新型的金属铝隧道孔模板制备较大面积的纳/微分级结构阵列材料。结合化学镀法在该高纯铝隧道孔模板中制备了具有微纳米阵列结构的金属镍薄膜。研究发现,制备的镍阵列薄膜材料表面呈现超亲水性,以低表面能氟硅烷修饰后,该表面变为超疏水性。     

超亲疏水图案改善阵列芯片质量

本文提出在超疏水表面加工超亲水圆点图案为阵列基底制作免疫蛋白微阵列, 从而减轻“咖啡环效应”, 改善阵列芯片质量.     

蜂窝状有序膜功能化研究进展*

水滴模板法是近年来引人瞩目的一种制备有序微结构材料的方法,所制备的蜂窝状有序膜在微容器和微反应器、图案化模板、细胞培养支架、光学材料、超疏水表面、分离膜等领域具有十分重要的应用前景。本文对蜂窝状有序膜功能化研究的最新进展进行了系统总结,详细介绍和分析了原位多层次自组装、表面接枝、生物活性分子固定、交联、模板法成膜以及表面填充等蜂窝状有序膜的功能化方法。     

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%.     

特殊浸润性表面的液滴凝结

以铝片为基底, 经电化学腐蚀和沸水处理制备了多级微纳米结构; 通过气相沉积和涂油分别制备了超疏水表面、 疏水超润滑(slippery)表面和亲水slippery表面; 探究了表面不同的特殊浸润性(超亲水、 超疏水、 疏水slippery和亲水slippery)对液滴凝结的影响. 结果表明, 超亲水表面的液滴凝结属于膜状冷凝, 超疏水表面和slippery表面的液滴凝结均属于滴状冷凝. 超疏水表面液滴合并时, 合并的液滴会不定向弹离表面. 疏水slippery表面和亲水slippery表面由于表面浸润性的不同导致液滴成核密度和液滴合并的差异, 亲水slippery表面凝结液滴的最大体积远大于疏水slippery表面凝结液滴的最大体积. 4种表面的雾气收集效率由大到小依次为亲水slippery表面>疏水slippery表面>超亲水表面>超疏水表面.     

Superhydrophilic/superhydrophobic surfaces fabricated by spark‐coating

In this study, the authors researched the preparations of superhydrophilic/superhydrophobic surfaces on commercial cup stock polyethylene coated papers by using sparked aluminum nanoparticles deposited on substrates through a sparking process. In this stage, the surface was porous and showed superhydrophilic properties. The samples were then annealed in air at various temperatures and some transformed to superhydrophobicity. It is well known that a suitable roughness in combination with low surface energy has been required to obtain superhydrophobic surfaces. Therefore, it is believed that during annealing process, when polyethylene is diffused from the substrate through the nanoparticle films and the superhydrophobic characteristics were created. The scanning electron microscope images showed that the film surfaces had a fluffy structure for both the as‐deposited and the annealed samples. However, the atomic force microscopy phase images showed completely different surface properties. Moreover, the X‐ray photoelectron spectroscopy spectra showed different surface chemical compositions. The experimental results revealed that the working temperature to produce superhydrophobic surfaces depended on the sparked film thickness. Furthermore, in order to prove the assumption explained above, glass and poly (methyl methacrylate) were also used as substrates.     

Wrinkled Graphene Monoliths as Superabsorbing Building Blocks for Superhydrophobic and Superhydrophilic Surfaces

Superhydrophobic and superhydrophilic surfaces are of great interest because of a large range of applications, for example, as antifogging and self‐cleaning coatings, as antibiofouling paints for boats, in metal refining, and for water–oil separation. An aqueous ink based on three‐dimensional graphene monoliths (Gr) can be used for constructing both superhydrophobic and superhydrophilic surfaces on arbitrary substrates with different surficial structures from the meso‐ to the macroscale. The surface wettability of a Gr‐coated surface mainly depends on which additional layers (air for a superhydrophobic surface and water for a superhydrophilic surface) are adsorbed on the surface of the graphene sheets. Switching a Gr‐coated surface between being superhydrophobic and superhydrophilic can thus be easily achieved by drying and prewetting with ethanol. The Gr‐based superhydrophobic membranes or films should have great potential as efficient separators for fast and gravity‐driven oil–water separation.     

Preparation of superhydrophobic silica films with honeycomb-like structure by emulsion method

Silica films with honeycomb-like structure were successfully obtained by emulsion method. Emulsion films prepared by the Dip-Withdrawing method were dried at 180 °C for 2 h and sintered at 500 °C, the films turned from superhydrophilic to superhydrophobic after being modified by octyltrimethoxysilane (OTMS) to form a self-assembled monolayer (SAM) with low surface energy. The surface structures and the thickness of the silica emulsion films were observed by scanning electron microscopy (SEM), and the results showed that the emulsion method had a similar effect to the phase separation one on producing the honeycomb-like structure that highly influenced the wettability of solid surface.     

A Simple,Low-cost Method to Fabricate Drag-reducing Coatings on a Macroscopic Model Ship

A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic copper coatings were characterized by means of scanning electron microscopy(SEM) and X-ray diffraction(XRD). Drag coefficient tests on surfaces with different wettability(superhydrophilic, hydrophilic, hydrophobic and superhydrophobic surfaces) showed that the as-prepared superhydrophobic surface exhibited a high remarkable drag reduction of 81% at a low speed of 1 mm/s. In the drag-reducing tests with model ship, the superhydrophobic coatings also exhibited around 16% drag reduction at a velocity of 0.3 m/s.     

Reversible wettability of a chemical vapor deposition prepared ZnO film between superhydrophobicity and superhydrophilicity

A superhydrophobic ZnO thin film was fabricated by the Au-catalyzed chemical vapor deposition method. The surface of the film exhibits hierarchical structure with nanostructures on sub-microstructures. The water contact angle (CA) was 164.3 degrees, turning into a superhydrophilic one (CA < 5 degrees) after UV illumination, which can be recovered through being placed in the dark or being heated. The film was attached tightly to the substrate, showing good stability and durability. The surface structures were characterized by scanning electron microscopy and atomic force microscopy.     

Superhydrofobic effect of hybrid organo-inorganic materials

Superhydrophobic films were obtained on the basis of sol–gel-derived titania or alumina/dodecylamine hybrid materials. It has been shown that wettability of surfaces of the inorganic oxides changes from superhydrophilic to superhydrophobic. For superhydrophobic materials, the surface roughness of the hybrid films on the basis of titania and alumina is 39 and 55 μm, respectively, and water contact angle is about 150°.     

Control of superhydrophilicity/superhydrophobicity using silicon nanowires via electroless etching method and fluorine carbon coatings

Surface roughness is promotive of increasing their hydrophilicity or hydrophobicity to the extreme according to the intrinsic wettability determined by the surface free energy characteristics of a base substrate. Top-down etched silicon nanowires are used to create superhydrophilic surfaces based on the hemiwicking phenomenon. Using fluorine carbon coatings, surfaces are converted from superhydrophilic to superhydrophobic to maintain the Cassie-Baxter state stability by reducing the surface free energy to a quarter compared with intrinsic silicon. We present the robust criteria by controlling the height of the nanoscale structures as a design parameter and design guidelines for superhydrophilic and superhydrophobic conditions. The morphology of the silicon nanowires is used to demonstrate their critical height exceeds several hundred nanometers for superhydrophilicity, and surpasses a micrometer for superhydrophobicity. Especially, SiNWs fabricated with a height of more than a micrometer provide an effective means of maintaining superhydrophilic (<10°) long-term stability.     

Superhydrophilic–superhydrophobic micropattern on TiO2 nanotube films by photocatalytic lithography

The present paper describes an unconventional approach to fabricate the superhydrophilic–superhydrophobic micropatterns on the TiO₂ nanotube structured film by photocatalytic lithography with a two-step process. At the first step, the superhydrophobic TiO₂ nanotube film is fabricated through electrochemical and self-assembled techniques. And at the second step, the superhydrophobic film is selectively exposed to UV light through a photomask to locally photocatalyse the organic monolayer assembled on the TiO₂ nanotube surface. The superhydrophilic–superhydrophobic micropatterns have thus been developed, as a novel template to fabricate a define micropatterned coating of nano octacalcium phosphate by electrochemical deposition. It is indicated that these combined processes reveal a very promising approach for constructing well-defined micropatterns of various functional materials.