Name: fabrication of superhydrophobic metal surfaces for anti-icing applications
Uploaded: 2018-08-15T13:30:00.000+00:00
Duration: 11 min 20 s
Description: Watch this Scientific Journal Video about Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications at JoVE.com

这项研究得到了项目的支持: MAT2014-60615-R 和 MAT2017-82182-R 由国家研究局和欧洲区域发展基金 (ERDF) 资助。

注意: 该协议遵循图 2所示的方案。
1. 样品准备
<ol><li>
切割和清洗
	<ol>
<li>使用金属剪切, 切割250毫米 x 250 毫米 x 0.5 毫米铝板成25毫米 x 45 毫米 x 0.5 毫米件。 注: 使用金属剪切时必须特别小心, 必要时需特别训练。</li>
		<li>卸下覆盖样品一侧的保护膜, 用大约50毫升的清洗液清洗这一边。用戴手套的手轻轻地冲洗样品。避免使用磨料擦洗器。</li>
		<li>在蒸馏水的流动中大量冲洗样品。随后, 将每个样品浸泡在30毫升的96% 乙醇中, 将其油脂实验为 300s, 并在30毫升的超纯水中重复300s。</li>
		<li>将样品从水中取出, 在室温下晾干1小时。</li>
	</ol>
</li>
	<li>
酸性蚀刻
	<ol>
<li>对于蚀刻反应, 在超纯水中制备 4 M 溶液 HCl13。将每个样品浸入这个溶液中的80毫升480s。当本机氧化物表面层被去除, 反应在大约360s 以后变得更加剧烈。 注意: 为了安全起见, 在遮光罩中进行这种反应。戴手套、实验室大衣和防护眼镜。</li>
		<li>在装有酸溶液的烧杯旁边, 用超纯水准备另一个烧杯, 突然停止反应。使用聚四氟乙烯镊子, 从酸溶液中取出样品并浸入水中。在丰富的超纯水中冲洗样品。</li>
		<li>通过过滤和压缩空气吹干样品。请注意, 蚀刻反应后的样品干火干燥可能是一项艰巨的任务。在水的宏观去除以后吹, 去除水的踪影在烤箱在120°c 为600s。 注意: 这个干燥过程中必不可少的, 特别是对样品以后硅烷化。</li>
	</ol>
</li>
	<li>
Hydrophobization
	<ol>
<li>
Hydrophobization FAS-17 硅烷化
		<ol>
<li>在蒸气相硅烷化之前, 用空气等离子体对样品进行 600s, 用 100 W 的等离子清洗剂处理。这个过程激活的表面功能组 (-OH 组) 作为链接器的硅烷分子。</li>
			<li>随后, 在玻璃培养皿中引入一些样品, 在吸管尖端的帮助下略微倾斜表面。在样品2旁边的培养皿上, 将两50µL 滴 1 h、1 h、2 h、13 h-癸-triethoxysilane (FAS-17) 存入。</li>
			<li>部分覆盖培养皿, 并将其放置在空气疏散干燥过夜。最后, 通风干燥。删除准备使用的示例。</li>
		</ol>
</li>
		<li>
Hydrophobization 氟聚合物(聚四氟乙烯) 沉积物
		<ol>
<li>用氟碳溶剂中的非晶态氟聚合物溶液, 在 1/20 (v/v)16的比例下, 将蚀刻样品16从约10厘米喷出。一个充满了溶液的香水扩散器可以用于这个目的。600s 在室温下晾干. 在清洁的无蚀刻表面上重复相同的过程, 使光滑的疏水性铝表面 (Ra = 0.25±0.03 µm)。</li>
			<li>应用第二层涂层, 并在110摄氏度烤箱中引入样品, 以确保600s 的溶剂完全去除, 并对含氟聚合物涂层进行交联。这一过程增加了耐久性, 正如制造商所指出的。</li>
		</ol>
</li>
		<li>
氧化铈-硬脂酸沉积 Hydrophobization
		<ol>
<li>清洁丙酮/乙醇/水中的蚀刻样品, 油脂实验它们在水中 300s, 并在压缩空气的流动中晾干。</li>
			<li>浸泡在50毫升的水溶液中含有2克三氯化铈水合物 (CeCl3· 7H2o) 的样品31 , 和3毫升的30% 过氧化氢 (H2O2)。在40摄氏度烤箱中浸泡在溶液中的样品1小时。</li>
			<li>把它从溶液中取出, 在蒸馏水中冲洗, 在100摄氏度的烤箱中600s。</li>
			<li>将样品浸入硬脂酸的30毫米乙醇溶液中 900s, 将其漂洗在乙醇中, 并在100摄氏度烤箱中将其烘干600s。 注: 一旦干燥冷却到室温, 样品就可以使用了。用氧化铈-硬脂酸涂层酸生产的 SH 表面以下简称铈-SA 涂层表面。</li>
		</ol>
</li>
	</ol>
</li>
</ol>2. 样品表征
<ol><li>
润湿分析
	<ol>
<li>
弹跳滴实验
		<ol>
<li>用弹跳滴实验法评价生产样品的憎水性程度13。通过从固定注射器中释放的针头, 其针位于表面上方 (10.1 厘米 0.2) 的位置, 量化所给出的反弹次数。下拉卷通常为4µL。</li>
			<li>用高速相机捕获序列。在高速视频采集软件中, 将采集速率固定在每秒4200张图像上, 曝光时间为235µs。</li>
			<li>录制完视频后, 从放置释放的那一刻起, 选择序列, 直到水滴已经与样品完全接触 (没有观察到更多的反弹)。保存视频文件。</li>
			<li>对于每个图像, 使用软件32检测放置配置文件。随后, 在播放视频序列时, 用肉眼来量化反弹的次数。在不容易识别的情况下, 计算静态降的质心位置的极大值 (大于 15-20%)。</li>
		</ol>
</li>
		<li>
倾斜板试验
		<ol>
<li>使用此测试仅对每个特定磨损测试所造成的损坏进行量化。采用实验室设计的摆式装置34, 分析了倾斜板试验 (TPE)33的水滴的剪切粘附性。</li>
			<li>使用侧面查看图像获取一个无柄下落放置在样本固定到一个倾平台。在图像采集过程中 (在 16 fps 的恒定捕获率) 下, 倾斜具有恒定角速度的平台 (5°)。因此, 每0.31°捕获一个 drop 图像。 注: 在特定倾角的上方, 在表面上的滴动 (滑动/滚出) 和这个状态可以用来同时确定前进和后退的接触角 (ACA 和 RCA)。产生接触线全局位移的最小倾角 (上坡和下坡接触线点同时移动) 称为滑动角 (SA)。SA 是从 TPE 这里报告的值。</li>
		</ol>
</li>
	</ol>
</li>
	<li>
粗糙度测量
	<ol>
<li>用白光共焦显微镜分析样品的显微粗糙度。设置扫描面积为 0.252 x 0.187 毫米每单一地形。</li>
		<li>每个样品至少取4个地形。使用放大50X 的目标, 以0.2 µm 的垂直步骤捕获200垂直平面. 确定 Ra 因子 (算术粗糙度振幅)。</li>
	</ol>
</li>
</ol>3. 耐久性试验
注: 分别评估每种磨损剂所引起的损伤。不要对每个样品进行多项磨损测试。
<ol><li>
横向磨损试验 注: 横向磨损试验 (见图 3a) 是通过商业线性磨料进行的。本试验旨在评估标准磨料尖端对表面的切向位移引起的磨损。该装置允许使用各种磨料, 设置广泛的应用压力, 横向速度和总数量的磨料循环35。<ol>
<li>使用制造商提供的标准橡胶磨料 CS-10。将速度固定在20周/分钟左右. 使用权重控制施加的压力。设置仪器所允许的最小压力, 对应于总重量为350克。 注: 考虑尖端宽度 (6.70±0.05 mm) 和使用的重量, 这些设置的相应的应用压力是97.3±1.4 帕。总磨损面积受尖端宽度和每个磨损周期总长度的限制。设置为38.1 毫米。</li>
		<li>对于每个样品, 评估1、2、3和5周期后的磨损。<ol>
<li>每次磨损处理后, 轻轻地刷表面 (使用制造商提供的刷子), 在水中冲洗, 并使用压缩空气吹。如2.1.2 节所述, 使用 TPE 评估润湿性能。</li>
		</ol>
</li>
	</ol>
</li>
	<li>
磨料颗粒冲击试验
	<ol>
<li>使用图 3b所示的设置进行粒子撞击测试, 这是由标准磨损测试 D968 的启发。从玻璃漏斗上释放30毫升 (约55克) 的磨料砂。在 (25±1) 厘米的表面定位其极端底部。</li>
		<li>使用漏斗丝锥直径 (12±1) 毫米和长度 (97±1) 毫米. 将漏斗垂直放置, 同时倾斜样品45°。撞击样品后, 将沙子收集在下面放置的容器中。</li>
		<li>一旦磨损循环, 用蒸馏水冲洗表面, 在压缩空气的流动中干燥, 并通过 TPE (2.1.2) 评估润湿性能。对每个示例重复此整个过程多达3次。</li>
	</ol>
</li>
	<li>
紫外线-臭氧表面降解试验
	<ol>
<li>使用臭氧清洗剂进行紫外线臭氧降解试验。在室温下对每个样品进行 600s, 重复一次循环。</li>
		<li>随后, 冲洗水中的表面, 用压缩空气晾干。</li>
		<li>评估2.1.2 节中描述的 TPE 的润湿性能, 以确定在紫外线照射后超疏水性的性能是否仍然存在。</li>
	</ol>
</li>
	<li>
水浸试验
	<ol>
<li>通过长时间浸泡在水中, 评估水接触引起的磨损。在100毫升的超纯水烧杯中介绍样品24小时。</li>
		<li>从水中取出样品, 用压缩空气干燥, 然后将它们放在一个120摄氏度的烤箱中 600s, 以确保从表面完全去除水。当表面完全干燥时, 使用2.1.2 节中描述的协议评估水暴露后的润湿性能。</li>
	</ol>
</li>
</ol>4. 防结冰效率评估
注: 防结冰效率评估是基于图 1所示的三方面。
<ol><li>
过冷水滴试验 注: 样品的过冷憎水性通过图 4a所示的设置进行测试。样品介绍在–20°c 的冷冻室内, 固定在倾斜 (30°) 平台的顶部。冰和蒸馏水的混合物在平衡 (在稳定的温度0°c) 被放置在结冰的房间外面。<ol>
<li>用蠕动泵将冷水泵入室内, 并在冰箱内循环, 然后每3秒降低1滴。单滴有大约50µL 的体积。</li>
		<li>一旦滴水过程开始, 每十年代捕获样本的横向图像, 以确定是否发生冰积。</li>
	</ol>
</li>
	<li>
冻结延时试验
	<ol>
<li>在前一节提到的同一冻结室内进行冻结延迟试验。</li>
		<li>确定在冷却过程中, 从室温降到大约-25 摄氏度的情况下, 在样品上沉积的无柄水滴的百分比。此测试的设置如图 4b所示。</li>
		<li>水平的样品 (零倾斜) 和存款无梗滴小心, 以避免翻滚。由于水滴在憎水性表面上的流动性很高, 所以在 SH 样品上放置了较低的数量。多次对 SH 表面重复实验。</li>
		<li>使用热探针监测温度和相对湿度。使用商用加湿器控制相对湿度 (RH)。当加湿器打开时, RH 大约是 95%, 当加湿器关闭时, 相对湿度会降低到大约40%。</li>
		<li>每个样品使用大约200滴30µL (下落结冰是一个随机现象, 并且分析要求使用大量滴)。 注: 因此, 这个测试使用较大的样本比那些用于其余的研究。在这种情况下, 大小是125毫米 x 62.5 毫米, 并调整协议, 以蚀刻样品或 hydrophobize 其表面到新的样本尺寸。</li>
		<li>把样品放在冰箱底部的一个隔离平台的顶部。轻轻地存入70滴每样的数组 (25 的超疏水性样品)。关闭冰箱并打开它。 注: 温度从室温降至约-25 摄氏度时线性下降。冷却速度取决于相对湿度。在低相对湿度 (未拔出加湿器), 整个过程大约需要2小时, 而它需要更少的时间 (约1小时), 如果加湿器连接。一旦温度低于0摄氏度, 水滴开始核核。</li>
		<li>计算每种温度下冻结的水滴数 (间隔为0.5 摄氏度), 直到所有水滴全部冻结为止。</li>
	</ol>
</li>
	<li>
冰粘附试验
	<ol>
<li>将必须应用的力量化为分离 (拉断) 一块冰, 并在每个样品上形成可控的接触区。使用图 4c所示的设置来执行这些测试。</li>
		<li>用剪刀把直径为10毫米的聚四氟乙烯管子切成28毫米高的圆筒。按下气缸对样品。用1.2 毫升蒸馏水填满它。在冷冻室中引入填充气缸, 等待1小时。 注: 一旦水完全冻结, 与气缸的样品是牢固固定在一个平台使用前锋板。</li>
		<li>用尼龙线将气缸与数字力计系在一起。这个气缸与螺纹连接的方式和圆柱体相对于螺纹的方向取决于所评估的类型 (剪切或拉伸) 附着力。把这个量规固定在一个机动的测试台上。关闭冷冻室, 等待600s。</li>
		<li>以恒定速度 (10 @ 0.5) 毫米/分钟取代试样。<ol>
<li>在机动测试台的控制面板中手动调整此速度。单击控制测功机读数的程序图标。按开始记录力。</li>
			<li>紧接着, 将测功机向上移动, 保持在电动支架控制面板内按下垂直位移底部。</li>
		</ol>
</li>
		<li>当测功机相对于试样的位移产生一个线的延伸和从样品中分离冰时, 单击停止并保存生成的数据文件。 注: 测量仪按时间对力进行监测。了解测功机偏移的速度 (10 毫米/分钟), 确定位移的力。这有助于确定断裂力 (最大挡力) 和每单位面积的附着力强度。</li>
		<li>在横向进行拉拔时, 对剪切附着力进行评价。这种情况下的力是平行应用于接触区 (见图 4b)。为此, 请垂直固定样品, 并使用金属环将气缸底座与螺纹连接。将这个环拉到测量器上, 直到试样从表面通过剪切位移分离出来。 注: 拉伸粘附试验评估峰值力和工作需要从表面分离一块冰时, 它是垂直拉。</li>
		<li>在这种情况下, 在气缸壁上钻两个小孔, 用来连接气缸和量规。然后, 垂直拉, 直到冰最终从表面分离出来。</li>
	</ol>
</li>
</ol>

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我们没有什么可透露的。

在本文中, 我们展示了在铝基板上产生憎水性表面的策略。此外, 我们还展示了其润湿性、粗糙度、耐久性和抗结冰性能的表征方法。
为了准备 SH 表面, 我们使用了两种策略。第一种策略采用适当的粗糙度, 通过酸蚀来实现 SH 表面的固有层次结构。这个过程是特别关键的, 这可能需要进一步的工作, 其他金属或铝基板具有不同的组成。寻找合适的蚀刻条件可能是一个问题, 通常?...

超疏水性 (SH) 表面对水的排斥能力是传统上提出的防止结冰1、2的一种解决方案的原因。然而, 对 sh 表面的抗结冰剂的适用性有担心: 1) 生产的高成本, 2) 那 superhydrophobicity 不总导致冰-phobicity3和 3) sh 表面的值得怀疑的耐久性4.超疏水性表面具有与其地形和化学成分有关的两个性质5: 它们是粗糙的, 具有特殊的地形特征;它们的表面能量很低 (本质上是疏水性的)。
疏水性表面的粗糙度有助于降低实际固液面积与表面接触面积的比值。水没有完全接触固体由于莲花效应6,7, 当下降休息或移动到表面粗糙。在这种情况下, 固液界面行为异种地两个化学领域: 固体表面本身和被困在固体和水之间的微小气泡8。由于空气斑块光滑, 其固有接触角为 180°, 因此, 防水程度与被困空气量有关。一些研究报告将分层的表面纹理与微粗糙和纳米结构结合在一起, 作为最佳的策略, 以提供更好的防水性能 (在固体-液体界面更大的空气存在)9。对于一些金属, 一个低成本的战略, 以创造两个层次的粗糙度特征是酸性蚀刻10,11。这个程序在工业中经常使用。随着某些酸浓度和蚀刻时间的推移, 金属表面显示出适当的分层粗糙度。通常情况下, 表面粗糙是通过改变酸浓度, 蚀刻时间, 或两个12的优化。金属的表面能量很高, 因此, 制造防水金属表面需要以后 hydrophobization。
Hydrophobization 一般通过疏水性膜沉积采用不同的方法: 硅烷化10、13、浸镀14、自旋涂层15、喷涂16或等离子沉积17.硅烷化已被建议18作为提高 SH 表面耐久性的最有希望的工具之一。与其他沉积技术不同, 硅烷化过程是基于硅 OH 基团与金属衬底的表面羟基10之间的共价键键。硅烷化过程的一个缺点是, 需要以前的金属基底活化, 以创造足够的羟基, 以高度的覆盖面和均匀度。最近提出的另一项生产抗超疏水性表面的策略是使用稀土涂层19,20。氧化铈涂层有两个属性, 这是合理的使用: 它们可以是本质上疏水性21, 他们是机械和化学的健壮。特别是, 他们被选择作为保护涂层的最重要的原因之一是他们的防腐能力20。
为了生产持久的 SH 金属表面, 考虑了两个问题: 表面纹理不能损坏, 疏水性薄膜/涂层必须牢固地锚定在基体上。表面通常暴露于磨损起源于横向磨损或颗粒撞击4。如果粗糙损坏, 可以大大减少憎水性。在极端环境下, 疏水性涂层可以部分地从表面上去除, 或者通过紫外线照射、湿度或腐蚀而化学降解。耐用的 SH 表面涂层的设计是涂层和表面工程的一个重要挑战。
对于金属, 最苛刻的要求之一是, 抗结冰能力是基于三相互关联的方面22 , 如图 1所示: 过冷憎水性, 冻结延迟, 低冰粘附。室外结冰发生时, 过冷的水, 典型的降雨下降, 接触固体表面, 并迅速冻结的异质核23。形成的冰 (霜) 牢固地附有在表面。因此, 避免结冰的第一步是减少固水接触时间。如果表面超疏水性, 在结冰前可能会从表面排出雨滴。此外, 已经证明, 在潮湿的条件下, 高接触角度的表面延迟冻结比那些低接触角24。由于这两个原因, SH 表面是最合适的表面, 以减轻结冰。然而, 超疏水性表面的寿命可能是一个关键点, 因为结冰条件通常是积极的25。一些研究得出结论, SH 表面不是减少冰粘附26的最佳选择。一旦冰形成在表面上, 它保持牢固地附有由于表面粗糙。粗糙度增加了冰面接触面积, 粗糙作为联锁剂26。建议使用耐用的 SH 表面, 以避免结冰, 如果没有冰的痕迹已经存在的表面上。
在这项工作中, 我们提出了几个协议, 以生产耐用的 SH 表面的金属基板。我们使用铝 (Al) 作为基体, 因为它是广泛应用于工业, 并纳入防结冰的性质特别适用于某些应用 (滑雪胜地设施, 航空等)。我们准备了三种类型的表面: 一种表面涂有氟聚合物涂层的质感铝面, 一种带有 fluorosilane 的质感铝表面硅烷化, 以及铝基板上的氧化铈-硬脂酸双层。类似的技术17,27,28,29提供 100-300 nm 薄膜厚度, 甚至单层薄膜。对于每个表面, 我们测量了它们的润湿性和进行磨损试验。最后, 我们分析了它们的抗结冰性能, 通过使用三测试来独立探测图 1所示的三属性。
我们的协议基于图 2所示的方案。制备了 SH 铝表面后, 对其润湿性能和形貌进行了分析, 以确定其憎水性和粗糙度特征。通过弹滴实验分析了其润湿性能, 这是一种与水的拉伸粘接相结合的技术。由于对降反射的观察是必需的, 这种技术仅适用于超疏水性表面13。对于每种表面处理, 我们准备了至少四个样品进行防结冰试验, 另外四个样品进行耐久性试验。通过测量润湿性能和粗糙度特征的损失, 分析了每次耐久性试验后所造成的损伤。类似的耐久性试验的建议, 在这项工作最近用于其他金属表面27,30。
关于防结冰试验, 本研究的目的是确定所生产的 SH 铝表面的使用是否方便作为防结冰剂。因此, 我们分析了两种控制样品的性能: a) 未经处理的 Al 样品 (光滑亲水性样品) 和 b) hydrophobized, 但不具有纹理的样品 (平滑疏水性样品)。出于同样的目的, 使用有质感但不 hydrophobized 的表面可能是有兴趣的。不幸的是, 这个表面是非常润湿的, 抗结冰测试不能为他们进行。

<table><tbody><tr><td>Hydrochloric acid, 37%</td><td>SICAL, S.A.</td><td>AC07411000</td><td>used for acid etching</td></tr><tr><td>1H,1H,2H,2H-Perfluorodecyltriethoxysilane, 97%</td><td>Sigma-Aldrich</td><td>658758</td><td>used for silanization with FAS-17</td></tr><tr><td>Dupont AF1600</td><td>Dupont</td><td>D10389631</td><td>used for fluropolymer deposition</td></tr><tr><td>FC-72</td><td>3M, Fluorinet</td><td>1100-2-93</td><td>used for fluropolymer deposition (flurocarbon solvent)</td></tr><tr><td>Cerium(III) chloride heptahydrate, 99.9%</td><td>Sigma-Aldrich</td><td>228931</td><td>used for Ceria coating deposition</td></tr><tr><td>Hydrogen peroxide solution, 30%</td><td>Sigma-Aldrich</td><td>H1009</td><td>used for Ceria coating deposition</td></tr><tr><td>Stearic acid, &amp;ge;98.5%</td><td>Sigma-Aldrich</td><td>S4751</td><td>used for Ceria coating deposition</td></tr><tr><td>Ethanol</td><td>SICAL, S.A.</td><td>16271</td><td>used throughout</td></tr><tr><td>Acetone</td><td>SICAL, S.A.</td><td>1090</td><td>used throughout</td></tr><tr><td>Aluminum sheets 0.5mm</td><td>MODULOR (Germany)</td><td>125993</td><td>substrates used throught</td></tr><tr><td>Micro-90 concentrated cleaning solution</td><td>Sigma-Aldrich</td><td>Z281506</td><td></td></tr><tr><td>Ultra pure Milli-Q water</td><td>Millipore</td><td>discontinued</td><td>used throughout</td></tr><tr><td>Plasma Etcher/Asher/Cleaner EMITECH K1050X</td><td>Aname</td><td>K1500XDEV-001</td><td>used throughout</td></tr><tr><td>PCC software</td><td>AMETEK</td><td>discontinued</td><td>sofware controlling the high speed camera Phantom MIRO 4</td></tr><tr><td>High Speed Camera Phantom Miro 4</td><td>AMETEK</td><td>discontinued</td><td>used for bouncing drop experiments</td></tr><tr><td>Open Loop PL&amp;micro; 2.32</td><td>UPC-CD6 &amp;amp; Sensofar Tech S.L.</td><td>version 2.32</td><td>Sofware controlling PL&amp;micro; Confocal Imaging Profiler</td></tr><tr><td>Pl&amp;micro;-Confocal Imaging Profiler 2300</td><td>Sensofar Tech S.L.</td><td>discontinued</td><td>used for roughness measurements</td></tr><tr><td>TABER 5750 LINEAL ABRASER</td><td>TABER</td><td>5750</td><td>used for lateral abrasion tests</td></tr><tr><td>Abbrasive sand: ASTM 20-30 SAND C778</td><td>U.S. SILICA COMPANY (USA)</td><td>1-800-635-7263</td><td>used for abrasive partcile impact tests</td></tr><tr><td>Ozone cleaner: PSDP-UV4T, Digital UV Ozone System</td><td>Novascam</td><td>discontinued</td><td>UV-ozone degradation test</td></tr><tr><td>Peristalitic Pump GILSON 312, France</td><td>GILSON (France)</td><td>discontinued</td><td>used for water dripping test</td></tr><tr><td>Nylon thread</td><td>Dracon fishing line, Izorline internacional, inc. (USA)</td><td>discontinued</td><td>used for ice adhesion tests</td></tr><tr><td>Digital force gauge (ZTA-200N, ZTA Series</td><td>IMADA (USA)</td><td>370199</td><td>used for ice adhesion tests</td></tr><tr><td>Motorized test stand I, MH2-500N-FA</td><td>IMADA (USA)</td><td>366942</td><td>used for ice adhesion tests</td></tr><tr><td>Force Recorder Professional</td><td>IMADA (USA)</td><td>version 1.0.2</td><td>software provided by IMADA to register the force</td></tr><tr><td>HYGROCLIP XD - STANDARD PROBE</td><td>Rotronic</td><td>discontinued</td><td>Temperature and humidity probe</td></tr><tr><td>HW3 Lite software</td><td>Rotronic</td><td>version 2.1.2</td><td>Sofware controlling the HYGROCLIP Probe</td></tr></tbody></table>

fabrication of superhydrophobic metal surfaces for anti-icing applications

本文介绍了几种生产超疏水性金属表面的方法。铝因其在工业中的广泛应用而被选为金属基体。通过弹滴实验分析了产生表面的润湿性, 并用共焦显微技术对其形貌进行了分析。此外, 我们还展示了测量其耐久性和抗结冰性能的各种方法。超疏水性表面保持一种特殊的质地, 必须保存, 以保持其防水。为了制造耐用的表面, 我们遵循了两种策略来整合一种耐药性的纹理。第一种策略是通过酸性蚀刻直接将粗糙度与金属基体结合在一起。表面挤压后, 硅烷化或含氟聚合物沉积物降低了表面能量。第二种策略是氧化铈层 (表面挤压后) 的生长, 以提高表面硬度和耐腐蚀性。用硬脂酸膜降低了表面能量。
超疏水性表面的耐久性通过粒子撞击试验、横向磨损的机械磨损和紫外线-臭氧电阻来检验。通过研究消除过冷水、冻结延迟和冰粘附能力, 探讨了抗结冰性能。

本文研究的 SH 表面的润湿性和粗糙度特性如图 5所示。每个样本的平均反弹次数显示在图 5a中, 平均粗糙度如图 5b所示。粗糙度和润湿性之间没有相关性。聚四氟乙烯涂层试样的反弹次数与 Ce 样品一致。然而, Ce SA 的样本显然是粗糙的 (~ 40% 更大的 Ra 值)。相比之下, FAS-17 样品的 Ra 值与聚四氟乙烯非常相似...

Watch this Scientific Journal Video about Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications at JoVE.com

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

我们阐述了几种生产超疏水性金属表面的方法, 并探讨了它们的耐久性和抗结冰性能。

防结冰用超疏水性金属表面的制备

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...

fabrication-superhydrophobic-metal-surfaces-for-anti-icing

Research

JoVE Journal

Engineering

8.4K 次观看.  University of Granada. 我们阐述了几种生产超疏水性金属表面的方法, 并探讨了它们的耐久性和抗结冰性能。

视频: Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

科研

工程学

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where interfacial tension is a dominant force. A variety of methods exist for controlling the interfacial tension of aqueous and organic liquids on this scale; however, these techniques have limited utility for liquid metals due to their large interfacial tension.
Liquid metals can form soft, stretchable, and shape-reconfigurable components in electronic and electromagnetic devices. Although it is possible to manipulate these fluids via mechanical methods (e.g., pumping), electrical methods are easier to miniaturize, control, and implement. However, most electrical techniques have their own constraints: electrowetting-on-dielectric requires large (kV) potentials for modest actuation, electrocapillarity can affect relatively small changes in the interfacial tension, and continuous electrowetting is limited to plugs of the liquid metal in capillaries.
Here, we present a method for actuating gallium and gallium-based liquid metal alloys via an electrochemical surface reaction. Controlling the electrochemical potential on the surface of the liquid metal in electrolyte rapidly and reversibly changes the interfacial tension by over two orders of magnitude ( &#820;500 mN/m to near zero). Furthermore, this method requires only a very modest potential (&#60; 1 V) applied relative to a counter electrode. The resulting change in tension is due primarily to the electrochemical deposition of a surface oxide layer, which acts as a surfactant; removal of the oxide increases the interfacial tension, and vice versa. This technique can be applied in a wide variety of electrolytes and is independent of the substrate on which it rests.

We present a method to control the interfacial energy of a liquid metal in an electrolyte via electrochemical deposition (or removal) of a surface oxide layer. This simple method can control the capillary behavior of gallium-based liquid metals by tuning the interfacial energy rapidly, significantly, and reversibly using modest voltages.

方法通过表面氧化还原操纵液态金属的表面张力

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where ...

化学

TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method

This manuscript proposes a soft-chemistry method to develop superhydrophobic and highly IR-reflective hollow glass microspheres (HGM). The anatase TiO2 and a superhydrophobic agent were coated on the HGM surface in one step. TBT and PFOTES were selected as the Ti source and the superhydrophobic agent, respectively. They were both coated on the HGM, and after the hydrothermal process, the TBT turned to anatase TiO2. In this way, a PFOTES/TiO2-coated HGM (MCHGM) was prepared. For comparison, PFOTES single-coated HGM (F-SCHGM) and TiO2 single-coated HGM (Ti-SCHGM) were synthesized as well. The PFOTES and TiO2 coatings on the HGM surface were demonstrated through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive detector (EDS) characterizations. The MCHGM showed a higher contact angle (153&#176;) but a lower sliding angle (16&#176;) than F-SCHGM, with a contact angle of 141.2&#176; and a sliding angle of 67&#176;. In addition, both Ti-SCHGM and MCHGM displayed similar IR reflectivity values, which were about 5.8% higher than the original HGM and F-SCHGM. Also, the PFOTES coating barely changed the thermal conductivity. Therefore, F-SCHGM, with a thermal conductivity of 0.0479 W/(m&#183;K), was quite like the original HGM, which was 0.0475 W/(m&#183;K). MCHGM and Ti-SCHGM were also similar. Their thermal conductivity values were 0.0543 W/(m&#183;K) and 0.0543 W/(m&#183;K), respectively. The TiO2 coating slightly increased the thermal conductivity, but with the increase in reflectivity, the overall heat-insulation property was enhanced. Finally, since the IR-reflecting property is provided by the HGM coating, if the coating is fouled, the reflectivity decreases. Therefore, with the superhydrophobic coating, the surface is protected from fouling, and its lifetime is also prolonged.

TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method

This manuscript proposes a soft-chemistry method to synthesize superhydrophobic, TiO2-coated hollow glass microspheres (HGM) with high IR-reflective properties.

二氧化钛<sub&gt; 2</sub与由软化学法合成的超疏水性和高IR反射属性&gt;涂覆的空心玻璃微球

This manuscript proposes a soft-chemistry method to develop superhydrophobic and highly IR-reflective hollow glass microspheres (HGM). The anatase TiO2 ...

Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the hybrid wettable pattern. Hybrid wettable patterns were produced by coating superhydrophilic SiO2 on a masked, hydrophobic, cylindrical copper surface. Using de-ionized (DI) water as the working fluid, pool-boiling heat-transfer studies were conducted on the different surface-treated copper cylinders of a 25-mm diameter and a 40-mm length. The experimental results showed that the number of interlines and the orientation of the hybrid wettable pattern influenced the wall superheat and the HTC. By increasing the number of interlines, the HTC was enhanced when compared to the plain surface. Images obtained from the charge-coupled device (CCD) camera indicated that more bubbles formed on the interlines as compared to other parts. The hybrid wettable pattern with the lowermost section being hydrophobic gave the best heat-transfer coefficient (HTC). The experimental results indicated that the bubble dynamics of the surface is an important factor that determines the nucleate boiling.

Pool-boiling heat-transfer experiments were carried out to observe the effects of hybrid wettable patterns on the heat-transfer coefficient (HTC). The parameters of investigation are the number of interlines and the pattern orientation of the modified wettable surface.

在圆柱面池沸腾传热强化与混合可湿性模式

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the ...

Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 &#176;C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

Slippery surfaces provide a new way to solve the adhesion problem. This protocol describes how to fabricate slippery surfaces at high temperatures. The results demonstrate that the slippery surfaces showed anti-wetting for liquids and a remarkable anti-adhesion effect on soft tissues at high temperatures.

不锈钢滑面的制备及高温抗粘接性能研究

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A ...

Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance

Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. However, the main issue limiting their applicability is their poor stability in humid conditions. The common methods to overcome this problem involve the formation of strong metal-linker bonds by using highly charged metals, which is limited to a number of structures, the introduction of alkylic groups to the framework by post-synthetic modification (PSM) or chemical vapour deposition (CVD) to enhance overall hydrophobicity of the framework. These last two usually provoke a drastic reduction of the porosity of the material. These strategies do not permit to exploit the properties of the MOF already available and it is imperative to find new methods to enhance the stability of MOFs in water while keeping their properties intact. Herein, we report a novel method to enhance the water stability of MOF crystals featuring Cu2(O2C)4&#160;paddle-wheel units, such as HKUST (where HKUST stands for Hong Kong University of Science &#38; Technology), with the catechols functionalized with alkyl and fluoro-alkyl chains. By taking advantage of the unsaturated metal sites and the catalytic catecholase-like activity of CuII ions, we are able to create robust hydrophobic coatings through the oxidation and subsequent polymerization of the catechol units on the surface of the crystals under anaerobic and water-free conditions without disrupting the underlying structure of the framework. This approach not only affords the material with improved water stability but also provides control over the function of the protective coating, which enables the development of functional coatings for the adsorption and separations of volatile organic compounds. We are confident that this approach could also be extended to other unstable MOFs featuring open metal sites.

Robust functional catechol coatings were produced in one step by direct reaction of the material known as HKUST with synthetic catechols under anaerobic conditions. The formation of homogeneous coatings surrounding the entire crystal is ascribed to the biomimetic catalytic activity of Cu(II) dimers on the external surface of the crystals.

金属-有机框架的表面功能化改善防潮性能

Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. ...

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

制造超疏水高分子材料生物医学应用

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

生物工程

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping microtextures (GEMs) on them comprising cavities and pillars with reentrant and doubly reentrant features. Specifically, we use SiO2/Si as the model system and share protocols for two-dimensional (2D) designing, photolithography, isotropic/anisotropic etching techniques, thermal oxide growth, piranha cleaning, and storage towards achieving those microtextures. Even though the conventional wisdom indicates that roughening intrinsically wetting surfaces (&#952;o &#60; 90&#176;) renders them even more wetting (&#952;r &#60; &#952;o &#60; 90&#176;), GEMs demonstrate liquid repellence despite the intrinsic wettability of the substrate. For instance, despite the intrinsic wettability of silica &#952;o &#8776; 40&#176; for the water/air system, and &#952;o &#8776; 20&#176; for the hexadecane/air system, GEMs comprising cavities entrap air robustly on immersion in those liquids, and the apparent contact angles for the droplets are &#952;r &#62; 90&#176;. The reentrant and doubly reentrant features in the GEMs stabilize the intruding liquid meniscus thereby trapping the liquid-solid-vapor system in metastable air-filled states (Cassie states) and delaying wetting transitions to the thermodynamically-stable fully-filled state (Wenzel state) by, for instance, hours to months. Similarly, SiO2/Si surfaces with arrays of reentrant and doubly reentrant micropillars demonstrate extremely high contact angles (&#952;r &#8776; 150&#176;&#8211;160&#176;) and low contact angle hysteresis for the probe liquids, thus characterized as superomniphobic. However, on immersion in the same liquids, those surfaces dramatically lose their superomniphobicity and get fully-filled within &#60;1 s. To address this challenge, we present protocols for hybrid designs that comprise arrays of doubly reentrant pillars surrounded by walls with doubly reentrant profiles. Indeed, hybrid microtextures entrap air on immersion in the probe liquids. To summarize, the protocols described here should enable the investigation of GEMs in the context of achieving omniphobicity without chemical coatings, such as perfluorocarbons, which might unlock the scope of inexpensive common materials for applications as omniphobic materials. Silica microtextures could also serve as templates for soft materials.

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

This work presents microfabrication protocols for achieving cavities and pillars with reentrant and doubly reentrant profiles on SiO2/Si wafers using photolithography and dry etching. Resulting microtextured surfaces demonstrate remarkable liquid repellence, characterized by robust long-term entrapment of air under wetting liquids, despite the intrinsic wettability of silica.

通过雕刻包含可重入和双重入的腔或柱的气体镶入微纹理来渲染 SiO2/Si 曲面全功能性

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping ...

Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination

Desalination through direct contact membrane distillation (DCMD) exploits water-repellent membranes to robustly separate counterflowing streams of hot and salty seawater from cold and pure water, thus allowing only pure water vapor to pass through. To achieve this feat, commercial DCMD membranes are derived from or coated with water-repellent perfluorocarbons such as polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF). However, the use of perfluorocarbons is limiting due to their high cost, non-biodegradability, and vulnerability to harsh operational conditions. Unveiled here is a new class of membranes referred to as gas-entrapping membranes (GEMs) that can robustly entrap air upon immersion in water. GEMs achieve this function by their microstructure rather than their chemical make-up. This work demonstrates a proof-of-concept for GEMs using intrinsically wetting SiO2/Si/SiO2 wafers as the model system; the contact angle of water on SiO2 is &#952;o &#8776; 40&#176;. Silica-GEMs had 300 &#956;m-long cylindrical pores whose diameters at the (2 &#956;m-long) inlet and outlet regions were significantly smaller; this geometrically discontinuous structure, with 90&#176; turns at the inlets and outlets, is known as the &#34;reentrant microtexture&#34;. The microfabrication protocol for silica-GEMs entails designing, photolithography, chrome sputtering, and isotropic and anisotropic etching. Despite the water loving nature of silica, water does not intrude silica-GEMs on submersion. In fact, they robustly entrap air underwater and keep it intact even after six weeks (&#62;106 seconds). On the other hand, silica membranes with simple cylindrical pores spontaneously imbibe water (&#60; 1 s). These findings highlight the potential of the GEMs architecture for separation processes. While the choice of SiO2/Si/SiO2 wafers for GEMs is limited to demonstrating the proof-of-concept, it is expected that the protocols and concepts presented here will advance the rational design of scalable GEMs using inexpensive common materials for desalination and beyond.

Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination

Presented here is a stepwise protocol for realizing gas-entrapping membranes (GEMs) from SiO2/Si wafers using integrated circuit microfabrication technology. When silica-GEMs are immersed in water, the intrusion of water is prevented, despite the water-loving composition of silica.

气体夹膜的概念验证，源自爱水的SiO 2/Si/SiO2晶圆，用于绿色海水淡化

Desalination through direct contact membrane distillation (DCMD) exploits water-repellent membranes to robustly separate counterflowing streams of hot and ...

Fabrication of Gradient Nanopattern by Thermal Nanoimprinting Technique and Screening of the Response of Human Endothelial Colony-forming Cells

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular reactions. However, it is difficult to determine the relation between the size of a nanostructure and the responses of cells owing to the lack of proper screening tools. Here, we show the development of reproducible and cost-effective gradient nanopattern plates for the manipulation of cellular responses. Using anodic aluminum oxide (AAO) as a master mold, gradient nanopattern plates with nanopillars of increasing diameter ranges [120-200&#8239;nm (GP 120/200), 200-280&#8239;nm (GP 200/280), and 280-360&#8239;nm (GP 280/360)] were fabricated by a thermal imprinting technique. These gradient nanopattern plates were designed to mimic the various sizes of nanotopography in the ECM and were used to screen the responses of human endothelial colony-forming cells (hECFCs). In this protocol, we describe the step-by-step procedure of fabricating gradient nanopattern plates for cell engineering, techniques of cultivating hECFCs from human peripheral blood, and culturing hECFCs on nanopattern plates.

Here, we present a protocol for the fabrication of gradient nanopattern plates via thermal nanoimprinting and the method of screening responses of human endothelial progenitor cells to the nanostructures. By using the described technology, it is possible to produce a scaffold that can manipulate cell behavior by physical stimuli.

热 Nanoimprinting 技术制备梯度 Nanopattern 及其对人血管内皮细胞菌落形成的响应筛选

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular ...

防结冰用超疏水性金属表面的制备

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