基于软印刷技术的竹材表面仿制荷叶超疏水结构

 利用软印刷技术,研究了在竹材表面仿制荷叶表面的超疏水性微纳结构。以新鲜荷叶为模板,以聚二甲基硅氧烷（PDMS）为印章,经过两次复形处理使竹材表面获得类似荷叶表面的超疏水结构。扫描电子显微镜（SEM）观测及接触角测试结果表明,制备的仿生荷叶竹材样品具有与荷叶类似的微纳乳突结构粗糙表面,其与水滴的接触角达到150.5°（平均值）,非常接近荷叶表面的接触角（154.5°）,表现出超疏水特性。仿生荷叶微纳结构竹材样品的成功制备,证实了纳米技术赋予竹材等亲水材料以超疏水性能的可行性。     

仿生超疏水导电竹材的制备及其耐久性

 采用银镜反应及分子自组装技术,在竹材表面原位负载一层纯单质银纳米粒子,赋予竹材导电功能,再经十七氟癸基三甲氧基硅烷（FAS-17）的进一步处理,制备出具有导电功能的仿生超疏水竹材试样,并通过实验观察研究了其稳定性及耐久性。结果表明,制备竹材表面拥有亚微米/纳米二维等级粗糙结构,该结构协同低表面能物质FAS-17共同决定了竹材的超疏水性,竹材表面与水的接触角为155°,滚动角小于10°;制备竹材能够抵抗pH 1~14溶液及强浓度NaCl溶液,且经强烈的溶液搅拌及蒸煮,依旧保持超疏水性和导电性。     

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.     

八宝景天叶片表面润湿性测试与疏水机理分析

为探寻用于超疏水表面制备的仿生原型,测试了八宝景天(Hylotelephium erythrostictum)叶片表面对水滴的润湿性,采用扫描电镜和三维形貌干涉仪对叶片表面微形貌结构进行观测并提取特征参数,基于Wenzel方程和Cassie-Baxter方程构建模型用以分析叶片表面的疏水机理。结果表明:润湿性随叶片类型的不同而呈现差异,其中新鲜幼叶正、反表面的接触角分别为(147.25±3.79)°和(137.46±4.03)°,新鲜幼叶反面的接触角高达152.54°;叶片表面由排列连续致密且呈椭球形的凸包和交错排列成网状且形貌不规则但可辨别轮廓的蜡质晶体构成,不同类型叶片表面的凸包形貌呈现显著差异但蜡质晶体形貌未有明显区别;幼叶正、反表面的凸包具有相似的高度但分布密度和投影面积显著不同,蜡质晶体层的高度和面积比未有明显差异;微米级凸包和纳米级蜡质晶体的协同作用使叶片表面呈现疏水特性且蜡质晶体发挥关键作用。基于Cassie-Baxter方程构建的模型能够有效揭示叶片表面的疏水机理,并可为超疏水表面的仿生制备提供理论支持。     

Chemically robust carbon nanotube – PTFE superhydrophobic thin films with enhanced ability of wear resistance

A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene(PTFE) and carbon nanotubes.The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer.Thin films with a contact angle of 154.1°± 2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm~2.The thin film is also extremely stable even under much stress conditions.To further the understanding of the enhancement of wear resistance,we investigated the formation of microsized structure and their effects.The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.     

工业化超疏水TiO2涂层的简易制备和性能研究

为探究适合工业化生产用超疏水纳米TiO₂的绿色改性工艺,以饱和脂肪酸A、硅烷B、纳米TiO₂（P25）等为原料制备超疏水TiO₂粉末,与环氧树脂混合后利用喷涂法制备出超疏水涂层。采用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱仪和接触角分析仪对超疏水粉末和超疏水涂层表面的形貌和疏水性进行了表征。结果表明：超疏水TiO₂粒子表面具有疏水性基团和微-纳米双重粗糙结构,粒子表面的静态水接触角为158°,滚动角为3°;当超疏水TiO₂与环氧树脂的质量比在3.2～3.5时,超疏水涂层既保持超疏水性,又与基底稳固结合,同时具有自清洁性和可修复性。该工艺操作简单方便,成本低,疏水性好,无需特殊设备,工艺环保,适应工业化生产,可用来大面积制备超疏水涂层,拥有较高的商业价值。     

超疏水表面仿生原型制备技术研究分析

超疏水表面(superhydrophobic surface)是指水滴静态接触角>150°且滚动角<10°的材料表面,广泛应用于自清洁、防腐蚀、疏水抑冰与船舰减阻等诸多工程领域。基于仿生工程学原理,人们对典型超疏水仿生原型进行广泛研究,以期获取超疏水表面研制的理论基础。从呈现超疏水润湿现象的典型动植物体表入手,综述其表面微形貌结构特征对超疏水润湿特性的影响机制,介绍材料表面超疏水润湿行为量化表征的数学模型;重点关注仿生超疏水表面制备技术的最新研究进展,包括传统制备方法与3D打印制备技术,以及超疏水表面制备样件的功效表征;分析指出仿生超疏水表面的低成本、大面积、功效持久性是该领域未来发展的重要方向。研究成果可加深学者对超疏水润湿特性的认知,推动超疏水表面仿生研制新思路、新方法、新技术的发展。     

锌基底上含金属锡的超疏水表面的制备

针对超疏水金属表面广阔的应用前景,采用氯化亚锡的丙酮溶液,十八硫醇的丙酮溶液为疏水剂在锌基底上构建了超疏水表面,通过X-射线衍射(XRD)和扫描电镜(SEM)进行了结构表征和疏水性能测试.结果表明,超疏水表面具有微纳米阶层结构,静态接触角为158°,滚动角小于5°.     

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.     

B10白铜表面超疏水膜的制备及其耐腐蚀性能研究

以B10白铜为基底,采用刻蚀、煅烧和表面改性的方法制备了超疏水膜,采用K100-MK2型张力仪测量超疏水膜的接触角,采用扫描电子显微镜观察超疏水膜的表面形貌,采用电化学工作站测试超疏水膜在3.5% NaCl（%表示质量分数）水溶液中的耐腐蚀性能。结果表明,刻蚀、煅烧后的B10白铜样品分别在溶液A中改性5 min、在溶液B中改性12 h后,得到的两种超疏水膜的接触角可分别达到153.2°和151.5°。将两种超疏水膜分别在3.5% NaCl水溶液中腐蚀10 d后,与裸B10白铜相比,仍表现出较好的耐腐蚀持久性。该方法为制备具有抗腐蚀和自清洁性能的超疏水表面提供了一条有效途径,可用于金属材料的表面改性。     

Biomimetic fabrication and characterization of an artificial rice leaf surface with anisotropic wetting

In nature,rice leaves exhibit special anisotropic sliding capabilities.Although researchers have succeeded in fabricating artificial rice leaf structures and realizing the wettability function of the leaf surface,these methods used to date are complex and do not allow the fabrication of surfaces with large area.Herein,we adopted a simple technology—two steps soft transfer to fabricate biomimetic rice leaf.The fabricated surface well reproduced the structures of the rice leaf surface and exhibited a static superhydrophobic property similar to that of the real rice leaf surface.In terms of its dynamic wettability,it clearly exhibited an anisotropic sliding property.Systematic measurements showed that the sliding angles parallel and perpendicular with the vein direction were 25° and 40°,respectively.The method was simple and reliable,without the need for expensive instruments and complex technologies,which could be used for the rapid fabrication of large-area artificial rice leaf surfaces.We believe that the artificial rice leaf surface fabricated by this method has great potential applications in biomimetic functional surfaces,microfluidics,and so on.     

微波等离子体处理对竹材表面接触角的影响

采用微波等离子体(MWP)对竹材进行了表面处理,测定了处理前后甘油和脲醛树脂胶在其表面的接触角,以此评价竹材表面改性的效果.结果表明:随MWP处理时间延长和试件距反应腔距离减小,竹材表面接触角呈降低趋势;竹材试件距反应腔距离40mm时,用甘油作测试液体在接触15 s时测试,MWP处理30 s即可将竹材表面接触角降低49%～59%;甘油所测竹材表面接触角较脲醛树脂胶所测值低,测试液滴到样品上15 s所测竹材表面接触角较5 s时低;在经等离子体处理后,砂光与否对竹材的表面性能影响不大,砂光后再经等离子体处理,比直接进行等离子体所得到的改性效果稍好.     

Effect of upper contact line on sliding behavior of water droplet on superhydrophobic surface

With a low surface energy, high apparent contact angle(>150°) and low sliding angle(<5°), superhy- drophobic surface has recently been attracting a great deal of attention. The true factor determining the sliding angle still remains unclear. In this paper, various superhydrophobic silicon surfaces with pillars are fabricated by photolithography and hydrophobized with octadecyltrichlorosilane (OTS). Relations between sliding angles and micro-structured surfaces are being investigated in detail with 10 mg wat...     

Sprayable coating based on fluorinated silica nanocomposites with superhydrophobic and antibacterial properties for advanced concrete

The porous hydrophilic nature of concrete structures makes them highly susceptible to chemical attack and bacterial adhesion, and the durability of concrete structures gradually decreases. In this work, a kind of sprayable coating with superhydrophobic and antibacterial properties was developed, which was used for surface engineering of concrete via the hydrophilic property of concrete and capillary action. The treated surface of concrete exhibited significant superhydrophobicity, with a static water contact angle of 162.4° and a sliding angle of 5°. The water absorption values of the treated concrete samples in merged in deionized water and 3.5 ?wt% NaCl solution for 7 days were measured as 1.85% and 2.71%, indicating the enhancement of water repellency by 72.03% and 80.11%, respectively. The antibacterial characterization revealed that the superhydrophobic coating enabled significantly reduced adhesion of bacteria, with the antibacterial rates of 84.57 ?± ?2.5% for E. coli and 90.43 ?± ?1.6% for S. epidermidis, respectively. The superhydrophobic coating provides hydrophobic protection for porous substrate structures and effectively reduce the corrosion damage of substrate materials, which is of practical significance for improving the durability of concrete structures.     

一步法合成耐久性水基超疏水TiO2/DTMS涂层

为制备具有优异自清洁功能的耐久性水基超疏水涂层，以十二烷基三甲氧基硅烷(n-dodecyltrimethoxysilane, DTMS)为有机改性物，通过一步法在纳米TiO₂表面嫁接长链烷基官能团得到超疏水TiO₂/DTMS涂层。分析了TiO₂涂层及TiO₂/DTMS涂层的表面润湿性、形貌和化学组成，并对所得超疏水TiO₂/DTMS涂层的自清洁性能、机械及化学稳定性进行了测试。结果表明：超疏水TiO₂/DTMS涂层表面水接触角(water contact angle, WCA)达到159°；以亚甲基蓝粉末作模拟污染物，涂覆有超疏水TiO₂/DTMS涂层的玻璃具有优异的自清洁性能；经机械磨损(10 min)、酸碱液(pH=1、3、5、7、9、11、13)浸泡、高低温(−20、30、60、90、120、150 ℃)处理后超疏水TiO₂/DTMS涂层的WCA仍大于150°，表明其具有优异的机械和化学稳定性，可用于室外防污，如建筑物外墙、玻璃、太阳能电池板等。     

二氧化硅／有机蒙脱土复合超疏水涂层的制备及其性能研究

将全氟辛基三乙氧基硅烷（FAs）改性的二氧化硅颗粒与有机蒙脱土（OMMT）混合制成溶胶,采用浸渍提拉法制备具备超疏水性能的复合涂层,研究了二氧化硅／OMMT不同配比对涂层疏水性能的影响。结果表明,复合涂层的静态接触角随二氧化硅／OMMT质量比的增加而增大,滚动角随二氧化硅／OMMT质量比的增加而减小。通过扫描电子显微镜（SEM）观察涂层表面微观结构,发现超疏水涂层表面具有微纳米复合结构,结合FAS改性二氧化硅的低表面能,赋予了复合涂层优良的超疏水性能。     

超疏水磁性纤维素粒子的制备及性能表征

 采用纤维素为原料,制备了超疏水磁性纤维素粒子。竹溶解浆用氢氧化钠/尿素/水体系溶解,在水中再生形成纤维素粒子。再采用原位沉淀法制得磁性纤维素粒子,正十八烷基三甲基硅烷修饰后得到超疏水磁性纤维素粒子。用扫描电镜（SEM）、傅里叶红外光谱仪（FT-IR）、热失重分析仪（TG）和液滴形状分析仪（CA）对改性纤维素粒子的形貌、化学结构、热稳定性和超疏水性进行了分析。改性纤维素粒子表现出超疏水性能和磁响应性能,水接触角达到151.2°。改性纤维素粒子可以包裹水滴和甘油形成液体弹珠。     

表面活性剂与PTFE涂层结构对润湿性的影响

以粗糙的超疏水聚四氟乙烯(PTFE)涂层为基体,研究表面活性剂的加入对溶液在粗糙PTFE涂层表面润湿性的影响.利用粗糙PTFE涂层表面Cassie方程计算和原子力显微镜(AFM)对表面活性剂分子在涂层表面的形貌进行表征.结果表明,在低表面张力范围内表面活性剂溶液不能润湿粗糙的超疏水PTFE涂层,而具有相似表面张力的有机溶剂可以润湿涂层表面.表面活性剂溶液与粗糙PTFE涂层表面接触时的空气分率始终维持在0.5以上,溶液不能完全进入PTFE粗糙结构,这点是导致低表面张力的表面活性剂溶液在粗糙PTFE涂层上不能润湿的原因.     

Simple nanofabrication of a superhydrophobic and transparent biomimetic surface

This paper describes a simple fabrication method for creating superhydrophobic and transparent glass surfaces that mimic natural surfaces such as lotus leaves, moth eyes or cicada wings. Nanostructured glass surfaces were created by a combination of colloidal lithography and plasma etching. A colloidal mask was formed simply by the spin coating of the polystyrene beads and with modification of the interparticle distance between the beads. The etching of the glasses was conducted by CF4 plasma. Tower-shaped nanostructures at an aspect ratio of 1：4 were treated using fluoroalkylsilane selfassembled monolayers （SAMs） to obtain the hydrophobic surfaces. The treated glass surfaces showed superhydrophobicity with a water contact angle of around 150° and a hexadecane contact angle of around 110° Furthermore, the nanostructured glass was transparent to visible light.     

毛竹竹秆直径与材积的垂直格局

将毛竹(Phyllostachys edulis)竹秆等长分割成40段,分别测量各竹段底边周长、壁厚、节隔厚,研究毛竹竹秆直径与材积的垂直格局,并构建毛竹竹秆直径相对值、相对外围累计材积、相对实际累计材积和相对节隔累计材积与竹秆相对高度的回归模型、毛竹外围材积、实际材积和节隔材积与胸径的回归模型等共7个模型.结果表明:不同胸径的毛竹竹秆直径相对值、各相对累计材积随着相对高度的增加,变化规律表现出显著的一致性,反映了毛竹竹秆结构方面的共性.