仿生超疏水聚丙烯薄膜的制备与性能

采用简单溶剂/非溶剂法制备出超疏水性聚丙烯薄膜。该薄膜表面与水的接触角为160°,滚动角小于4°。pH值为1～14的水溶液在其表面都有很高的接触角。通过对表面进行扫描电子显微镜分析可知,薄膜具有类鸟巢状多孔微纳米复合微观结构,这种结构可捕获空气,形成水与基底之间的气垫,对表面超疏水性的产生起到了关键的作用。用Cassi...     

海泡石超疏水复合涂层的制备和性能

在不同条件下在有机化改性的海泡石粉体悬浮液中加入表面活性剂进行偶联改性,然后进行超声、离心脱水、洗涤、干燥和研磨制得粉体,再使用无水乙醇和分散制成涂料,将涂料涂敷于载玻片表面制备出海泡石超疏水涂层.使用OCA 20接触角测试仪测试涂层与水的接触角(CA)和滚动角(SA),使用BRUKER-80v傅里叶红外光谱仪分析改性...     

新型陶瓷基复合超疏水涂层的制备及其性能

为了研究开发新型超疏水涂层的制备方法,改善涂层的结构与性能,以Al₂O₃-40%TiO₂(AT40)、PFA(全氟烷氧基乙烯基醚共聚物)粉末为原始材料,采用大气等离子喷涂(APS)技术,并调整电流、氩气流量等喷涂参数,在铝合金基体表面制备了两种不同的AT40/PFA复合超疏水涂层。利用相对应的测试仪器及分析手段对喷涂态涂层的相组成、显微结构、摩擦系数及基本性能等进行了表征分析。结果表明,两种涂层的相组成均为C₂₀F₄₂、Al₂TiO₅及少量的γ-Al₂O₃、α-Al₂O₃相;涂层表面均为圆形和椭圆形的粒状突起结构,其中突起结构的表面均存在类似荷叶表面结构的二元微纳米乳突结构,其表面粗糙度为9.3 μm和12.41 μm;所得涂层具有良好的综合性能,与水的静态接触角均达到了150°以上,滚动角为4~5°;在其他参数不变的情况下,随着电流的增大及氩气流量的减小,涂层中的陶瓷相含量增加,涂层的粗糙度、摩擦系数、显微硬度及结合强度均增大。     

仿生超疏水聚丙烯/二氧化钛复合薄膜的构筑及性能研究

采用简便的相分离法制备出超疏水PP/TiO2复合薄膜。该复合薄膜表面与水的接触角为169°,滚动角小于4°。pH值为1~14的水溶液在其表面都具有很高的接触角,均大于160°。对其表面进行扫描电子显微镜分析可知,该薄膜具有类花瓣二元微纳米复合微观结构,这种结构可捕获空气,形成水与基底之间的气垫,对表面超疏水性的产生起到了关键作用。用Cassie理论对其表面超疏水进行分析,结果表明,约2.7%的面积是水滴和基体接触,而有约97.3%的面积是水滴和空气接触。     

Superhydrophobic Behavior and Optical Properties of ZnO Film Fabricated by Hydrothermal Method

ZnO film with claviform structure was synthesized on quartz substrates through a hydrothermal method at 90℃.The microstructure of the film is composed of clusters of submicrometer rods,which therefore endues the film with good superhydrophobicity.Meanwhile,the film with such tanglesome structure also shows highly crystalline quality testified by a strong ultra-violet (UV) emission and very low deep-level emission observed on the photoluminescence (PL) spectrum as well as high transparence of about 89% transmittance in visible light range.     

Superhydrophobic Coatings on Cellulose‐Based Materials: Fabrication,Properties, and Applications

Wettability of a solid surface by a liquid plays an important role in several phenomena and applications, for example in adhesion, printing, and self‐cleaning. In particular, wetting of rough surfaces has attracted great scientific interest in recent decades. Superhydrophobic surfaces, which possess extraordinary water repelling properties due to their low surface energy and specific nanometer‐ and micrometer‐scale roughness, are of particular interest due to the great variety of potential applications ranging from self‐cleaning surfaces to microfluidic devices. In recent years, the potential of superhydrophobic cellulose‐based materials in the function of smart devices and functional clothing has been recognized, and in the past few years cellulose‐based materials have established themselves among the most frequently used substrates for superhydrophobic coatings. In this Review, over 40 different approaches to fabricate superhydrophobic coatings on cellulose‐based materials are discussed in detail. In addition to the anti‐wetting properties of the coatings, particular attention is paid to coating durability and other incorporated functionalities such as gas permeability, transparency, UV‐shielding, photoactivity, and self‐healing properties. Potential applications for the superhydrophobic cellulose‐based materials range from water‐ and stain‐repellent, self‐cleaning and breathable clothing to cheap and disposable lab‐on‐a‐chip devices made from renewable sources with reduced material consumption.     

Superhydrophobic states

It is well known that the roughness of a hydrophobic solid enhances its hydrophobicity. The contact angle of water on such flat solids is typically of the order of 100 to 120 degrees, but reaches values as high as 160 to 175 degrees if they are rough or microtextured. This result is remarkable because such behaviour cannot be generated by surface chemistry alone. Two distinct hypotheses are classically proposed to explain this effect. On one hand, roughness increases the surface area of the solid, which geometrically enhances hydrophobicity (Wenzel model). On the other hand, air can remain trapped below the drop, which also leads to a superhydrophobic behaviour, because the drop sits partially on air (Cassie model). However, it is shown here that both situations are very different from their adhesive properties, because Wenzel drops are found to be highly pinned. In addition, irreversible transitions can be induced between Cassie and Wenzel states, with a loss of the anti-adhesive properties generally associated with superhydrophobicity.     

疏水二氧化硅/聚苯乙烯超疏水复合涂层的简易制备及其防沾污性研究

采用喷枪及家用简易喷雾器在含有聚乙烯(PE)膜的纸张表面制备了含疏水二氧化硅纳米颗粒和聚苯乙烯的超疏水复合涂层。随着疏水二氧化硅纳米颗粒含量的增加,表面逐渐被二氧化硅颗粒覆盖,并且形成微纳米孔洞结构,达到超疏水性,并具有良好的耐粘附稳定性,水、牛奶和橙汁等液滴可从这些超疏水表面滚落而不残留,具有良好的防沾污能力。     

Superhydrophobic Graphene Foams

The static and dynamic wetting properties of a 3D graphene foam network are reported. The foam is synthesized using template‐directed chemical vapor deposition and contains pores several hundred micrometers in dimension while the walls of the foam comprise few‐layer graphene sheets that are coated with Teflon. Water contact angle measurements reveal that the foam is superhydrophobic with an advancing contact angle of ～163 degrees while the receding contact angle is ～143 degrees. The extremely water repellent nature of the foam is also confirmed when impacting water droplets are able to completely rebound from the surface. Such superhydrophobic graphene foams show potential in a variety of applications ranging from anti‐sticking and self‐cleaning to anti‐corrosion and low‐friction coatings.     

Influence of Heterogeneous Magnetism on Magneto-Optical Properties

The influence of inhomogeneity on magnetic materials is considered; in particular, we examine how it affects the magneto-optical (MO) response of films and multilayers. From ab initio calculations of the band structure, the optical conductivity tensor is derived, providing the basis for computing the MO spectra. The presence of magnetic nanoprecipitates is taken into account by modeling the system as an effective medium or as an infinitely thin layered structure. A possible depth concentration distribution of the magnetic species is also accounted for, by considering the structure as a sequence of layers. This formalism is applied to some real systems constituted by magnetic particles dispersed in a hosting nonmagnetic matrix. The agreement between theoretical and measured MO Kerr effect spectra supports the validity of the model and establishes its predictive power, suggesting that the analysis of experimental MO spectra can provide information not only on the magnetic, but also on the structural properties of heterogeneous magnetic systems.     

超疏水表面抗结冰性能研究进展

阐述了近期国内外对超疏水表面抗结冰的研究进展,以期弄清这种特殊浸润性表面的抗结冰性能。发现必须根据超疏水表面的微结构类型判断其能否抗结冰,而不能只依据接触角进行笼统的判断。有些超疏水表面,其抗结冰能力随着结冰-融冰循环次数的增加而下降。在低温高湿条件下,很多超疏水表面的抗结冰能力会因水蒸气在表面微纳结构的间隙内冷凝而恶化.因此,设计机械强度高的超疏水表面(耐结冰融冰循环)、或能使冷凝水滴在其上自迁移的新型超疏水表面、或者简单地在固体表面沉积一层光滑牢固的疏冰涂层,或许是制备持久抗结冰表面的现实、可靠选择。     

Experimental Study on Deicing Performance of Carbon Fiber Reinforced Conductive Concrete

Carbon fiber reinforced concrete (CFRC) is a kind of good electrothermal material. When connected to an external power supply, stable and uniform heat suitable for deicing application is generated in the CFRC slab. Electric heating and deicing experiments of carbon fiber reinforced concrete slab were carried out in laboratory, and the effect of the temperature and thickness of ice, the thermal conductivity of CFRC, and power output on deicing performance and energy consumption were investigated. The experimental results indicate that it is an effective method to utilize the thermal energy produced by CFRC slab to deice. The time to melt the ice completely decreases with increasing power output and ice temperature, and increases with increasing thickness of the ice. The energy consumption to melt 2 mm thickness of ice varies approximately linearly from 0.556 to 0.846 kW·h/m2 as the initial temperature ranges from -3℃ to - 18℃. CFRC with good thermal conduction can reduce temperature difference in CFRC     

Superhydrophobic functionalized graphene aerogels

Carbon-based nanomaterials such as carbon nanotubes and graphene are excellent candidates for superhydrophobic surfaces because of their intrinsically high surface area and nonpolar carbon structure. This paper demonstrates that graphene aerogels with a silane surface modification can provide superhydrophobicity. Graphene aerogels of various concentrations were synthesized and the receding contact angle of a water droplet was measured. It is shown that graphene aerogels are hydrophobic and become superhydrophobic following the application of a fluorinated surfactant. The aerogels produced for this experiment outperform previous carbon nanomaterials in creating superhydrophobic surfaces and offer a more scalable synthetic procedure for production.     

Influence of Through-Thickness Pinning on Composite Shear Properties

This paper describes results from tests to examine the influence of through-thickness pinning on in-plane shear behaviour, measured by tensile loading of ±45° specimens. Samples were produced by both aeronautical and marine manufacturing processes. As few previous studies have investigated pinning of marine composites these were also subjected to out-of-plane shear delamination tests. For both carbon/epoxy laminates the pins reduce the apparent in-plane shear modulus and strength. Pins modify the strain field measured by full-field image analysis, and slow damage development. A new damage mechanism, transverse pin cracking, was observed.     

超疏水表面的润湿性及其应用研究

润湿性是衡量超疏水表面疏水强弱的最重要特征之一,主要由表面化学组成和表面微观结构共同决定.简述了超疏水表面的润湿性理论,综述了超疏水表面的最新研究进展,包括制备方法、应用研究及理论分析,详细介绍了其在自清洁和减阻方面的应用,最后提出了现阶段超疏水表面研究所面临的问题,并展望了其诸多领域的发展前景.