超疏水性表面的制备及应用进展

近年来,受荷叶、水黾腿、壁虎脚等天然超疏水生物表面特性的启发,研究者们进行了大量仿生超疏水表面材料的制备及应用研究。超疏水性表面因其特殊的微纳分层结构,具有自清洁、防覆冰、防腐蚀、减阻等优异性能。本文阐述了表面润湿、疏水的基本机理,以及超疏水表面研究的理论基础,对超疏水表面制备的最新研究进展进行了综述,并揭示了研究中存在的问题。最后,介绍了超疏水表面在涂料、织物、防腐、抗菌及防雾等领域中的应用,展望了其未来的研究方向和前景。     

以砂纸为模板制作聚合物超疏水表面

报道了一种聚合物材料超疏水表面的简便制备方法. 以不同型号的金相砂纸为模板, 通过浇注成型或热压成型技术, 在聚合物表面形成不同粗糙度的结构. 接触角实验结果证明, 聚合物表面与水的接触角随着所用砂纸模板粗糙度的增加而加大, 其中粒度号为W7和W5砂纸制作的表面与水的接触角可超过150°, 显示出超疏水性质. 多种聚合物使用砂纸为模均可制备不同粗糙度及超疏水的表面, 本征接触角对复制表面浸润性的影响从Wenzel态到Cassie态而变小. 扫描电镜结果表明, 不规则形状的砂纸磨料颗粒构成了超疏水所需要的微纳米结构的模板.     

超疏水膜表面构造及构造控制研究进展

本文就表面构造对膜表面亲、疏水性的最新研究成果进行了概括,表面化学成分及化学结构聚集态是获得超疏水膜的基础,表面的形貌和微构造是维持超疏水性质的保障。利用含氟材料极低的表面能,将表面化学结构的聚集态,表面形貌微观构造及排列方式进行有机结合,将会获得理想的超疏水材料。     

仿生超疏水性表面的最新应用研究

近年来,除了荷叶表面,更多具有特殊润湿性的动植物表面同样受到关注。通过研究这些表面微观结构,人们成功地仿生制备出各种功能化超疏水表面,从而更好地满足工业中实际应用的需要。该综述简单地介绍了表面润湿的基本模型和最新的几种特殊表面结构,重点介绍近几年仿生超疏水表面应用的最新研究进展,主要包括超疏水表面在超疏油、表面润湿转换、外界刺激下的润湿行为调控、微流体、抗结冰等方面的应用。最后,对超疏水表面研究的未来发展进行了展望。     

纳米结构表面浸润性质的分子动力学研究

采用分子动力学方法研究了氩纳米液滴在铂金属及其模型固体表面的浸润现象,获得了液滴在平滑表面和三角纳米结构阵列表面的接触角和展布特性.研究表明,液滴与壁面的势能作用较强时,液滴与纳米结构表面为均匀浸润,但是由于迟滞效应,接触角受表面纳米结构的影响不明显;势能作用较弱时,纳米结构间隙中存在类似蒸汽的低密度相,液滴与纳米结构表面为非均匀浸润,接触角受纳米结构的影响而增大;表面纳米结构可以使表面具有超疏水性.     

三角紫叶酢浆草叶面的超疏水性

三角紫叶酢浆草叶面有很好的超疏水性,水滴在其表面的接触角约为150°,滚动角约为15°。研究发现,在三角紫叶酢浆草的叶面,分布有微纳米二元复合阶层结构的"星型"微凸体,微凸体之间有大量凹槽和空隙,复合阶层结构表面能吸附一层空气膜,液滴与其表面的接触是液、固、气的复合接触。此外,植物的叶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效应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示与借鉴。     

溶胶凝胶法制备仿生超疏水性薄膜

通过溶胶-凝胶(Sol-Gel)法和自组装(Self-assembled)制备了具有超疏水性的薄膜, 水滴在该薄膜上的平衡静态接触角为155°～157°, 滑动角为3°～5°. 通过扫描电子显微镜(SEM)观察薄膜微观表面, 发现该薄膜表面分布了双层结构(Binary structure)的微纳米粗糙度的微凸体, 上表层微米微凸体的平均直径为0. 2 μm, 下表层纳米微凸体的平均直径约为13 nm, 其分布与荷叶表面的结构极其相似. 用X射线光电子能谱(XPS)对薄膜表面元素进行了成分分析, 结果表明, 其表面存在大量的F, Cl等元素, 它能显著降低薄膜表面的表面能. 薄膜超疏水性的原因可能是, 通过硅片经溶胶粒子表面制备的薄膜具有合适的表面粗糙度, 再经过全氟辛基三氯甲硅烷(FOTMS)化学修饰后, 薄膜表面能进一步降低, 这两个条件的有机结合就使得薄膜产生了超疏水性.     

分子自组装法制备具有可控浸润性的铜表面简

通过简单浸泡的方法在铜基底上制备出了具有微纳米复合结构的氧化铜,再利用混合硫醇溶液[含HS(CH2)9CH3和 HS(CH2)11OH]对浸泡后的表面进行修饰,通过控制溶液中HS(CH2)11OH的浓度,制备出一系列具有不同浸润性的铜表面,实现表面从超疏水到超亲水的有效调控. 研究发现,表面浸润的可控性源于表面复合结构与不同化学组成的协同作用,微纳米复合结构的存在为表面浸润性的调节提供了必要的条件.     

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。     

花生叶表面的高黏附超疏水特性研究及其仿生制备

花生是一种常见的豆科作物.与低黏附超疏水的荷叶不同,花生叶表面同时具有超疏水和高黏附特性.水滴在花生叶表面的接触角为151±2°,显示出超疏水特性.此外,水滴可以牢固地附着在花生叶表面,将花生叶翻转90°甚至180°,水滴均不会从表面滚落,显示了良好的黏附性(黏附力超过80μN).研究发现,花生叶表面呈现微纳米多级结构,丘陵状微米结构表面具有无规则排列的纳米结构.花生叶表面特殊的微纳米多尺度结构是其表面呈现高黏附超疏水特性的关键因素.结合实验数据,对花生叶表面特殊浸润性机理进行了简要阐述.受此启发,利用聚二甲基硅氧烷复形得到了与花生叶表面微结构类似的高黏附疏水表面.本文以期为仿生制备高黏附超疏水表面提供新思路.     

Mimicking natural superhydrophobic surfaces and grasping the wetting process: a review on recent progress in preparing superhydrophobic surfaces

A typical superhydrophobic (ultrahydrophobic) surface can repel water droplets from wetting itself, and the contact angle of a water droplet resting on a superhydrophobic surface is greater than 150°, which means extremely low wettability is achievable on superhydrophobic surfaces. Many superhydrophobic surfaces (both manmade and natural) normally exhibit micro- or nanosized roughness as well as hierarchical structure, which somehow can influence the surface's water repellence. As the research into superhydrophobic surfaces goes deeper and wider, it is becoming more important to both academic fields and industrial applications. In this work, the most recent progress in preparing manmade superhydrophobic surfaces through a variety of methodologies, particularly within the past several years, and the fundamental theories of wetting phenomena related to superhydrophobic surfaces are reviewed. We also discuss the perspective of natural superhydrophobic surfaces utilized as mimicking models. The discussion focuses on how the superhydrophobic property is promoted on solid surfaces and emphasizes the effect of surface roughness and structure in particular. This review aims to enable researchers to perceive the inner principles of wetting phenomena and employ suitable methods for creation and modification of superhydrophobic surfaces.     

超疏水表面的研究进展

表面的浸润性是决定材料应用的一个重要性质,许多物理化学过程,如吸附、润滑、黏合、分散和摩擦等均与表面的浸润性密切相关.近年来,由于超疏水表面在自清洁表面、微流体系统和生物相容性等方面的潜在应用,有关超疏水表面的研究引起了极大的关注.本文综述了超疏水表面研究的新进展:简单介绍了表面浸润性的表征手段和影响因素,归纳了超疏水表面的制备方法和相关的理论分析,对超疏水表面研究的发展进行了展望.     

Synthesis and characterization of PMMA-based superhydrophobic surfaces

Recently, superhydrophobic surfaces are gaining much interest because they may be employed in a series of applications, spanning from the realization of self-cleaning surfaces to microfluidics to special water-impermeable tissues allowing perspiration. It is well-known that superhydrophobicity strictly depends on the combination of superficial micro- and nano-structures. Then, key factors in the process of surface synthesis are the parameters which will define the surface conformation. In this work, we deal with the fabrication of polymer-based superhydrophobic surfaces. We developed a new method to have a good control of the structure of the synthesised surface. A high stability of the superhydrophobic character during time was obtained. Moreover, the synthesis process is green and easily transferable to industry for large production.     

The wetting behavior of grafted hydrophilic acrylic monomers

The wetting behavior of vapor phase photografted hydrophilic acrylic monomers was evaluated by the three most commonly employed techniques, i.e., the captive bubble, the sessile drop, and the Wilhelmy plate technique. The measured contact angles and the overall wetting behavior were discussed in light of the non-ideal nature of these surfaces.It was found that the peculiar nature of hydrophilic grafted surfaces is carefully reflected in the experimentally measurable contact angles. While in the case of the captive bubble the hydrophilic and rough nature of these coatings prevent the bubble-surface contact, in the case of the sessile drop the measured contact angles follow the behavior predicted by contact angle hysteresis theories. Wilhelmy plate measurements, performed as sequential scanning loops, show velocity-dependent effects which are linked to the composition, morphology and mobility of the grafted surfaces.     

具有各向异性微纳米分级结构表面的构筑及其特殊浸润性的研究进展

自然界存在许多具有各向异性表面结构的生物,其表面表现出典型的对液体操控的方向性的差异。近年来,这种表面微结构的构筑引起了广泛的研究兴趣,已成为一个热点研究方向。天然的各向异性浸润表面是由复杂的异质微纳米结构组成,基于基础研究和应用推广的目的,可以将其简化为一些有序的方向性结构表面。本文介绍了现在应用广泛的几种各向异性微纳米分级结构的构筑方法,并对比分析其可行性。同时,文中还深入讨论了各向异性微纳米分级结构表面对于液体行为的调控。这种各向异性微纳米分级结构表面在微流体运输、微流控芯片等领域将有重要应用,也会对生命科学(比如生物芯片和重大疾病的早期诊断)、能源(比如电极材料的可控制备)和环境(比如污染物的分离及定向转化)等研究做出巨大的贡献。     

Recent Development of Durable and Self‐Healing Surfaces with Special Wettability

Artificial special wetting surfaces have drawn much interest due to their important applications in many fields. Nevertheless, tremendous challenges still remain for the fabrication of wetting surfaces with durable and self‐healing properties. Here, recent progress of durable, self‐healing wetting surfaces is highlighted by discussing the fabrications of several typical wetting surfaces including superhydrophobic surfaces, superamphiphobic surfaces, underwater superoleophobic surfaces, and high hydrophilic antifouling surfaces based on expertise and related research experience. To conclude, some perspectives on the future research and development of these special wetting surfaces are presented.

     

Surface Modification,Topographic Design and Applications of Superhydrophobic Systems

Superhydrophobic surfaces with expanded wetting behaviors, like tunable adhesion, hybrid surface hydrophobicity and smart hydrophobic switching have attracted increasing attention due to their broad applications. Herein, the construction methods, mechanisms and advanced applications of special superhydrophobicity are reviewed, and hydro/superhydrophobic modifications are categorized and discussed based on their surface chemistry, and topographic design. The formation and maintenance of special superhydrophobicity in the metastable state are also examined and explored. In addition, particular attention is paid to the use of special wettability in various applications, such as membrane distillation, droplet-based electricity generators and anti-fogging surfaces. Finally, the challenges for practical applications and future research directions are discussed.     

Lotus bioinspired superhydrophobic,self‐cleaning surfaces from hierarchically assembled templates

The super hydrophobic, self‐cleaning properties of natural species derive from the fine hierarchical topography evolved on their surfaces. Hierarchical architectures which are function‐mimetic of the lotus leaf are here described and created from multi‐scale hierarchical assembled templates. The first level of hierarchy was a micromachined dome structure template and the second level of hierarchy was added by layering a thin nanoporous membrane such as porous anodized alumina or an ion track etch membrane. The assembled templates were nanoimprinted by a single step process on thermoplastic films. The wetting angle of the surfaces reached a value of 160° and the self‐cleaning behavior was observed. The superhydrophobic behavior remained over 1 year after fabrication, which demonstrates the stability of these polymeric self‐cleaning topographies. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B. Polym. Phys. 2014 , 52, 603–609     

Superhydrophobic surfaces prepared by microstructuring of silicon using a femtosecond laser

We present a simple method for fabricating superhydrophobic silicon surfaces. The method consists of irradiating silicon wafers with femtosecond laser pulses and then coating the surfaces with a layer of fluoroalkylsilane molecules. The laser irradiation creates a surface morphology that exhibits structure on the micro- and nanoscale. By varying the laser fluence, we can tune the surface morphology and the wetting properties. We measured the static and dynamic contact angles for water and hexadecane on these surfaces. For water, the microstructured silicon surfaces yield contact angles higher than 160 degrees and negligible hysteresis. For hexadecane, the microstructuring leads to a transition from nonwetting to wetting.