阵列聚合物纳米柱膜的超疏水性研究

Wettability is a very important property governed by both the chemical composition and the geometrical structure of solid surfaces. Super-hydrophobic surface[with water contact angle(CA) larger than 150°] have been extensively investigated due to their importance for industrial applications. In the present study, we describe a rather simple method for synthesizing separated alignments of polymer nanopole films, which has super-hydrophobic property with water a contact angle as high as 152.0°. Nanostructures that induce the large fraction of air on the surface cause this unique property.

射频等离子体改性PTFE表面液滴撞击接触起电对润湿性的影响

液滴撞击固体表面是自然界的常见现象,研究超疏水表面的液滴撞击对其润湿性的影响,对于超疏水性材料的潜在应用具有重要的科学意义。采用3、10、20 min氧等离子体处理(OPT)和1 min八氟环丁烷等离子体聚合沉积(PPD)的等离子体方法改性聚四氟乙烯(PTFE)表面,获得具有不同尺寸和间距的微/纳米锥的超疏水PTFE表面,研究射频等离子体改性PTFE表面的液滴静态接触角、滚动角及液滴撞击动力学行为,分析在不同个数液滴撞击后PTFE表面的润湿性和液滴撞击行为变化,确定PTFE表面液滴撞击起电效应的影响机制。结果表明:通过1~9个液滴撞击后,PTFE表面的静态接触角随撞击液滴数量增加而减小,导致静态接触角低于150°;液滴滚动角随撞击液滴数量增加而增大,造成液滴滚动角高于10°。撞击液滴的接触时间随撞击液滴数量增加而增大,回弹系数随撞击液滴数量增加而减小。随撞击液滴数量增加,回弹液滴的正电荷和PTFE表面的负电压增大,PTFE表面的负电荷对液滴产生强吸引作用,导致低粘附超疏水性被破坏。3 min OPT和1 min PPD改性PTFE表面的纳米锥间距小,密度大,表面负电荷量增加明显,造成PTFE表面的疏水性降低的程度最显著。研究结果可为改善超疏水稳定性的表面织构设计提供理论依据。

等离子体纳米织构化聚合物表面的液滴蒸发机制

超疏水性表面的微纳结构改变极大影响了液体蒸发行为,在超疏水性材料工程应用方面具有重要研究价值。采用氧等离子体处理(OPT)和八氟环丁烷等离子体聚合沉积(FPD)的两步等离子体纳米织构化法在聚丙烯表面制备纳米线和纳米锥结构,研究具有不同纳米织构聚丙烯超疏水性表面的去离子水滴在30℃和60℃温度下的蒸发行为,并对其蒸发机制进行讨论和分析。结果表明:液滴在超疏水性表面总蒸发时间随FPD时间的增加变短。液滴蒸发初期,液滴在聚丙烯表面处于Cassie态,此时主要传热方式为聚丙烯表面通过气体与液滴间接传热,液滴均匀蒸发,蒸发模式为恒定接触角(CCA)模式;随蒸发时间增加,液滴在表面的浸润状态依次转变为Marmur态和Wenzel态,主要传热方式变为聚丙烯表面与液滴直接传热,液滴蒸发加快,蒸发模式转变为混合(Mixed)模式。聚丙烯表面纳米织构的尺寸增大和团簇增加导致液滴与超疏水性表面之间的气相占比减少,造成聚丙烯表面与液滴直接传热加强,促进了液滴从CCA到Mixed的蒸发模式转变。

聚氟硅氧烷处理的微纳表面水流减阻研究

本文成功制备了聚氟硅氧烷处理的微纳结构表面,并研究了其宏观水流减阻特性。首先,采用包覆工艺对粉煤灰球形微珠进行表面纳米化处理,制备出微纳结构复合微珠颗粒,并利用聚氟硅氧烷对复合微珠进行表面疏水处理;然后以硅橡胶为黏接剂将表面疏水化的复合微珠涂覆于槽道表面,制备出宏观尺度的超疏水性表面槽道。研究表明:聚氟硅氧烷处理的微纳结构粉煤灰复合微珠制备的宏观尺度超疏水性表面槽道与相同尺寸的普通表面槽道相比,当雷诺数Re<1500时,层流减阻为22.6%,而Re>1500时,湍流减阻达到76.5%。

Inhibiting Ice Accumulation on Conductors by Using Sheath Treated with Super-hydrophobic Surfaces

Ice accumulation on transmission lines often leads to great damage to power systems.Super-hydrophobic surfaces are proposed to inhibit ice accumulation on electrical power equipment.A novel anti-icing method was presented for conductors with super-hydrophobic sleeves.The super-hydrophobic sleeves were prepared by applying polydimethylsiloxane(PDMS) and nano-silica hybrid coating on the outer surface of polyethylen terephthalate(PET) sleeves.Hydrophobicity and ice adhesion strength of the super-hydrophobic surface were investigated.Ice accumulation experiments were carried out on ordinary conductors,super-hydrophobic coated conductors,PET sleeve-covered conductors,and super-hydrophobic PET sleeve-covered conductors.Ice accumulation morphology,accumulated ice weight,and the icicle length of these four types of conductors were studied and analyzed.At the end of the 3 h ice accumulation experiment,the ice weight and icicle length on the conductor with super-hydrophobic PET sleeve was only approximately one tenth and one seventh of that on the untreated conductor respectively.Furthermore,the water contact angles of super-hydrophobic coated aluminum surface and super-hydrophobic coated PET sleeve were about 163o in average.The results indicate that the super-hydrophobic coating is effective in inhibiting ice accumulation on conductors.However,the use of a super-hydrophobic PET sleeve is a significantly more effective method,comparing with the application of a super-hydrophobic coating directly on the conductor.

Fabrication of Super Hydrophobic Surfaces on Copper by Solution-immersion

Super hydrophobic copper wafer was prepared by means of solution immersion and surface self-assembly methods. Different immersion conditions were explored for the best hydrophobic surface. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and water contact angle measurements were used to investigate the morphologies, microstructures, chemical compositions and hydrophobicity of the produced films on copper substrates, respectively. Results show that the super hydrophobic surface is composed of micro structure of Cu 7 S 4 . The films present a high water contact angle larger than 150°, a low sliding angle less than 3°, good abrasion resistance and storage stability. The molecular dynamics simulation confirms that N-dodecyl mercaptan molecules link up with Cu 7 S 4 admirably, compared with Cu, which contributes to the stable super hydrophobic surface.

专利

专利名称：超疏水性粉体、具有超疏水性表面的结构体及这些的制造方法 专利申请号：CN200980131390．3左公开导CN102119245A 申请日：2009．07．27公开日：2011．07．06 申请人：日本财团法人川村理化学研究所；DIC株式会社 本发明涉及一种以二氧化硅作为主成分的粉体，在该粉体的表面水的接触角为150°以上的超疏水性粉体的制造方法，以及使用该粉体的具有超疏水性表面的结构体．详细来说，提供一种向位于有机物的聚合物与无机物二氧化硅以纳米级复合而成的有机无机复合纳米纤维的缔合体表面的二氧化硅中、或煅烧该有机无机复合纳米纤维并除去聚合物后的二氧化硅中导人疏水性基团，从而将由该缔合体形成的粉体制成超疏水性的制法、以该制法得到的超疏水性粉体、以及将其固定在固体基材表面而成的具有超疏水性表面的结构体．

Water droplet impact on superhydrophobic surfaces with microstructures and hierarchical roughness

Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically studied.Experimental data shows that the critical impact velocity induced wetting transition of droplet on the superhydrophobic surfaces is strongly determined by the perimeter of single micropillar,the space between the repeat pillars and the advancing contact angle of the sidewall of the micropillars.The proposed model agrees well with the experimental results,and clarifies that the underlying mechanism which is responsible for the superhydrophobic surface with hierarchical roughness could sustain a higher liquid pressure than the surfaces with microstructures.

Single-step fabrication of bionic-superhydrophobic surface using reciprocating-type high-speed wire cut electrical discharge machining

In this work, bionic-superhydrophobic surfaces on aluminum alloy 5083 are fabricated by reciprocatingtype high-speed wire cut electrical discharge machining based on the hydrophobic property of the rice leaf. Submillimeter-scale rectangular grooves are processed on the surfaces. The superhydrophobic surface has shown a static contact angle of 158°, which is similar to the rice leaf. The morphological features are characterized by scanning electron microscopy, showing that the craters and bumps are uniformly distributed on the surfaces of the rectangular grooves with porous nanostructures. The method proposed in this work has the advantages of using only one step,requiring no further procedure to lower the surface energy and processing a large-area surface efficiently.

Robust superhydrophobicity of hierarchical ZnO hollow microspheres fabricated by two-step self-assembly

Superhydrophobic 和 superhydrophilic 表面广泛地为工业应用由于他们的重要性被调查了。然而， superhydrophobic 表面是很敏感的加热，这被报导了，紫外(紫外) 轻、电的潜力，它防碍他们的长期的耐久性。在这研究，我们介绍一条新奇途径完成柔韧的 superhydrophobic 由设计定义建筑学的复杂 nanostructures 的薄电影。分别地，有在 mesoporous nanoball 堵住的 1D nanowire 网络， 2D nanosheet 栈，和 3D 的形态学的控制成分体系结构的 ZnO 空 microspheres 的一个家庭经由一个二拍子的圆舞被综合自己组装途径，有特殊设计的结构的 oligomers 或成分 nanostructures 在哪儿，首先从表面活化剂模板形成，然后进一步由第二合作表面活化剂的增加集合了进复杂形态学。由二拍子的圆舞组成的薄电影综合了有不同体系结构的 ZnO 空 microspheres 与 150 猠杵敧瑳 ? 的接触角度介绍了 superhydrophobicities ? 漠楲慧業愠 ?? 慣摮摩瑡 ?

Evaporating behaviors of water droplet on superhydrophobic surface

We investigated the dynamic evaporating behaviors of water droplet on superhydrophobic surfaces with micropillars.Our experimental data showed that receding contact angles of the water droplet increased with the decreasing of the scale of the micropillars during evaporation,even though the solid area fractions of the microstructured substrates remained constant.We also experimentally found that the critical contact diameters of the transition between the Cassie-Baxter and Wenzel states are affected not only by the geometrical parameters of the microstructures,but also by the initial volume of the water droplet.The measured critical pressure is consistent with the theoretical model,which validated the pressure-induced impalement mechanism for the wetting state transition.

Fabrication of superhydrophobic AAO-Ag multilayer mimicking dragonfly wings

Inspired by the co-coupling of the non-smooth structure and the waxy layer inducing the hydrophobicity of dragonfly wing surface,we developed a simple and versatile method to fabricate a superhydrophobic surface with the dragonfly wing structures.In this work,Ag nanorods grew on highly ordered anodic aluminum oxide(AAO) surface via a galvanic reduction approach.Then the AAO-Ag multilayer was fabricated.Furthermore,the surface free energy of AAO-Ag multilayer was reduced by modifying with perfluorodecanethiol.The modified AAO-Ag multilayer was superhydrophobic and the static contact angle reached as high as 168°.X-ray photoelectron spectra(XPS) were used to characterize the chemical structure of the obtained products.The morphologies of AAO-Ag multilayer was similar to microstructure of dragonfly wing surface and presented hierarchical rough structure.The results showed that the co-coupling of the rough structure and low surface free energy induced the superhydrophobic performance of the AAO-Ag multilayer surface.

Titanium Oxide Intelligent "Optical Switch" Surface

Bio-mimic super-hydrophobic and super-hydrophilic switches were highly concerned because of their extensive application perspectives in gene transfers, non-loss liquid transportation, micro fluid, gene chips, and

Inspiration Was Just Floating in the Natural Air-Research in Key Laboratory of Organic Solids, Institute of Chemistry of CAS

Sponsored by NSFC, CAS, and Ministry of Science and Technology, the Key Lab of Organic Solids in Institute of Chemistry of CAS developed tungsten oxide 'light switch' membrane, which has wetting and discolorment abilities. Thereafter, the team progressed in the research of preparation for stable metal hydrophobic surface, and successfully developed metal hydrophobic membrane. As they say, 'Since the establishment of our lab in 1999, our achievements come from inspirations floating in the natural air'.

弹跳的水滴能产生高效动力

犹他州普罗沃市杨百翰大学实验室机械工程教授Julie Crockett对水像球一样跳跃和沿斜坡滚动的情况进行了分析。Crockett和她的同事Dan Maynes制造出一种具有超疏水性非常难打湿的斜坡通道。“我们的研究目的是帮助得到理想的超疏水性表面，”Crockett说。“通过研究不同表面的特殊性能，我们能更好的确定哪种表面更适合于哪种应用。”