疏水型SiO2气凝胶薄膜的制备

二氧化硅气凝胶薄膜是一种应用广泛的功能材料.本文采用sol-gel技术和dip-coating镀膜工艺,在玻璃表面上形成了SiO2气凝胶薄膜,对SiO2膜层进行表面修饰处理,得到了疏水型SiO2气凝胶薄膜.研究了催化剂与老化过程对薄膜物性的影响.结果表明该疏水膜能使玻璃表面与水的接触角由50°提高至125°,有明显的疏水效果.     

氟化聚乙烯醇/SiO_2超疏水薄膜的制备及性能

以亲水性高分子聚乙烯醇(PVA)为基体,二氧化硅(SiO_2)纳米颗粒为无机填料,旋涂在玻璃表面后的PVA/SiO_2再经十七氟癸基三甲氧基硅烷(C_(13)H_(13)F_(17)O_3Si,FAS)修饰,制备了具有超疏水性能的PVA/SiO_2-FAS薄膜。考察了PVA与SiO_2复合的比例及FAS修饰对膜疏水性的影响。用傅里叶变换红外光谱、X射线能谱和扫描电子显微镜分别对超疏水表面进行了结构分析和形貌表征,用接触角测量仪观察了水滴在膜表面的润湿性。结果显示,当PVA/SiO_2体积比为1∶5时,氟化PVA/SiO_2膜表面具有较好的超疏水功能,静态接触角可达151.24°,滚动角约为4°。这主要是膜表面含有低表面能氟原子及具有纳米粗糙结构共同作用的结果。     

木材仿生超疏水功能化修饰研究进展

超疏水现象广泛存在自然界中,由于具有特殊的疏水及自清洁性能,在材料仿生构建领域引起了国内外学者的高度关注。木材仿生超疏水功能化修饰,能有效隔离水分与木材的接触,在木材及其产品室外长久利用、复杂高湿环境利用方面意义重大。从自然界超疏水现象与疏水理论基础出发,重点综述了木材超疏水仿生构建的主要方法,并对超疏水木材的性能进行探讨,提出了木材超疏水处理亟待解决的难题。     

玻璃表面超疏水性薄膜制备

采用溶胶-凝胶法,以三甲基氯硅烷、氢氟硅酸和水为先驱体,在玻璃基片上用提拉法制备出一种含有-CF3强疏水性基团的氟硅烷薄膜.通过红外光谱和扫描电镜对薄膜结构和表面形貌进行了表征和观察.并用接触角测定仪三甲基氯硅烷和氢氟硅酸在不同摩尔配比下薄膜疏水性能.结果表明该薄膜具有高度交联的不规则球状表面结构.当三甲基氯硅烷和氢氟硅酸的摩尔比为2.5:1时,薄膜具有超疏水性,对水滴的表面接触角可达156°.     

金属锌表面超疏水薄膜的制备及其摩擦学性能

通过简单两步法在金属锌表面构筑超疏水薄膜, 锌片首先经N,N-二甲基甲酰胺(DMF)处理在表面构筑微纳结构薄膜, 然后在表面覆盖硬脂酸薄膜以实现超疏水. 采用扫描电子显微镜, 傅里叶红外光谱仪和接触角测量仪等手段表征了超疏水表面的形成机制和表面形貌, 并利用微纳米摩擦磨损试验机研究了超疏水薄膜的减摩耐磨特性. 研究结果发现, 在锌表面形成了一层纳米棒状结构的超疏水薄膜, 水的接触角可达155^o. 超疏水薄膜具有明显的减摩和耐磨特性, 这可归因于DMF处理导致的表面微织构化效应以及脂肪酸自组装薄膜的纳米润滑效应.     

耐久性超疏水表面的研究进展

介绍了超疏水表面的性质并指出目前超疏水表面存在耐久性的缺陷,阻碍了其实际应用和推广。对目前制备耐久性超疏水表面的研究进展进行了综述,列出了现今耐久性超疏水表面的应用,指出目前耐久性超疏水存在检测及标准不统一、理论支持不足、制备条件苛刻等问题,并就这些问题对未来耐久性超疏水研究做出了展望。     

纳米SiO2层层组装构建超疏水表面

采用500nm和20nm的SiO2粒子,通过表面改性使其分别具有氨基和环氧基,利用氨基和环氧基的反应使500nm和20nm的SiO2粒子形成复合粒子,制备了具有微纳米双尺寸粗糙度的超疏水表面。通过扫描电镜和接触角测量仪对超疏水表面的结构及性能进行了表征,发现其具有微纳米二级结构,测得其静态接触角达到156°,滚动角小于3°,并且能够承受240℃的高温而保持其超疏水性能,为超疏水表面的制备提供了一种新的方法。     

一种提高超疏水木材机械稳定性的方法

超疏水表面稳定性、耐久性的提升,对于其是否能达到商业应用的要求有着至关重要的作用。本文将聚乙烯醇(PVA)与二氧化硅(SiO2)复合,通过滴涂法在木材表面形成一层有机-无机复合薄膜,之后对薄膜进行疏水改性,制得了一种机械稳健性较好的超疏水木材。所制得的木材有很好的防水性、较低的滚动角和较好的机械稳定性。     

仿生超疏水表面研究进展

对植物叶表面的研究结果表明:微米与纳米相结合的结构可以产生较大的接触角和较小的滚动角.表面化学组成与粗糙结构相结合成为仿生超疏水表面的重要特点.本文在总结近年来仿生超疏水表面的最新研究成果的基础上,着重分析和讨论了仿生超疏水表面的物理机制、制备方法、超亲水与超疏水的转换,并探讨了这一领域的发展方向.     

超疏水表面材料

首先介绍了荷叶效应和超疏水表面,重点介绍了超疏水表面的生成机理和目前已在纺织、材料、建筑等领域投入使用的性能优异的超疏水表面材料,并提出了最新的展望。     

One-step synthesis of unique silica particles for the fabrication of bionic and stably superhydrophobic coatings on wood surface

The silica particles with unique morphology and hydrophobicity have been synthesized via a drop-coating method. After this one-step sol–gel process, silica particles as well as polystyrene were employed in the bionic and stably superhydrophobic coatings on wood surface (with water contact angle of 153 ± 1° and sliding angle less than 5 ± 0.5°). Scanning electron microscopic (SEM) studies revealed that the composite coatings possess two dimensional hierarchical structures comprising of micron scale papilla and submicron scale granules. The synergistic effect of micron/submicron binary structure and low surface energy layer was responsible for the superhydrophobicity of wood surface. Moreover, the chemical and mechanical stabilities of treated wood have been investigated as well, and the results show that the product possesses superhydrophobic property in a wide extent, such as pure water, corrosive water under both acidic and basic conditions, and some common organic solvents. More importantly, it will offer an opportunity to extend the range of practical applications for wood resources.     

ZnO/E-51复合涂料上超疏水表面的制备

采用ZnO和环氧树脂机械搅拌制备ZnO/E-51复合涂料,通过真空袋压、室温固化成型,再通过化学刻蚀与表面修饰,在ZnO/E-51复合涂料上制备出超疏水表面。采用扫描电镜和动/静态接触角分析仪,表征表面的形貌和疏水性。结果表明化学刻蚀在复合涂料表面构建了具有微-纳米尺度二元粗糙结构;采用1%(质量分数)的硬脂酸修饰,可改变复合涂料表面微-纳米尺度二元粗糙结构,影响表面的疏水性能,当修饰时间为30min时,其表面与水的平均接触角最高达152.21°。     

Fabrication of Au/SiO2 Nanocomposite Films by Self-Assembly Multilayer Method

Gold colloid was prepared by chemical reduction of hydrogen tetrachloroaurate, polyelectrolyte/gold nanoparticle/silica nanoparticie composite films were fabricated via an electrostatic self-assembly multilayer method, and composite films of gold nanoparticle dispersed in silica matrix were formed by heat-treating the polyelectrolyte/gold nanoparticle/silica nanoparticle composite films to eliminate the polyelectrolyte. The obtained composite films were investigated with UV-vis, TEM, AFM and XRD. The results show that the self-assembly multilayer method is a promising process to produce composite films of gold nanoparticle-dispersed in organic and/or inorganic matrixes.     

A novel method to prepare a microflower-like superhydrophobic epoxy resin surface

A novel microflower-like superhydrophobic epoxy resin surface was obtained using a novel method. The water contact angle and sliding angle of the superhydrophobic epoxy resin surface was 158 ± 1.7° and 3°, respectively. The as-prepared microflower-like superhydrophobic epoxy resin surface also showed superhydrophobic property in the pH range of 3–14. After being stored in ambient environment for one month, no decrease in water contact angle was observed.     

Fabrication of raspberry-like superhydrophobic hollow silica particles

Raspberry-like superhydrophobic hollow silica particles were prepared through a sacrificial polymer template method. The Stöber method was adopted to coat silica onto the surface of cationic polymethylmethacrylate(PMMA) particles by electrostatic interaction. The surface of the PMMA-silica composite particles exhibited raspberry-like morphology with high surface roughness. Hollow silica particles were then obtained by calcination to selectively remove the PMMA core. Subsequent modification with nonafluorohexyltriethoxysilane (NFH-silane) conferred superhydrophobicity on the hollow silica particles. The surface property of this particles were investigated by measuring their water contact angle, and the results showed that such perfluorinated raspberry-like hollow particles had unique superhydrophobic.     

Fabrication of superhydrophobic copper by wet chemical reaction

A wet chemical reaction was employed herein to fabricate a stable superhydrophobic surface on a polished copper substrate at ambient temperature. The resulting surface showed superhydrophobic properties as evidenced by a water contact angle (CA) of about 154° and a water sliding angle (SA) of about 4°, which may be attributed to the combination of the roughened surface morphology by means of wet chemical reaction and the formed low surface free energy per chemical modification with poly (dimethysiloxane) vinyl terminated (PDMSVT). Scanning electron microscopy (SEM) images of the resulting surface reveal the resulted copper oxalate microscopic sizes with average diameter of about 0.5 μm and circular submicroscopic structures with diameter of about 100 nm, constructing a hierarchical structure consisted by micro- and nano-scale elements similar to that of lotus leaf in some extent. The elemental and chemical compositions of the resulting surface were also identified by Powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. This work provides improved understanding of the effect of surface roughness and surface energy on superhydrophobicity.     

Superhydrophobic carbon nanotube/polydimethylsiloxane composite coatings

This paper reports a method for fabricating carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite superhydrophobic coatings. With toluene as a solvent, the coating is obtained directly by spray of CNT/PDMS/toluene suspension. The hydrophobicity and micro-/nanostructure of the coatings are studied with respect to the mass ratio (MR) of CNT to PDMS. Based on the multiscale morphology analysis, it is shown that the nanoscale roughness is essential for achieving superhydrophobicity. To form nanoscale rough surface and obtain a stable superhydrophobic coating, MR>0·3 is recommended. In addition, such coatings also show small slide angle, low adhesion strength and long term stability of the coated surface. The method reported in this study is low cost and especially suitable for engineering applications.     

Fabrication of superhydrophobic TPU film for oil-water separation based on electrospinning route

In this work, we described an electrospinning process for creating superhydrophobic thermoplastic polyurethanes (TPU) mat with bead-on-string morphologies. The initially hydrophobic TPU electrospun film presented superhydrophobic trait after treatment with hydrophobic nanosilicas, which was pre-fabricated by refluxing nanosilicas in a toluene solution of hexadecyltrimethoxysilane (HDTMS). The relationship between the microstructures and wettability was also discussed. This superhydrophobic TPU film turned out to be benign materials for separating oil and water mixture. The development of the electrospun process described in this paper, as well as the extension of our method, will no doubt facilitate the achievement of other functional superhydrophobic films for various applications.     

玻璃纤维增强环氧复合材料上超疏水表面层的制备

先采用真空袋压法制备含CaCO3/环氧树脂表面功能层的玻璃纤维增强环氧树脂复合材料,再通过化学刻蚀与表面修饰,在玻璃纤维增强环氧树脂复合材料上制备出超疏水表面。采用扫描电镜和动/静态接触角分析仪,表征表面的形貌和疏水性,结果表明,在复合材料表面构建了具有微-纳米尺度二元粗糙结构;采用1%(质量分数)的硬脂酸修饰后,其表面与水的接触角最高达160.03°;制备的超疏水表面结构在室温环境下具有长期的稳定性。     

Multifunctional superhydrophobic coatings fabricated from basalt scales on a fluorocarbon coating base

Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceed-ingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applications in marine environments are still hindering commercial-scale deployment.This study is focused on development of easy-to-apply superhydrophobic coatings,with multifunctional capa-bilities,in order to extend the integrity and durability of the coatings in harsh marine environments.Here,a set of facile methods involving selective chemical etching using concentrated NaOH,as well as fluori-nation with perfluoropolyether methyl ester were adopted to fabricate a superhydrophobic surface on basalt scales,having the required rough hierarchical micro-nanotextured and low surface energy.The superhydrophobic basalt scales were subsequently aligned atop a fluorocarbon resin,pre-deposited on a metal substrate,to yield a multifunctional superhydrophobic coating(3 μL water droplet;contact angle=165.1°,rolling angle=0.7°),easily amenable to large surface area application and having excellent wear resistance,UV-aging resistance,salt spray resistance,corrosion resistance and antibacterial capabilities.