基于纤维素纳米纤维的超疏水涂层制备研究

采用简单的浸涂法制备具有优异自清洁性能和良好耐久性能的超疏水涂层。基于纤维素纳米纤维(CNF)与低表面能物质聚二甲基硅氧烷(PDMS),以棉织物为基底制备了超疏水涂层,实现了棉织物表面功能化。通过单因素实验分别研究不同浓度CNF以及不同浓度PDMS对涂层疏水性的影响,并采用红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TGA)等对超疏水涂层进行了测试表征。CNF和PDMS在棉织物表面牢固结合,成功制备了耐久超疏水涂层。SEM结果显示,与纯PDMS涂层相比,CNF构筑了超疏水涂层所需的微观粗糙结构,为超疏水涂层的制备提供了有利条件。当PDMS浓度为4%,CNF浓度为4%时,超疏水涂层的水滴接触角(WCA)达159.2°,水滴滚动角(WSA)为4.3°。耐摩擦测试结果显示,经过40次砂纸摩擦之后涂层的水滴接触角仍达150.3°,具有超疏水性能,说明PDMS为涂层提供低表面能的同时,也具有良好的粘结性能进而提高了涂层的耐久性能。采用CNF和PDMS在棉织物表面成功制备了耐久超疏水涂层,同时实现了优异的自清洁、防水抗污性能,并且具有良好的耐久性能。     

离子交换可逆调控棉纤织物表面超疏油性能

采用自组装聚电解质多层膜和离子交换法调控基体表面的疏油性能。在光滑的玻璃表面上可以控制十六烷的接触角在69°和4°之间变化。在棉纤织物上,当聚电解质多层膜吸附全氟辛酸根离子时,织物表面是超疏水和超疏油的,与水的接触角达到154°,与十六烷的接触角高达150°。当全氟辛酸根离子被十二烷基硫酸根离子替代后,水的接触角没有明显的变化,在152°左右,而十六烷却能完全浸润表面,接触角为0°。通过全氟辛酸根离子和十二烷基硫酸根离子的交换,织物表面可以在超疏油和超亲油之间可逆转换,这对于拓展超疏油表面的应用都具有重要的意义。     

近红外反射超疏水黄色涂层的制备和性能

将钛铬棕粉末(TCB)、金红石型二氧化钛(TiO₂)、疏水纳米二氧化硅(SiO₂)与聚二甲基硅氧烷(PDMS)溶液混合,一步刷涂制备出超疏水黄色涂层,系统地研究了涂层的表面润湿性、疏水稳定性、耐紫外线老化性能、自清洁性能、以及近红外反射性能。结果表明,这种涂层的水接触角(CA)和滚动角(SA)分别为155.2°和5.4°;涂层在1.0 kPa的压力下经过2 m距离的砂纸磨损后和5 L的水流冲击后依然保持优异的疏水性,其附着力和硬度分别达到2级和6B等级;不同pH值的溶液在涂层表面都具有超疏水效果并具有化学稳定性;用紫外线照射240 h后涂层表面仍然保持极强的疏水性,表明其具有耐紫外线老化性能;涂层表面具有优异的自清洁性能,污染物极易地被水滴带走;涂层的近红外反射率和太阳反射率分别达到0.858和0.672,对普通水泥板具有明显的降温效果,在户外暴露和水流冲击后仍保持较高的反射率。     

透明超疏水疏油涂层的制备及性能

以纳米SiO2和聚合物为原料,采用喷涂的方法,在不同基材的复杂工件表面形成均一涂层,并研究了SiO2含量对涂层性能的影响。结果表明,所得涂层与水接触角>150°,与油的接触角超过90°,具有超疏水性和疏油性。此外,涂层具有很好的透明性,涂层硬度高达6H,附着力达到5B。适当添加纳米SiO2,涂层的疏水性、疏油性以及透过率均得到增强。     

耐腐蚀耐热超疏水TiO_2复合涂层制备与性能研究

铝基板表面的超疏水特性将赋予其优异的性能。利用环氧树脂(E44)和改性聚偏氟乙烯(PVDF)的作用,以改性纳米级二氧化钛(TiO_2)和全氟乙烯丙烯共聚物(FEP)疏水低表面能物质为主要填料用简单易行的喷涂工艺制备出功能超疏水涂层。实验结果表明,制得的超疏水涂层,对水的静态接触角和滚动角分别为151°和5°;采用扫描电镜(SEM)表征了涂层表面有纳微二元复合微观结构;用差示扫描量热法(DSC)表征表明,该涂层在160℃下有优良的耐热性能;用不同pH值溶液进行浸没腐蚀以及电化学测其耐腐蚀性,腐蚀时间为180h时接触角仍有130°左右,具备强疏水效果。这种超疏水涂层为腐蚀耐热材料领域的研究提供了新的视野。     

超疏水硅橡胶涂层的制备

采用相分离的方法制备了超疏水硅橡胶涂层,并研究了配比、温度、时间和溶剂对涂层疏水性能的影响。采用接触角测试仪对涂层和粉末的疏水性进行了测试,用扫描电镜(SEM)进行了形貌表征。结果表明:在一定的条件下,接触角最高可达155.14°;即使涂层变成粉末,仍然具有非常好的疏水性;SEM测试表明材料是多孔的,并且表面有大量的微纳突起结构。     

碳纤维颗粒增强CeO2/PMMA/PVDF超疏水复合涂层及其耐磨性能

提高耐磨性能是推动仿生超疏水表面走向实际应用的关键挑战之一。设计了二氧化铈微米粒子增强PMMA/PVDF超疏水复合涂层配方,获得了水珠接触角达152°、水珠滚动角为5°的超疏水复合涂层。该涂层经过落砂磨损试验后接触角下降为103°、滚动角增大为20°。采用碳纤维颗粒对CeO2/PMMA/PVDF超疏水复合涂层进行增强,优化配方的接触角达153°、滚动角达到5°。经过相同落砂磨损试验后,增强后的复合涂层水珠接触角能在一定程度磨损后达到140°左右。可见,CeO2/PMMA/PVDF复合涂层具有良好的超疏水性能,碳纤维颗粒增强是提高该涂层耐磨性能的有效方法。     

两步法制备黄铜表面超疏水肉豆蔻酸/TiO2涂层与性能研究

采用化学刻蚀法和复合改性两步法在黄铜基体上制备了超疏水肉豆蔻酸(MA)/TiO₂涂层(E-MAT)。通过接触角测量仪详细考察了刻蚀时间与刻蚀温度对黄铜疏水性能(刻蚀并改性后)的影响。结果表明,当刻蚀时间为55 min,刻蚀温度为30℃时,且经MA/TiO₂复合改性的黄铜表面可获得高达167.4°的水接触角。接着,采用SEM、CLSM、EDS、XRD与FTIR对E-MAT涂层进行了形貌与成分分析。分别利用砂纸磨损与胶带剥离实验研究E-MAT涂层的机械稳定性。此外,E-MAT超疏水涂层还表现出优异的自清洁性能。在3.5%NaCl溶液中的电化学腐蚀测试显示E-MAT涂层自腐蚀电流密度下降至8.32×10^-5 A/cm²,腐蚀保护效率高达97.0%。可见,刻蚀-改性结合法操作简单,便于构造大面积金属基超疏水表面,具有广阔的应用前景。     

SiO2/凹凸棒土复合材料自修复超疏水涂层的制备与性能

在过去的几十年中,超疏水表面由于其特殊的性能而受到极为广泛的关注,但是在室外应用中,受环境中各种因素的影响,大多数超疏水表面很轻易会失去其超疏水性。采用简单的两步浸涂法制备得到一种表面坚固的可修复超疏水涂层。以聚硅氧烷与无水乙醇混合制得涂层底层;中性硅酮玻璃胶、纳米SiO2、微米级凹凸棒土(ATP)粉末以及聚硅氧烷共混制得涂层面层。利用扫描电子显微镜(SEM)、接触角测量仪、傅里叶变换红外光谱仪(FTIR)对涂层的微观形貌、润湿性、分子结构进行表征。确定了中性硅酮玻璃胶的最佳用量,考察了涂层的耐磨性能、自清洁性能以及机械磨损与酸碱环境下的自修复性能。结果表明：中性硅酮玻璃胶添加量在质量分数为1wt%时涂层疏水能力最佳,水接触角达到153.5°±1.5°。在50 g砝码(1.03 kPa)下经过360 cm的机械磨损,涂层仍具备140°以上的水接触角。并且涂层在受到一定程度的机械磨损或是酸碱破坏后,都可以通过高温加热实现涂层超疏水性能的修复,此外涂层还具备一定的耐水稳定性以及优异的自清洁能力。     

超疏水环氧树脂复合材料的制备

使用简单的高压喷射法,在环氧树脂复合材料基底上制备出了超疏水表面。通过扫描电子显微镜和接触角测试仪对超疏水环氧树脂复合材料表面的形貌和润湿性能进行表征和分析。研究结果表明:制备的PDMS/纳米SiO_2涂料中纳米SiO_2与液体PDMS重量比为4:13时,涂层表面超疏水性能较佳,涂层与水的接触角达到156±2°。     

轮胎模具DLC涂层的制备及性能

为探究高性能轮胎模具类金刚石(DLC)涂层的应用前景,提高模具花纹块内表面的疏水性及耐磨减摩性,采用等离子体增强化学气相沉积法在35钢基体上制备DLC涂层,并对所制备的DLC涂层的表面形貌、粗糙度、疏水性、表面元素组成、纳米硬度、摩擦系数等关键指标进行了测定.结果表明:DLC涂层具有优良的表面完整性,水接触角可达19.62°,乙醇接触角达20.37°,纳米硬度可达19.62 GPa,摩擦系数低至0.405 8,DLC涂层有望替代Teflon涂层,用于高性能轮胎模具.     

Preparation of microstructure-controllable superhydrophobic polytetrafluoroethylene porous thin film by vacuum thermal-evaporation

The three-dimensional porous network polytetrafluoroethylene (PTFE) thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologies by adjusting the evaporation temperature and the corresponding contact angle ranging from 133° to 155°. Further analyses of surface chemical composition and morphology by FTIR and FE-SEM revealed that the origin of hydrophobicity for the PTFE thin films could be ascribed to the fluorine-containing groups and the surface morphologies, indicating that abundant -CF₂ groups and network structures with appropriate pore sizes played a vital role in superhydrophobicity. By characterization of UV-Vis, the films also showed high transmittance and antireflection effect. The films prepared by this simple method have potential applications such as waterproof membrane and self-cleaning coating.     

Corrosion resistance and hydrophobicity of myristic acid modified Mg--Al LDH/Mg(OH)2 steam coating on magnesium alloy AZ31

A hydrophobic surface was successfully fabricated on the Mg–Al-layered double hydroxide (Mg–Al LDH)/Mg(OH)₂-coated AZ31 magnesium alloy via an in-situ steam coating (SC) process and a subsequent surface modification with environment-friendly myristic acid (MA). The microstructure, composition and hydrophobicity of SC/MA composite coating were investigated by XRD, SEM, EDS, FTIR, and contact angle (CA) measurement. The corrosion behavior of the hybrid coating was evaluated by potentiodynamic polarization, EIS and hydrogen evolution test in 3.5 wt.% NaCl solution. The results showed that the LDH coating had nano-flake microstructure, which remained unchanged after modification with MA. The CA of the MA-modified coating surface reached up to 129°±3.5°, and the corrosion current density of SC/MA-2 coating decreased about three orders of the magnitude compared to that of the substrate. It is proven that the modified surface has an effective anti-corrosion effect on AZ31 alloy. The formation mechanism and the corrosion mechanism of the coating were also discussed.     

T8钢—聚有机硅氧烷仿生减粘降阻复合涂层的特性

研究了Ｔ８钢－聚有机硅氧烷仿生减粘降阻复合涂层的表面润湿性，磨料磨损性及土壤的减粘降组性能，与金属材料相比，仿生复合涂层的表面憎水性显著提高，水在其表面上的接触角达９２°；与４５钢相比，其磨料磨损的体积相对耐磨系数为６３％，降阻率达１５．２２％－－２２．２７％。     

Fabrication of superhydrophobic and oleophobic zinc coating on steel surface

In this work, a simple method, including electrodeposition and chemical modification, for fabrication of a superhydrophobic and oleophobic coating on steel substrate is reported. The surface morphology of this coating showed concave structure, and the contact angles of water and glycerol on this coating surface were about 153.57° and 149.32°, respectively. In addition, the water droplet was easy to roll on this coating surface, and the sliding angle was smaller than 10°. The contact angle of the water/ethanol droplet with different surface tension, from 56 to 36?mN?m^?1, was also >130° on this coating surface, indicating this as superhydrophobic and oleophobic coating surface with good lyophobicity. Moreover, this coating surface had excellent non-sticking property for the water droplet under a certain external pressure, self-cleaning property and long-term stability.     

Preparation of multi-functional fabric via silver/reduced graphene oxide coating with poly(diallyldimethylammonium chloride) modification

In order to obtain multi-functional textile, polyester (PET) fabric was modified with poly(diallyldimethylammonium chloride) (PDDA) followed by silver/reduced graphene oxide (Ag/RGO) coating through chemical reduction method. The Ag/RGO coated PET fabrics were systematically characterized by X-ray photoelectron spectroscopy, scanning electron microscope and X-ray diffraction. The deposit weight, electrical resistance, static voltage half-life period, heat generation and water contact angle tests of the fabrics with and without PDDA modification were evaluated. It is concluded that there are uniform and dense silver particles and reduced graphene oxide (RGO) sheets deposit on the surface of the PET fabric modified with PDDA. Compared with the coated fabric without PDDA modification, the Ag/RGO coated PET fabric modified with PDDA shows lower electrical resistance of 0.173 Ω/sq, excellent antistatic property with half-life period of 0.5 s, heat generation with temperature keeping to 69.6 °C at voltage of 4 V and hydrophobicity with a water contact angle of 140.1°. Furthermore, the PDDA modification improves adhesion between Ag/RGO coating and PET substrate. In addition, electromagnetic interference (EMI) shielding effectiveness (SE), absorption and reflection characteristics were determined by a vector network analyzer in 1 GHz–18 GHz X-band range. The results exhibit that Ag/RGO coated PET fabric possesses an excellent EMI SE ranging from 52 to 57 dB and could be used as lightweight and flexible electromagnetic absorption materials.     

溶液浓度和非溶剂比例对PVC膜形貌和疏水性能的影响

目的 研究溶液质量分数和非溶剂体积分数对PVC薄膜表面形貌和疏水性能的影响,以获得具有超疏水表面的PVC薄膜。方法 以四氢呋喃为良溶剂、乙醇为非溶剂,利用非溶剂诱导相分离的原理,采用旋涂法在玻璃基底上制备超疏水的聚氯乙烯（PVC）涂膜;通过对PVC样品的疏水性、表面形貌、结晶性能和热性能进行分析,探究溶液质量分数以及非溶剂的体积分数对PVC样品性能的影响。结果扫描电镜和接触角测试表明,添加一定体积分数的乙醇使得所制备的PVC样品形成了多孔膜层以及纳米级聚合物球粒,从而提高了PVC样品的疏水性。XRD测试结果表明,添加乙醇并不会改变PVC样品的无定形结构。结论 PVC溶液质量分数对所制备PVC样品的疏水性能和表面结构没有明显影响,乙醇体积分数为30%～40%时,可形成表面水接触角大于150°的超疏水表面。     

轮胎模具无氢DLC涂层的制备及表征

为探究轮胎模具类金刚石(DLC)涂层的应用前景,提高模具表面的硬度和疏水性,按照模具加工工艺制备35钢基体试样,利用电弧离子镀在基体上沉积无氢DLC涂层,对涂层粗糙度、三维表面形貌、断面结构、元素组成及含量、Raman光谱、纳米硬度和疏水性进行了分析.结果表明:通过改变粗糙度可以改善涂层的疏水性,涂层疏水性随粗糙度增大而显著增加,水接触角最高可达96°,且涂层硬度可达30.3 GPa.无氢DLC涂层可满足轮胎模具耐磨性和易清洁的使用要求,为制造高性能轮胎模具提供了一种可行的工艺选择.     

Water-Repellent Approaches for 3-D Printed Internal Passages

In this work, two different manufacturing approaches are presented that create water-repellency (hydrophobicity and super-hydrophobicity) for acrylonitrile butadiene styrene (ABS) structures. In particular, this is the first study to render three-dimensional (3-D) printed ABS surfaces with internal flow paths to be superhydrophobic. The first approach uses standard wet-based chemical processing for surface preparation after which a fluorocarbon layer is deposited by dip coating or with vapor deposition. This first approach creates hydrophobic surfaces with roll-off angles of less than 30°. In the second approach, the ABS structures are dip-coated with a commercial rubber coating solution and subsequently surface-modified by reactive ion etching (RIE) with fluorinated gases to render the samples superhydrophobic, with roll-off angles as low as 6°. In order to further enhance their water-repellency, the dip-coating rubber solution is mixed with polytetrafluoroethylene (PTFE) colloidal dispersions to form a nanocomposite layer prior to the RIE process. The PTFE particles induce surface roughness as well as hydrophobicity. The modified surfaces created by the two approaches are further characterized by scanning electron microscopy and water drainage performance. Water drainage (prevention of water retention) is especially important for high thermal efficiency of 3-D printed heat exchangers. However, water-repellency for ABS is also interesting for a broader range of applications that use this material.