CaCO3/SiO2复合粒子涂层的表面结构及其疏水性能研究

以机械高速搅拌法制备了具有草莓结构的CaCO₃/SiO₂复合粒子,并对其进行了表面修饰改性.利用聚硅氧烷的自组装功能,将制备的复合粒子与硅氧烷一起制备了具有“荷叶效应”的超疏水涂层,静态水接触角达169°,滚动角约为2°.通过扫描电镜观察涂层的表面微观形貌,发现该涂层具有微米-纳米相结合的双层粗糙结构.微米凸起的粒径在2～3μm左右,纳米凸起的粒径约为200nm左右,与荷叶具有类似的结构排布方式.通过原子力显微镜和接触角的测试,探讨了表面微观结构、涂层粗糙度和涂层疏水性能之间的关系.结果表明：复合粒子构成的非均相界面的水接触角符合Cassie模型.复合粒子赋予涂层的双微观粗糙结构与自组装成膜硅氧烷的低表面能的协同效应,使涂层具有了优良的超疏水性能.     

非晶型超疏水和超亲水TiO2薄膜的制备与表征

通过溶胶-凝胶法, 以载玻片为基底制得非晶型纳米TiO₂薄膜, 用SEM、 XPS、 XRD和接触角测量仪研究了薄膜的微观形貌、 表面元素、 晶型结构及薄膜的疏水性, 用Wenzel、 Cassie 理论对纳米TiO₂薄膜的润湿性进行了理论分析。结果表明, 经紫外光照射16 h后, 薄膜表面由超疏水性变为超亲水性, 接触角接近0°。薄膜表面合适的粗糙度和低表面能材料表面修饰的协同作用使其表现出良好的超疏水性。     

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 sticky and slippery superhydrophobic surfaces via spin-coating silica nanoparticles onto flat/patterned substrates

Silica nanoparticles were spin-coated onto a flat/patterned (regular pillar-like) substrate to enhance the surface roughness. The surface was further modified by a self-assembled fluorosilanated monolayer. The advancing/receding contact angle and sliding angle measurements were performed to determine the wetting behavior of a water droplet on the surface. It is interesting to find that a transition from a Wenzel surface to a sticky superhydrophobic surface is observed due to the spin-coating silica nanoparticles. A slippery superhydrophobic surface can be further obtained after secondary spin-coating with silica nanoparticles to generate a multi-scale roughness structure. The prepared superhydrophobic substrates should be robust for practical applications. The adhesion between the substrate and nanoparticles is also examined and discussed.     

碱式硫酸镁晶须复合SiO2纳米粒子制备高/低黏附性超疏水涂层

超疏水材料因性能独特,应用前景广阔而被广泛关注。本文采用碱式硫酸镁晶须(MOSWs)与二氧化硅纳米粒子制备超疏水涂层,首先对MOSWs及50 nm、500 nm SiO₂进行表面改性以降低表面能,然后基于混料实验将三者按比例混合以构造表面粗糙度,以接触角、滚动角及平均粗糙度R_a为响应变量建立回归模型,分析了混合分量的形貌、尺寸与混合比例对响应变量的影响,并探讨了超疏水涂层微观结构对水滴黏附性的影响以及粗糙度与超疏水性能之间的关系。结果表明：MOSWs复合SiO₂纳米粒子可制备具有不同黏附性的超疏水涂层,单独使用MOSWs可制备高黏附性超疏水涂层,其接触角达152.59°,涂层水平倒置水滴不滴落;而MOSWs与50 nm SiO₂以相同质量分数混合,可制备低黏附性超疏水涂层,其接触角达163.25°,滚动角可趋近0°。所制备涂层的平均粗糙度R_a值位于5～10μm之间时,接触角较大,滚动角较小,超疏水性能较佳。     

环保超疏水防潮瓦楞纸箱的制备及性能研究

目的 针对瓦楞纸箱易受潮而使其失去原有性能的问题,对其进行超疏水防潮改性,并研究改性方法对其性能的影响。方法 通过真空吸附涂布的方式,采用具有低表面能的硬脂酸与可构建表面粗糙度的纳米二氧化硅粒子结合,再引入聚二甲基硅氧烷增强涂层与纸板之间粘合力的方法制备超疏水防潮纸箱,对其进行润湿性和力学性能的表征。结果 改性后的纸板水接触角可达到150°以上,水分吸附率大幅降低,在此基础之上其边压强度未受到不良影响,且耐磨性能优良。结论 文中所述超疏水涂层的制备工艺简单,材料绿色环保,所得纸箱防潮性能、力学性能良好。     

仿生超疏水棉织物的制备与表面分析

以荷叶表面微/纳米结构为参考模型,先用硅溶胶处理天然棉织物,再用N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO-1)对其进行修饰,获得了微/纳米二元粗糙的超疏水织物,水滴在该织物表面接触角可达160.5°。场发射扫描电子显微镜(FE-SEM)观察发现超疏水纤维表面存在大量均匀分布的纳米微凸体。接触角分析表明织物织造过程中形成的微米级粗糙度和ASO-1膜的存在是织物疏水的主要原因,纳米微凸体能减少纤维与水的接触面积,提高水在纤维表面的接触角,使织物由疏水转变为超疏水。最后用X射线光电子能谱仪(XPS)证实了纤维表面SiO2粒子和ASO-1膜的存在。     

Hierarchically structured superhydrophobic coatings fabricated by successive Langmuir-Blodgett deposition of micro-/nano-sized particles and surface silanization

The present study demonstrates the creation of a stable, superhydrophobic surface by coupling of successive Langmuir-Blodgett (LB) depositions of micro-?and nano-sized (1.5?μm/50?nm, 1.0?μm/50?nm, and 0.5?μm/50?nm) silica particles on a glass substrate with the formation of a self-assembled monolayer of dodecyltrichlorosilane on the surface of the particulate film. Particulate films, in which one layer of 50?nm particles was deposited over one to five sublayers of larger micro-sized particles, with hierarchical surface roughness and superhydrophobicity, were successfully fabricated. Furthermore, the present 'two-scale' (micro-?and nano-sized particles) approach is superior to the previous 'one-scale' (micro-sized particles) approach in that both higher advancing contact angle and lower contact angle hysteresis can be realized. Experimental results revealed that the superhydrophobicity exhibited by as-fabricated particulate films with different sublayer particle diameters increases in the order of 0.5?μm>1.0?μm>1.5?μm. However, no clear trend between sublayer number and surface superhydrophobicity could be discerned. An explanation of superhydrophobicity based on the surface roughness introduced by two-scale particles is also proposed.     

Superhydrophobic surfaces on cotton textiles by complex coating of silica nanoparticles and hydrophobization

By the complex coating of amino- and epoxy-functionalized silica nanoparticles on epoxy-functionalized cotton textiles to generate a dual-size surface roughness, followed by hydrophobization with stearic acid, 1H,1H,2H,2H-perfluorodecyltrichlorosilane, or their combination, superhydrophobic surfaces were prepared. The static water contact angle of the most superhydrophobic sample as prepared reaches 170° for a 5 μL droplet. The wettability and morphology were investigated by contact angle measurement and scanning electron microscopy. Characterizations by Fourier transformation infrared spectroscopy, and thermal gravimetric analysis were also conducted.     

Hierarchical Structured Multifunctional Self‐Cleaning Material with Durable Superhydrophobicity and Photocatalytic Functionalities

Self‐cleaning materials, which are inspired and derived from natural phenomena, have gained significant scientific and commercial interest in the past decades as they are energy‐ and labor‐saving and environmentally friendly. Several technologies are developed to obtain self‐cleaning materials. The combination of superhydrophobic and photocatalytic properties enables the efficient removal of solid particles and organic contaminations, which could reduce or damage the superhydrophobicity. However, the fragility of the nanoscale roughness of the superhydrophobic surface limits its practical application. Here, a hierarchical structure approach combining micro‐ and nanoscale architectures is created to protect the nanoscale surface roughness from mechanical damage. Glass beads of 75 µm are partially embedded into a low‐density polyethylene film. This composite surface is coated with silicone nanofilaments (SNFs) via the droplet‐assisted growth and shaping approach, providing the nanoscale surface roughness as well as the support for the photocatalyst with enlarged surface area. TiO₂ nanoparticles, which serve as the photocatalyst, are synthesized in situ on SNFs through a hydrothermal reaction. The self‐cleaning effect is proved using wettability measurements for various liquids, degradation of organic contamination under UV light, and antibacterial tests. The enhanced mechanical durability of the hierarchical structure of the composite material is verified with an abrasion test.     

2A12铝合金基体超疏水表面制备及性能研究

铝合金在使用过程中极易引发基体腐蚀现象,如点蚀、晶间腐蚀等,为保障铝合金在腐蚀环境中的应用,可通过建立超疏水表面改变铝合金表面的润湿性,从而在一定程度上减少腐蚀液与铝合金表面的接触,进而改善耐蚀性。本文通过酸刻蚀和沸水刻蚀两种方法在铝合金表面构筑微纳米结构,并使用低表面能物质硬脂酸进行表面处理得到超疏水表面。采用扫描电子显微镜、接触角测试仪、原子力显微镜分别对铝合金表面形貌、疏水性和粗糙度进行测试,得到两种方法的最佳制备时间,而后通过极化曲线对两种方法制备的铝合金表面耐蚀性能进行对比,进而研究两种刻蚀方法对铝合金耐蚀性的影响。实验结果表明：酸刻蚀时间为15 s时,铝合金表面接触角达到峰值163.9°,呈现超疏水状态,相对于空白样品,表面粗糙度增加了24倍,电化学自腐蚀电位正向移动0.362 8 V;沸水刻蚀时间为1 min时,其表面接触角达到峰值109.6°,比空白样品疏水性强但未呈现超疏水状态,相对于空白样品,经沸水刻蚀的铝合金表面粗糙度增加了4.4倍,电化学自腐蚀电位正向移动0.074 8 V。两种方法处理得到的铝合金表面的耐蚀性与空白铝合金试样相比均有显著提高,而酸刻蚀法的缓蚀效...     

具有不同黏附力Al-Mg-Si合金超疏水表面的制备与表征

基于位错刻蚀理论利用溶液浸泡处理A1-Mg-Si合金在其表面形成微观粗糙表面结构,采用自组装技术在此表面制备FDTS自组装分子膜.采用X射线衍射仪、扫描电子显微镜和表面粗糙度仪对试样表面形貌进行了表征;采用接触角测量仪对试样表面接触角进行了测量.结果表明,试样经溶液浸泡处理和沉积自组装分子膜后,其表面润湿性实现了由亲水到超亲水再到超疏水的转变;改变溶液浸泡时间得到具有不同微观结构的表面,沉积自组装分子膜后得到的超疏水表面具有不同的滚动接触角,其表面黏附力具有明显差异.分析认为,超疏水表面的获得是溶液浸泡处理得到的粗糙表面结构和低表面能物质FDTS自组装分子膜共同作用的结果;表面黏附力的差异是试样表面微观形貌的不同造成水滴在其表面所处状态的差异引发的.     

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。     

透明超疏水聚乙烯薄膜的制备及性能分析

目的研究包装透明超疏水聚乙烯(PE)薄膜的制备方法及其性能。方法以纳米二氧化硅和无水乙醇为原料,将纳米二氧化硅溶于无水乙醇制得二氧化硅半透明溶液,采用浸渍提拉法将PE膜在二氧化硅溶液中浸泡数分钟后提拉取出并自然干燥,然后用扫描电子显微镜、接触角测量仪、透光率雾度测定仪测量膜表面的性能,并进行研究分析,用污水浸泡样品数天后测量其抗污性。结果成功制备了透明超疏水PE薄膜,其表面与水的接触角高达(171±2)°,滚动角低至1°。当纳米二氧化硅的质量浓度为10 mg/mL时,其薄膜表面表现出了优异的透明性、防水性和抗污染自清洁性。结论采用简易方法制备了透明超疏水聚乙烯塑料薄膜,提高了聚乙烯膜超疏水自清洁的性能,大大增强了聚乙烯膜在包装领域的应用前景。     

Fabrication of ZnO submicrorod films with water repellency by surface etching and hydrophobic modification

Superhydrophobic ZnO submicrorod films have been fabricated on zinc sheets through an H₂O₂-assisted surface etching process and subsequent surface modification with a monolayer of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FDS). The crystal structure, chemical compositions, morphologies, and wettability of the resultant ZnO films were analyzed by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurements. It is found that the surface of the as-prepared ZnO films on zinc substrate was hydrophobic with a water contact angle of 95 ± 2°, whereas after modification with FDS, the film exhibited superhydrophobicity and the water CA increased to 154 ± 2°. It is shown that both the higher surface roughness and the lower surface free energy play an important role in creating the superhydrophobic films.     

Superhydrophobic transparent films from silica powder: Comparison of fabrication methods

The lotus leaf is known for its self-clean, superhydrophobic surface, which displays a hierarchical structure covered with a thin wax-like material. In this study, three fabrication techniques, using silicon dioxide particles to create surface roughness followed by a surface modification with a film of polydimethylsiloxane, were applied on a transparent glass substrate. The fabrication techniques differed mainly on the deposition of silicon dioxide particles, which included organic, inorganic, and physical methods. Each technique was used to coat three samples of varying particle load. The surface of each sample was evaluated with contact angle goniometer and optical spectrometer. Results confirmed the inverse relationships between contact angle and optical transmissivity independent of fabrication techniques. Microstructural morphologies also suggested the advantage of physical deposition over chemical methods. In summary, the direct sintering method proved outstanding for its contact angle vs transmissivity efficiency, and capable of generating a contact angle as high as 174°.     

A non-fluorinated mechanochemically robust volumetric superhydrophobic nanocomposite

The widespread use of water-repellent superhydrophobic surfaces is limited by the inherent fragility of their micro-and nanoscale roughness, which is prone to damage and degradation. Here, we report a non-fluorinated volumetric superhydrophobic nanocomposites that demonstrate mechanochemical robustness. The nanocomposites are produced through the addition of microscale diatomaceous earth and nanoscale fumed silica particles to high-temperature vulcanized silicone rubber. The water-repellency of the surface and bulk of nanocomposites having 120 phr of filler was determined based on the water contact angle and contact angle hysteresis. We compared the water-repellency of nanocomposites of differing diatomaceous earth to fumed silica mass ratios. Increasing the amount of diatomaceous earth enhanced the water-repellency of the nanocomposite surface, whereas an increased amount of fumed silica improved the water-repellency of the bulk material. Moreover, increasing the diatomaceous earth/fumed silica mass ratio improved the cross-linking density and hardness values of the nanocomposite.Despite being subjected to a range of mechanical durability tests, including sandpaper abrasion,knife scratching, tape peeling, water jet impact, and sandblasting, the nanocomposite maintained a water contact angle of 163. and contact angle hysteresis of 2°. When the water-repellency of the prepared nanocomposites eventually deteriorated, we restored their superhydrophobicity by removing the upper surface of the nanocomposite. This extraordinary robustness stems from the embedded low surface energy micro/nanostructures distributed throughout the nanocomposite. We also demonstrated the chemical stability, UV resistance, and self-cleaning abilities of the nanocomposite to illustrate the potential for real-life applications of this material.     

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...     

氧化还原法制备超疏水表面及其防覆冰性能

使用化学氧化还原法制备出疏水性能优异的超疏水表面,使用接触角测量仪、扫描电镜对表面浸润性及形貌进行表征分析。制得的铝基体超疏水表面接触角高达163.31°,滚动角小于5°。探究不同反应时间对表面形貌和浸润性的影响,使用自制的结冰监测系统对制备出的超疏水表面的静态和动态水滴防覆冰性能进行探究,并结合一维传热理论和经典成核理论对实验结果进行分析。结果表明,反应80min时表面疏水效果最好,超疏水表面静态水滴延缓结冰时间约是普通样品的5倍,结冰温度也低了3.3℃,动态水滴撞击表面时,超疏水表面始终无积水和覆冰,表现出优异的静态和动态防覆冰性能。     

超疏水SiO2/PS 薄膜于木材表面的构建

通过溶胶-凝胶法一步合成疏水性且具备独特形貌的二氧化硅粒子,联合聚苯乙烯以滴涂的方式于木材表面仿生合成了稳定性超疏水薄膜。经处理后的木材表面与水的静态接触角为153°,滚动角小于5°。通过扫描电子显微镜照片观察到该复合涂层拥有微米/亚微米的二维等级粗糙结构,该结构协同低表面能物质共同决定超疏水性木材的成功制得。此外,进一步研究了超疏水性木材表面的稳定性和耐久性。结果表明,该超疏水性木材于水、腐蚀性液体(酸液/碱液)、常见有机溶剂中以及一些常见条件下仍保留超疏水特性,为未来木材材料的应用领域扩展提供了有利条件。