硅藻土/TiO2基超疏水涂层的制备及应用研究

以硅藻土和TiO₂为微纳米结构的构筑物，以聚二甲基硅氧烷为低表面能改性剂，采用喷涂法在多种基底表面制备超疏水涂层材料。该涂层具有优异的超疏水性能，水静态接触角高达161°,表面自清洁性能优异，且耐热温度可高达350℃。该超疏水涂层材料在纺织品自清洁、医用防水及工业防腐等领域具有一定的应用前景。     

纳米SiO2@超支化PDMS复合超疏水涂层的制备与性能调控

超疏水涂层在实际应用中受化学腐蚀、刮擦磨损等外界环境的影响,易造成涂层老化、开裂甚至脱落,造成涂层失效。因此,针对这一问题,设计出具备耐候性的自修复超疏水表面：以超支化聚二甲基硅氧烷为柔性基底和低表面能物质,引入纳米二氧化硅构筑表面粗糙结构,制备超疏水涂层。当SiO₂粒径为50 nm、固含量为30wt%时,得到了接触角为154.87°的超疏水涂层。经过5次胶带剥离试验,涂层表现出良好的机械稳定性。经历10次温差循环试验和24 h紫外光照射后,涂层表面接触角仍大于150°,表明涂层具有良好的耐候性。涂层经过80℃、2 h的热处理可修复划痕,表明该涂层具有一定的自修复功能。同时,Tafel及Nyquist测试结果表明,对基底进行超疏水处理可显著提高防腐性能,并且该涂层具有明显的自清洁效果。综上所述,本文所制备的纳米SiO₂@超支化聚二甲基硅氧烷(PDMS)复合超疏水涂层具有自修复功能,为自修复超疏水涂层的开发提供了新的研究策略。     

巯基烯烃点击反应制备超疏水聚偏氟乙烯中空纤维膜及其加湿性能

为更好地发挥中空纤维膜加湿器的加湿作用,提高加湿性能,提出对中空纤维膜进行超疏水改性.利用溶胶凝胶法制备二氧化硅(SiO2),八乙烯基笼型倍半硅氧烷(OV-POSS)与巯基-聚二甲基硅氧烷(PDMS-SH)通过巯基烯烃点击反应形成POSS-S-PDMS聚合物,利用涂覆法将其涂覆在聚偏氟乙烯(PVDF)中空纤维膜表面.在膜表面与涂层、涂层与涂层之间均利用化学键连接以提高涂层的牢固度,制备了一种具有SiO2-PDMS-POSS稳定性涂层的超疏水复合膜.研究了光引发剂的质量分数、二氧化硅粒径影响因素对复合膜的影响,并对复合膜进行了表征.最终制备的复合膜接触角达到156°,加湿效率由48％提高为58.32％.     

Vi-PDMS/S-SiO2超疏水聚酯纤维织物的制备及性能研究

目的 基于普通织物材料防水性较差的问题,制备一种具有超疏水涂层的聚酯纤维织物,并对其性能进行研究。方法 以聚酯纤维织物为基材,基于紫外光固化技术通过浸涂法,使用商用气相纳米SiO₂颗粒(S-SiO₂)、端乙烯基聚二甲基硅氧烷(Vi-PDMS)在织物表面构筑微纳粗糙结构,获得超疏水的织物。采用扫描电子显微镜、水接触角测量仪对其微观结构和疏水性能进行表征,并通过机械摩擦实验对其超疏水稳定性进行考察。结果 当Vi-PDMS和S-SiO₂质量比为1∶4时,选择交联剂为三羟甲基丙烷三丙烯酸酯(TMPTA)制备的聚酯纤维织物表面的水接触角可达到151°,滚动角可达9°;且经过40次循环摩擦后,其表面水接触角仍大于140°,具有一定的耐磨性。结论 基于紫外光固化技术,采用操作简便的浸涂法制备的聚酯纤维织物具有优异的超疏水性能和一定的耐磨性,为织物超疏水性能研究提供参考,有望应用于超疏水聚酯纤维织物领域。     

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。     

PDMS/PTFE杂合固化制备自清洁超疏水涂层

以正硅酸乙酯(TEOS)为交联剂、二月桂酸二正辛基锡(DOTDL)为催化剂,利用聚二甲基硅氧烷(PDMS)与聚四氟乙烯(PTFE)超细粉杂合固化在玻璃基体上制得具有一定透明度的自清洁超疏水涂层。使用接触角测量仪、扫描电镜、傅里叶红外光谱仪对表面浸润性、形貌及结构进行表征,讨论了PTFE超细粉加入量对表面结构和浸润性的影响,探究了涂层的自清洁性能。制得的超疏水表面静态接触角最高达169.83°,滚动角2~3°,具有很好的超疏水性、低粘附力及自清洁性能。     

紫外光响应磁性超疏水木材的制备研究

为了将MnFe₂O₄晶体应用于超疏水木材，并研究其紫外光响应性，以乙酰丙酮铁和乙酰丙酮锰为反应原料，天冬氨酸为诱导剂，采用低温溶剂热法在木材表面沉积磁性MnFe₂O₄晶体，再将聚二甲基硅氧烷(PDMS)涂覆在木材表面，制备出磁性超疏水木材。采用傅里叶变换红外光谱仪、扫描电镜和X射线衍射仪对超疏水磁性木材进行分析表征，研究了反应温度和反应时间对木材表面疏水性的影响，并对超疏水木材的紫外光相应性和自清洁性能进行了研究。实验结果显示，木材的接触角随着反应时间和反应温度的升高先增大后减小，当锰铁比例为1∶1,溶剂热反应时间9h,反应温度90℃时，木材的接触角可达到154.34°。磁性超疏水木材在紫外光的照射下从超疏水变为亲水状态。此外，磁性超疏水木材具有良好的自清洁性能。     

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。     

基于聚二甲基硅氧烷和纳米CaCO_3的超疏水自清洁涂层的制备

利用聚二甲基硅氧烷(PDMS)与纳米CaCO_3,采用有机无机共混法制备有机无机复合涂层。向PDMS中引入适量的纳米CaCO_3粒子能显著提高复合涂层的表面接触角,纳米CaCO_3粒子的引入将PDMS涂层的表面接触角从113°提高到158°。该复合涂层具有非常好的自清洁性能。此外,该方法操作简单、步骤简便、无需特殊设备、适合大面积制备且生产成本低。因此,该超疏水自清洁涂层具有实用价值。     

Zinc oxide nanowire enhanced multifunctional coatings for cotton fabrics

Zinc oxide (ZnO) nanowires have been grown on cotton fabric to impart self-cleaning, superhydrophobicity and ultraviolet (UV) blocking properties. ZnO nanowires were grown by the microwave assisted hydrothermal method and subsequently functionalized with steraic acid to obtain a water contact angle of 150°, showing their superhydrophobic nature which is found to be stable up to 4 washings. UV protection of the resulting cotton fabric was also examined and significant decrease in the transmission of UV range was observed. Self-cleaning activity of the ZnO nanowire coated cotton fabric was also studied and it showed considerable degradation of methylene blue under UV light irradiation. These results suggest that ZnO nanowires could form ideal multifunctional coatings for textiles.     

Facile preparation and property analyses of L-CNC/SiO2-based composite superhydrophobic coating

In recent years, superhydrophobic coatings have received extensive attention due to their functions of waterproof, antifouling, self-cleaning, etc. However, wide applications of superhydrophobic coatings are still affected by their disadvantages of complex preparation, low mechanical properties, and poor ultraviolet (UV) resistance. In this study, cellulose nanocrystal containing a small amount of lignin (L-CNC)/SiO₂ composite particles were used as the main material, polydimethylsiloxane (PDMS) as the adhesive and perfluorooctyltrichlorosilane (FOTS) as the modifier to prepare superhydrophobic coatings by a one-step spray method. The resulted coating showed excellent superhydrophobicity (water contact angle (WCA) of 161° and slide angle (SA) of 7°) and high abrasion resistance (capable of withstanding 50 abrasion cycles under the load of 50 g). Moreover, it still maintained good superhydrophobicity after 5 h of exposure to the UV light (1000 W), displaying its good UV resistance. This study provides theoretical and technical reference for the simple preparation of organic‒inorganic composite superhydrophobic coatings with high abrasion resistance and good UV resistance, which is beneficial to improving the practicability and broadening the application scope of superhydrophobic coatings.     

Quenching of photocatalytic activity and enhancement of photostability of ZnO particles by polydimethysiloxane coating

ZnO particles with a size range of 50–150 nm were coated with polydimethylsiloxane (PDMS) with a thin film thickness of 3–4 nm using a simple ambient-pressure chemical vapor deposition method. Surfaces consisting of the PDMS-coated ZnO nanoparticles were found to be superhydrophobic with a water contact angle >160°. The superhydrophobicity was sustained in the presence of UV light. Photocatalytic activity and photocorrosion of ZnO were nearly completely quenched in the presence of PDMS-coating. It is suggested that our PDMS-coating can be of potential interest for the application of ZnO in UV protection agents and energy and electronic devices.     

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.     

喷涂法一步制备绿色超疏水白卡纸

目的 为改变纸张表面与水之间的相互作用,提高纸包装材料的抗水性,扩大纸包装的应用范围.方法 采用 γ-氨丙基三乙氧基硅烷(KH550)和聚二甲基硅氧烷(PDMS)对纳米二氧化硅进行疏水改性,然后将改性后的纳米二氧化硅喷涂在白卡纸表面.采用扫描电镜和X射线能谱对喷涂处理后白卡纸的表面形貌和元素组成进行分析,并对其性能进行考察.结果 喷涂后的白卡纸表面具有微纳粗糙结构,表面接触角为156.3°,滚动角为3.5°,具备了超疏水性能.制备的超疏水白卡纸具有优良的自清洁、防污、耐酸碱、耐高低温和牢固度等性能.结论 制备的超疏水白卡纸可用于多种包装场景,大大扩展了白卡纸的应用范围,并且制备过程操作简单,易于实现工业化.     

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。     

Robust Flower‐Like TiO2@Cotton Fabrics with Special Wettability for Effective Self‐Cleaning and Versatile Oil/Water Separation

Inspired by the hierarchical structure of the mastoid on the micrometer and nanometer scale and the waxy crystals of the mastoid on natural lotus surfaces, a facile one‐step hydrothermal strategy is developed to coat flower‐like hierarchical TiO₂ micro/nanoparticles onto cotton fabric substrates (TiO₂@Cotton). Furthermore, robust superhydrophobic TiO₂@Cotton surfaces are constructed by the combination of hierarchical structure creation and low surface energy material modification, which allows versatility for self‐cleaning, laundering durability, and oil/water separation. Compared with hydrophobic cotton fabric, the TiO₂@Cotton exhibits a superior antiwetting and self‐cleaning property with a contact angle (CA) lager than 160° and a sliding angle lower than 5°. The superhydrophobic TiO₂@Cotton shows excellent laundering durability against mechanical abrasion without an apparent reduction of the water contact angle. Moreover, the micro/nanoscale hierarchical structured cotton fabrics with special wettability are demonstrated to selectively collect oil from oil/water mixtures efficiently under various conditions (e.g., floating oil layer or underwater oil droplet or even oil/water mixtures). In addition, it is expected that this facile strategy can be widely used to construct multifunctional fabrics with excellent self‐cleaning, laundering durability, and oil/water separation. The work would also be helpful to design and develop new underwater superoleophobic/superoleophilic materials and microfluidic management devices.     

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.