不同基底温度下铝基超疏水表面的抗结冰性能实验

本文利用刻蚀方法制备了铝基超疏水表面,在环境温度20℃、相对湿度60%下进行了不同基底温度(-15℃、-20℃、-25℃、-30℃)超疏水表面的静态和动态低温液滴抗结冰性能实验研究。结果表明:超疏水表面在液滴静、动态下均表现出良好抗结冰性能;在静态液滴抗结冰实验中,随着冷表面温度的降低,超疏水表面延缓结冰的时间快速下降,当基底温度为-25℃时,其抗结冰性能发生突变,并随冷表面温度的进一步降低而表现恶化;在动态液滴抗结冰实验中,当冷表面温度为-15℃和-20℃时,低温液滴能快速从低温表面弹离,而当冷表面温度为-25℃和-30℃时,低温液滴不能从超疏水表面弹离,滞留在超疏水表面上,且快速在其上冻结,超疏水表面失去了抗结冰性能。基于相关相变成核理论,分析了其抗结冰的机理。为超疏水表面在冬季空调室外换热器上的应用提供一定参考。     

超疏水表面防结冰结霜性能的研究进展

利用超疏水表面可以防止或减少金属表面结冰结霜,在制备防结冰结霜表面中得到了广泛深入地研究。超疏水表面一般是利用其自身表面的粗糙结构和低表面能来使得液滴无法在其表面长时间停留而获得超疏水性能,但是液滴在低温和大湿度以及液滴在高高度撞击超疏水表面条件下会使超疏水表面的抗结冰结霜性能明显降低。针对这种情况,综述了超疏水表面在这方面的进展来探讨提高其抗结冰结霜性能的可能途径和方法。     

铝基体超疏水表面结冰结霜特性研究

采用中性电解液,通过电化学加工技术及氟化处理方法制备出铝基体超疏水表面,接触角达160°,滚动角小于5°,并在其上进行了结冰和结霜研究.在不同实验条件下研究超疏水表面的形貌、霜高随时间的变化,并与相同条件下的普通铝表面、吸水性表面进行了对比.结果表明,该超疏水表面经过50多次结霜、除霜后,仍具有很好的超疏水性能,表现出良好的重复性和耐久性;与普通铝表面相比,铝基体超疏水表面具有明显的抗结冰结霜性能,霜晶先出现在四周边缘处并逐渐蔓延到中间,但抑霜能力随着冷表面温度的降低而减小;与吸水性表面相比,超疏水表面在抗结冰结霜的同时能有效抑制表面质量的增加.     

铝基体超疏水表面的抗结冰结霜效果分析

增加接触角是提高表面抗结冰结霜能力的重要方法.借助电化学加工和氟化处理获得铝基体超疏水表面,该表面具有二元微纳米复合结构,干燥时水滴在其上的接触角为160°,滚动角小于5°,处于Cassie-Baxter状态.在自制的半导体制冷台上,观测冷表面温度为-5.2 ℃时,铝基体超疏水表面的结霜过程,并将其与普通铝表面进行了对比,发现铝基体超疏水表面的四周边缘处先出现霜晶并逐渐蔓延到整个表面,与普通铝表面相比具有显著的抗结冰结霜性能.最后对铝基体超疏水表面的边缘效应和抗结冰结霜机理进行了分析.     

表面微结构设计对材料疏水及防冰性能影响研究

以硅氧烷为疏水剂,采用浸渍法在具有开放及封闭微结构的金属铝板上制备了超疏水表面,系统考查了表面微结构设计对材料疏水及防冰性能的影响。结果表明,超疏水表面静态接触角随结除冰次数的增加而减少,滚动角随结除冰次数的增加而增大,且在多个结冰除冰循环后,表面开放微结构的金属铝板丧失其超疏水性,表面封闭微结构的金属铝板仍保持其超疏水性。进一步实验研究表明,在多个结冰除冰循环后,在相同结冰条件下,水滴在表面为开放微结构的金属铝板上的结冰时间远长于表面为封闭结构的金属铝板。     

超疏水铜表面的制备及其抑冰性能研究

通过在铜片表面沉积蜡烛灰涂层成功构建了纳米结构超疏水表面,该表面在室温(23±2)℃下与水滴的接触角为160°,滚动角为1°。研究了超疏水铜表面在低温条件下的抑冰性能,结果表明,在(-40±10)℃时将50μL水滴从5cm的高处滴至普通的铜表面2s开始结冰,而滴至超疏水铜试样(3cm×3cm×0.2mm)表面的水滴可以快速滚动,从滚动直至滚落超疏水铜试样表面所需的时间比水滴开始结冰所需的时间(50s)短,水滴未在超疏水铜试样表面结冰。通过测试冰与材料的黏附力,发现普通铜表面与冰的黏附力是超疏水铜表面与冰的黏附力的4.9倍。此外,在融冰的过程中发现,结冰的水滴在常温下稍微融化,在微风的作用下或稍微倾斜6°就能从超疏水铜表面滑落下来,表明超疏水铜表面比普通铜表面具有更好的抑冰性能。     

飞秒激光参数对硅橡胶表面结构与防冰性能影响的研究

目的 采用飞秒激光刻蚀硅橡胶表面,获得表面结构较优、润湿性能与防冰性能优异的超疏水硅橡胶表面。方法 通过控制变量,设计单因素试验,研究飞秒激光参数(填充间距、能量密度、扫描速度)对硅橡胶表面结构的影响规律。基于正交试验设计和极差分析获得使表面结构规整且表面粗糙度最大的相对最优工艺参数,研究飞秒激光参数对表面粗糙度的影响主次顺序。结果 飞秒激光刻蚀硅橡胶的相对最佳工艺参数如下:能量密度为5 J/cm²,扫描速度为200 mm/s,填充间距为20 μm。最优参数组下激光刻蚀的超疏水硅橡胶表面粗糙度达到最大值5.954 μm,具有规整的峰状凸起与微纳结构和优异的超疏水性能,水接触角高达165.3°,滚动角低至2.6°。该超疏水硅橡胶表面具有优异的防冰性能,在低温高湿环境下,与未处理的硅橡胶表面相比,结冰时间由67 s延长至312 s,冰黏附强度由39.6 kPa降低至7.4 kPa。超疏水硅橡胶还具有良好的循环除冰性能,经20次结冰/除冰循环后,冰黏附强度仍不超过20 kPa;此外,该表面还具有优异的耐腐蚀性能和良好的耐磨损性能。结论 飞秒激光增大能量密度和减小扫描速度会使激光刻蚀宽度增大,要避免纵向条纹,应控制填充间距不超过激光刻蚀宽度。激光参数优化后刻蚀出的超疏水硅橡胶表面具备优异的防冰性能,并且机械与化学稳定性较好,在恶劣环境中的防冰领域,具有广阔的应用前景。     

溶胶凝胶法铝基超疏水表面的制备及其防覆冰性能

利用溶胶凝胶法(Sol-Gel)在铝基体上制得超疏水表面,并用自制的基于二级制冷方式的材料样品结冰状况实时采集控制系统对单个水滴进行定量定性防覆冰测试。使用红外光谱仪、扫描电镜对表面形貌及结构进行表征。制得的超疏水表面静态接触角高达169.17°,滚动角3~5°,具有极好的超疏水性和低粘附力。防覆冰实验显示超疏水铝片经过65 min,在-8.3℃时才结冰,比未经过处理的普通铝片结冰时间延长了52 min,温度也要低4.2℃,显示出优异的抗结冰性能。为超疏水在防覆冰领域的应用提供了一定的参考价值。     

金属基体超疏水表面抗凝露抗结霜特性的研究进展

本文综述了近几年金属基体超疏水表面抗凝露抗结霜特性的研究进展。总结了金属基体超疏水表面抗凝露抗结霜特性的实验研究,指出微纳米复合结构和纳米结构超疏水表面都有抗凝露抗结霜性能,但两者性能优劣并无定论。关于超疏水表面抗凝露抗结霜的机理,部分研究者认为是超疏水表面凝结水形成有较大能量势垒,另一部分研究者认为纳米结构超疏水表面液体自迁移现象对其抗凝露抗结霜有重要的影响。目前,超疏水表面与空气换热的研究还不够充分,这方面的深入研究能够为超疏水表面应用到微通道换热器中提供理论基础。     

沥青路面超疏水抗凝冰材料研究进展

超疏水材料作为一种具有特殊表面性质的新型智能仿生材料,因其优良的疏水防冰性能,已广泛应用于航天、电力等领域,但在公路交通领域尚处于探索研究阶段.沥青路面超疏水抗凝冰材料属于主动抑冰融雪技术,能够延缓道路结冰,降低冰层与路面间的黏附力,为冬季沥青路面的疏水防冰提供新思路.目前,沥青路面超疏水材料抗凝冰理论及技术尚不成熟,主要通过加入低表面能材料和提高表面粗糙度两种方式构建超疏水表面,从而缩短液滴与界面接触时间、降低凝固点、延迟结冰时间以及降低冰层与基质表面的粘结力,从而达到疏水防冰的目的.路用超疏水材料主要包括疏水型融雪抑冰材料和抗覆冰超疏水涂层材料两种.沥青路面超疏水涂层承受复杂外界因素的综合作用,其耐磨性、长期疏水防冰性能受到广大研究学者的关注.本文介绍了"冰-路"界面粘结机理;按加载方式将"冰-路"粘结强度测试方法分为直接拉拔法、离心力法、冲击法、间接拉伸法、剪切应力法等.超疏水材料的长效性问题主要表现为机械稳定性和耐磨性应用效果不佳.沥青路面表面结构复杂,影响因素众多,从实际工程应用来看,沥青路面超疏水抗凝冰材料的制备技术、评价方法和工程应用长效性仍需进一步研究.本文归纳了沥青路面超疏水抗凝冰材料的研究进展,分别对超疏水材料抗凝冰理论、沥青路面超疏水材料制备方法、沥青路面超疏水涂层处治技术、超疏水涂层抗凝冰性能测试方法和超疏水材料长效性等方面进行了介绍,分析了沥青路面超疏水抗凝冰材料面临的问题并展望了其前景,以期为制备耐久、环境友好的新型沥青路面超疏水抗凝冰材料提供参考.     

冷表面上水滴结冰问题的实验研究进展

文章对冷表面上水滴沉积结冰和撞击结冰微物理过程的实验研究进展进行总结。提出影响水滴结冰的因素主要有冷表面、环境条件、水滴自身和附加力/场,重点介绍了低能表面抑冰性能和对流情况对水滴结冰影响的研究现状。最后,指出不同因素对水滴结冰的影响规律,超疏水表面抑冰性能的优化,以及结冰过程主动控制方法的探索可以开展深入研究,为进一步研究和应用提供参考。     

Design and development of anti-icing textile surfaces

An anti-icing material can be created by mimicking one of nature’s best known performances superhydrophobicity that is observed at many plant leaves. The anti-icing properties of a superhydrophobic surface depend on the surface morphology as well as the surface tension of the substrate. This implies that both the chemistry and the topography of the anti-icing coating material are important. Therefore, the relationship between the anti-icing properties and the morphology of a superhydrophobic surface should be understood and the study has to be extended beyond the bio-inspired superhydrophobic properties of the materials to similar properties toward ice. In this research, fluorosilane-treated superhydrophobic textile nonwoven fabric is prepared via wet-processing, and the anti-icing properties of the surface are observed and compared to those of three controls: an untreated fabric, a fluorosilane-treated smooth surface, and an untreated film. In order to evaluate anti-icing properties of superhydrophobic surfaces, super-cooled water was dropped on the surface of the prepared superhydrophobic fabric and all three controls. In addition, water drops were deposited on a superhydrophobic surface and the controls, and then the samples along with water drops were placed in a freezer to make the water drops completely freeze. After the samples were removed from the freezer, they were placed on a plate inclined at 45° to compare the ice removal process of the superhydrophobic surface with those of the controls. It was found that a superhydrophobic surface, which was created by combining low surface energy and micro/nano rough structures, could provide anti-icing properties to the surface.     

超疏水沥青混凝土抗凝冰性能及评价

引入超疏水设计理念,制备了具有超疏水抗凝冰性能的沥青混凝土试件。通过模拟试验和理论分析相结合,开展了超疏水沥青混凝土抗凝冰性能研究,测定了普通试件及超疏水试件抗凝冰性能差异,分析了不同工况下超疏水沥青混凝土试件的抗凝冰性能。通过接触角测定及表面能计算,评价了超疏水沥青混凝土的防冰、疏冰性能。结果表明,超疏水沥青混凝土可有效促进液滴滚落,滚落率高达80%。通过自行设计的落锤冲击试验间接测定了超疏水沥青混凝土试件的"冰-路"附着力,仅为普通沥青混凝土试件的38.5%。基于不同工况,降雪环境下超疏水沥青混凝土试件冰的残留率最低。接触角试验和表面能计算表明,超疏水沥青混凝土的表面能为1.97mJ/m2,仅为普通沥青混凝土的5.1%,体现了良好的抗凝冰性能。     

An Extreme-Environment-Resistant Self-Healing Anti-Icing Coating

Anti-icing coatings on outdoor infrastructures and transportations inevitably suffer from surface injuries, especially in extreme weather events (e.g., freezing weather or acid rain). The coating surface damage can result in anti-icing performance loss or even icing promotion. The development of anti-icing coatings that enables self-healing in extreme conditions is highly desired but still challenging. Herein, an extreme-environment-resistant self-healing anti-icing coating is developed by integrating fluorinated graphene (FG) into a supramolecular polymeric matrix. The coating exhibits both anti-icing and deicing performance (ice nucleation temperature is ≈−30.3 °C; ice shear strength is ≈48.7 kPa), mainly attributable to the hydrophobic FG and silicone-based supramolecular material. Notably, owing to the crosslinking polymeric network with various dynamic bonds, this coating can sustain anti-icing/deicing performance after autonomous self-healing under harsh conditions including low temperature (−20 °C), strong acid (pH = 0), and strong alkali (pH = 14) environments. This coating paves the way to meet the anti-icing demand in open air, especially for the infrastructures in polar regions or acid/alkali environments.     

纳米氟碳涂层抑制过冷却器冰堵的机理

冰浆由于良好的热物特性,在许多领域得到广泛的应用,其制取方式也成为关注的焦点。过冷水动态制冰是目前最有发展前途的制取冰浆方式之一,但其主要缺陷是过冷却器易发生冰堵。在此,基于水溶液结晶的机理,从影响过冷却器冰堵的因素出发,指出纳米氟碳表面改性材料可改善表面状况,有效抑制壁面结冰,减少制冰过程中的冰堵问题,提高整个系统的制冰效率,降低能耗。纳米氟碳涂层抑制过冷却器冰堵的机理对进一步深化和开发新一代防结冰技术有一定意义。     

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。     

Ice accretion on superhydrophobic aluminum surfaces under low-temperature conditions

An icephobic surface is always desirable for high voltage overhead transmission lines to reduce ice formation on their aluminum surface, especially in a low temperature and high humidity environment. This work studied the effects of two hydrophobic coatings when applied on aluminum surfaces under cold and raining conditions in an artificial climatic chamber. Compared with bare hydrophilic aluminum surfaces, the aluminum surfaces coated with hydrophobic room temperature vulcanized silicone rubber (RTV SR) did resist ice formation but was covered by a layer of ice after 30 min of spraying supercooled water. However, a superhydrophobic coating can largely prevent ice formation on the surface except a few ice growth spots at a working temperature of − 6 °C. Furthermore, such coating keeps average water contact angles larger than 150° even at a working temperature of − 10 °C. This highly icephobic performance of the above samples is mainly attributed to the superhydrophobic property of the coating, which was obtained on micronanoscale structured aluminum surfaces after the low surface-energy stearic acid treatment.     

金属基体超疏水表面制备及应用的研究进展

在介绍润湿性相关理论的基础上,综述了国内外金属基体超疏水表面的制备方法及应用,重点讨论了阳极氧化法、电化学沉积法、化学腐蚀法、化学沉积法、一步浸泡法、热氧化法、模板法、复合法等,及超疏水表面在响应开关、自清洁、流体减阻、耐腐蚀、防冰霜、油水分离、微型水上运输器等方面的应用,最后评述了各种方法的特点,提出了在金属基体上制...     

A Review of Smart Superwetting Surfaces Based on Shape-Memory Micro/Nanostructures

Bioinspired smart superwetting surfaces with special wettability have aroused great attention from fundamental research to technological applications including self-cleaning, oil–water separation, anti-icing/corrosion/fogging, drag reduction, cell engineering, liquid manipulation, and so on. However, most of the reported smart superwetting surfaces switch their wettability by reversibly changing surface chemistry rather than surface microstructure. Compared with surface chemistry, the regulation of surface microstructure is more difficult and can bring novel functions to the surfaces. As a kind of stimulus-responsive material, shape-memory polymer (SMP) has become an excellent candidate for preparing smart superwetting surfaces owing to its unique shape transformation property. This review systematically summarizes the recent progress of smart superwetting SMP surfaces including fabrication methods, smart superwetting phenomena, and related application fields. The smart superwettabilities, such as superhydrophobicity/superomniphobicity with tunable adhesion, reversible switching between superhydrophobicity and superhydrophilicity, switchable isotropic/anisotropic wetting, slippery surface with tunable wettability, and underwater superaerophobicity/superoleophobicity with tunable adhesion, can be obtained on SMP micro/nanostructures by regulating the surface morphology. Finally, the challenges and future prospects of smart superwetting SMP surfaces are discussed.     

On ice-releasing properties of rough hydrophobic coatings

In this work, ice repellency of rough hydrophobic coatings based on different materials and with different surface topographies is evaluated. The coatings were prepared either from a fluoropolymer incorporated with nanoparticles or by etching aluminum alloy substrate followed by further hydrophobization of the rough surface via an organosilane monolayer adsorbed from solution. This allowed comparing the ice-releasing performance of rough surfaces with high water contact angles (∼ 150-153°) and different dynamic hydrophobicities and mechanical properties. Artificially created glaze ice, similar to naturally occurring glaze, was accreted on the surfaces by spraying supercooled water microdroplets in a wind tunnel at subzero temperature. The ice adhesion strength was evaluated by spinning the samples in a centrifuge at constantly increasing speeds until ice detachment occurred. The results showed that, after several icing-deicing cycles, the more robust surfaces prepared by etching the aluminum substrate maintained their ice-releasing properties better, compared to their counterparts based on nanoparticle-incorporated fluoropolymer. The effect of the dynamic hydrophobicity of the coatings was also examined, clearly demonstrating that the surface with low dynamic hydrophobicity is not ice-repellent, although it demonstrates large values of water contact angle.