乙醇辅助激光一步法制备硬质合金疏水表面

目的 在YT15硬质合金刀片上制备出具有疏水特性的织构表面.方法 在静态的无水乙醇环境中,利用光纤激光打标机,在YT15硬质合金刀片上制备织构,制备好的织构表面不做任何改性处理.根据织构表面形貌、织构表面化学成分,分析加工环境及激光参数对织构表面润湿性的影响.结果 无水乙醇辅助激光制备的织构表面表现出了疏水特性,疏水角...     

One-step process to deposit a soft super-hydrophobic film by filamentary dielectric barrier discharge-assisted CVD using HMCTSO as a precursor

In this study, a relatively simple process is used to deposit a soft super-hydrophobic film using hexamethylcyclotrisiloxane as a precursor by dielectric barrier discharge-assisted chemical vapor deposition. The purpose of this study is to introduce a phenomenon of the creation of a double rough structure on a substrate. A maximum contact angle of approximately 162° was obtained and the film grew in the shape of a double roughness structure, similar to a lotus leaf, indicating a super-hydrophobic surface. The results of the aging test indicated that the as-grown super-hydrophobic surface was stable against moisture and was only dependent on the growing structure of films.     

激光织构化不同材料表面对润湿性能的影响

采用激光微织构加工技术分别在SAF2507双相不锈钢和碳纤维增强聚醚醚酮(CF/PEEK)表面制备不同形状、面积占有率的微织构凹坑，通过润湿性试验分析时间、液滴体积、微织构形状与面积占有率、液滴种类对润湿性的影响。结果表明：液滴润湿材料表面过程中，固液接触角先随时间迅速减小，后保持在一个较为稳定的值；使用体积较大的液滴测量接触角时，液滴铺展的速度减缓，接触角的测量值变小；CF/PEEK表面的接触角随微织构面积占有率的增大而减小，SAF2507表面的接触角随微织构面积占有率的增大而增大；微织构面积占有率相同的表面，方柱形微织构表面的接触角小于圆柱形微织构表面，润湿效果更好；天然海水在光滑和织构表面的接触角均小于蒸馏水。     

超疏水涂层的制备及其性能

通过在有机硅改性丙烯酸树脂中加入具有疏水作用的纳米及微米级颗粒,在碳钢表面制备超疏水涂层。利用扫描电镜和接触角测定仪对涂层表面的微观结构及疏水性能进行表征,结果表明：该涂层结构与荷叶表面的微观结构很相似,水滴与涂层表面的接触角达到了150°,涂层具有超疏水性能。     

Superhydrophobic electrosprayed PTFE

This paper shows the deposition of superhydrophobic PTFE (polytetrafluoroethylene) films on FTO (fluorine doped tin oxide) coated glass slides, employing the electrospray technique, using a commercial PTFE particle suspension in water. Water contact angles as high as 167° were measured on the PTFE surface. Water drop sliding angles at 2° show a very low contact angle hysteresis. Scanning electron and atomic force microscopy images show the typical rough micro/nanostructure required for superhydrophobicity.     

绿色环保型超疏水涂层的研究进展

针对近期发表的绿色环保型超疏水涂层相关研究进行总结，从绿色环保型超疏水涂层的制备方法、研究进展和应用领域3个方面进行了综述。介绍了现阶段绿色环保超疏水涂层的制备原理和制备方法，简要概述了通过涂覆法、模板法、刻蚀法、静电纺丝法等制备方法的代表性应用研究，并分析了各自的优点以及目前存在的问题。着重介绍了天然蜡类、脂肪酸类、纤维素类和生物质类绿色环保型超疏水涂层的相关最新进展和制备方法，对不同种类的环保疏水涂层的优劣势进行了详细的分析。最后，对目前绿色环保超疏水涂层在自清洁、防腐以及油水分离涂层领域的应用进行了总结，针对目前绿色环保型超疏水涂层应用中所存在的问题提出了进一步研究的建议，并对未来的发展趋势进行了展望。     

基于激光加工和自组装技术改性处理铝镁合金的表面润湿性

为制备具有更高机械强度和更长使用寿命的超疏水金属表面,利用激光加工技术在铝镁合金表面构建出圆台凸起、圆台凹坑和正四棱台3种微结构。利用自组装技术在具有以上3种微结构的铝镁合金表面沉积自组装分子膜(SAMs),采用扫描电镜、形貌分析仪和接触角测量仪对成膜后的铝镁合金表面进行形貌和接触角的表征与测量。结果表明:沉积疏水的FDTS和OTS自组装分子膜时,接触角随微结构间距的增大而减小,随微结构高度的增大而增大,最大接触角达156°,形成超疏水铝镁合金表面;沉积亲水的APS自组装分子膜时,接触角随微结构间距的增大而增大,随微结构高度的增大而减小,最小接触角接近0°,形成超亲水铝镁合金表面;激光加工和自组装技术可以大幅度改变铝镁合金的表面润湿性。     

Pb-Ca-Sn合金的变形与再结晶组织、微观结构和动力学

在室温下将Pb-0.08Ca-2Sn合金轧制到不同厚度。电阻率和显微硬度的测试结果表明,样品在80~120°C的温度区间退火时发生再结晶。XRD检测确定变形组织为Brass型,所测得的Lankford各向异性参数R及其变化与用自洽方法所推导的结果接近。R值随轧制方向角度的改变表明该合金具有平面各项异性和较差的延展性。合金在80~120°C的温度范围内退火时,在3×104s内完成再结晶,显示出保留变形组织并有新Cube组元出现。     

金属表面疏水性研究进展

表面疏水性是近年来科学研究的热点。在生活中观察到荷叶表面上的水滴呈现圆球状,并能在荷叶上滚动而带走灰尘。研究发现荷叶表面具有优越的疏水性和自清洁特性,主要是由其表面微观的粗糙结构和低表面能物质共同引起的。概述了荷叶表面疏水性产生的原因,指出由于荷叶表面存在大量的微米级乳突,在这些微米级乳突上还有一些纳米级结构,这种纳米级结构正是引起荷叶表面超疏水的根本原因。归纳了疏水性表面的重要理论,其中,Young方程针对平整、光滑表面,将液滴在光滑表面上的张力和接触角联系起来;Wenzel模型是在Young方程的基础上引入了粗糙度因子,Wenzel模型中液滴形成的是一种非复合式的润湿状态,液滴和固体表面完全接触;Cassie方程是Wenzel模型的延伸,液滴和固体之间不再是单纯的非复合式接触,而是混有一定空气的复合式接触。在此基础上,综述了近年来表面疏水性的制备方法,包括化学法、特种加工法和微切削法等,最后展望了疏水性表面目前存在的问题。     

A parametric study of Inconel 625 wire laser deposition

Laser deposition with wire offers saving potentials over powder based systems. These include a cleaner processing environment, reduced economic and environmental cost of producing the wire, better surface finish and higher material deposition rates. This technique is rapidly finding applications for the manufacture and repair of high value components. For the first time, the deposition of Inconel 625 wire for single tracks at varying processing parameters using a 2-kW Ytterbium doped fibre laser has been investigated. A process map predicting the process characteristics in terms of wire dripping, smooth wire transfer and wire stubbing at different cladding conditions has been developed. Track geometrical characteristics including aspect ratio and contact angle were evaluated using surface profilometry and optical microscopy. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy was used to determine the dilution ratio (%) of the tracks. Wire deposition volume per unit length of track and energy per unit length of track were found to be key parameters influencing both the process and track geometrical characteristics. Aspect ratio and dilution ratio showed positive dependency whereas contact angle showed negative dependency on energy per unit length of track. Conversely, material deposition volume per unit length of track varied directly with contact angle but inversely with aspect ratio and dilution ratio (ranging from 0% to 24%). Processing conditions at which a combination of favourable single track properties including low contact angle (<80°), minimal dilution ratio (5–13%) and high surface quality were achieved are presented. These properties are required for depositing overlapped tracks of good surface finish, minimal dilution and free of inter-run porosity.     

微观凸织构及润湿性对橡胶滑动接触界面摩擦特性的影响EI北大核心CSCD

橡胶材料在日常生活和工业发展中有着广泛的应用,现有研究主要针对橡胶材料的黏弹特性、表面改性等方面展开,而固体表面微观织构对橡胶滑动接触界面摩擦特性的影响研究较少。针对橡胶滑动接触界面,在往复式摩擦试验机上以钢球和PDMS橡胶块组成摩擦副进行往复摩擦试验,通过改变织构类型和形貌参数来对不同表面形貌下的橡胶滑动摩擦特性进行相关探究,同时还考虑表面润湿性对界面摩擦因数的影响。试验研究表明:润滑状态下橡胶表面添加适当凸织构会降低滑动摩擦因数,微织构形状、面积占有率、高度和直径对橡胶表面滑动摩擦因数和接触角大小都有影响,尤其对于长槽织构,其摩擦因数和接触角大小呈现出方向性。结合摩擦因数和润湿性规律发现,一定范围内增大凸织构直径,橡胶表面润湿性变好,摩擦因数减小;增大凸织构面积占有率、高度时橡胶表面润湿性变差,摩擦因数反而减小。研究橡胶表面微观凸织构及其诱发的润湿性变化对橡胶滑动接触界面摩擦特性的影响,可为橡胶材料表面的摩擦学设计提供理论基础。     

Superhydrophobicity from composite nano/microstructures: Carbon fabrics coated with silica nanoparticles

This study demonstrates the hydrophobic coating of silica nanoparticles onto microscaled carbon fabrics (CFs) and investigates the superhydrophobic behavior of composite nano/microstructures. The two-tier composite surfaces are based on regularly ordered carbon fibers (8-10 µm in diameter) that are coated with SiO₂ nanoparticles with an average size of 300-500 nm. The microscale fiber is used here as the primary surface roughness, while the silica nanoparticles serve as the secondary roughness, mimicking the lotus leaf in nature. Increasing the density of silica on CFs showed significant effects on the enhancement of static contact angle, decrease of contact angle hysteresis, and superhydrophobic stability. The results can be attributed to the fact that the higher density of silica coating results in more tortuous three-phase contact line, thus facilitating the self-cleaning effect.     

Preparation and characterization of superhydrophobic silica-based surfaces by using polypropylene glycol and tetraethoxysilane precursors

Preparation of superhydrophobic silica-based surfaces via sol-gel process by adding polypropylene glycol (PPG) polymer into the precursor solution has been developed. Surface roughness of the films was obtained by removing the organic polymer at 500 °C and then the hydrophobic groups bonded onto the films were obtained by chemical reaction with hexamethyldisilazane (HMDS). Physical properties of the as-prepared films were analyzed by contact angle measurements, scanning electron microscopy (SEM), UV-VIS scanning spectrophotometer and Fourier transform infrared (FT-IR) spectrophotometer. The experimental parameters were varied by the type of silane species, the weight ratio of PPG solution to precursor solution, the hydrolysis time of the precursor solution, the molecular weight of PPG, the casting temperature and the evaporation temperature. The phase separation of the PPG polymer rich domain occurred on the substrates at a lower temperature. The result showed that the contact angles of the films prepared at 5 °C were greater than 150° when the weight ratio of PPG solution to precursor solution was 5. In addition, the transmittance of the films was greater than 80% simultaneously.     

叶片表面微细观结构对润湿性的影响

目的 探究叶片表面微细观结构对其润湿性的影响因素,以及控制机理。方法 以银杏（Ginkgo biloba,G. biloba）、二乔玉兰（Magnolia soulangeana, M. soulangeana）和二球悬铃木（Platanus acerifolia, P. acerifolia）3种处于落叶期初段的叶片样本为研究对象,测量3种叶片正背面的接触角,结合环境扫描电子显微镜图像,对比分析不同叶片正面和背面微细观结构及其对接触角的影响。结果 实验结果表明,落叶期初段银杏、二乔玉兰和二球悬铃木叶片正面均表现出弱亲水性,接触角分别为54.40°～66.80°、57.93°～74.87°、55.73°～82.23°。在银杏叶片背面,无论是顺纹理还是逆纹理方向,均表现出疏水特征,顺纹理方向的接触角为122.63°～135.10°,逆纹理方向的接触角为103.03°～134.13°。二乔玉兰和二球悬铃木的背面为中性润湿,接触角分别为82.87°～96.37°、90.50°～97.47°。结论 不同类型叶片的表面微结构显著不同,同种类型叶片正背面微结构也表现出较大差异。3种叶片背面接触角均...     

Super-hydrophobic surface treatment as corrosion protection for aluminum in seawater

“Underwater super-hydrophobic” surface applied in the corrosion protection was prepared by melting myristic acid (CH₃(CH₂)₁₂COOH) adsorbed onto the anodized aluminum. The static contact angle for seawater on the surface was measured to be 154°. The surface structure and composition were then characterized by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDS) and atomic force microscope (AFM). The electrochemical measurements showed that the super-hydrophobic surface significantly improved the corrosion resistance of aluminum in sterile seawater. In addition, the mechanism of the underwater super-hydrophobic surface applied in the corrosion resistance was discussed using a schematic.     

掩膜电解微坑阵列对钛合金表面疏水性能的影响

为了提高钛合金表面的疏水性能,采用润湿理论模型与多物理场耦合仿真相结合的方法,建立接触角与掩膜电解加工工艺参数之间的直接映射关系,揭示微坑阵列掩膜电解加工对表面疏水性能的作用。建立接触角与微坑阵列几何尺寸间的表面疏水理论模型,对掩膜电解加工进行多物理场耦合仿真;理论模型与仿真结果相结合,获得了接触角与掩膜电解加工工艺参数之间的直接映射关系。此外,以表面接触角为因变量,以电解质质量分数、掩膜尺寸和电解电压为自变量,进行正交试验仿真和计算,获得了最佳工艺参数组合并进行试验验证。与仿真计算相比,试验测量得到的微坑阵列直径、间距、深度、表面接触角误差分别为2.49%、6.87%、7.40%、6.01%,从而表明该方法在未经低表面能材料修饰的情况下,成功制备接触角约为141°的微坑阵列疏水表面。     

表面织构对不锈钢-衬垫副摩擦磨损特性的影响

为研究织构及其形状对G95Cr18不锈钢与自润滑衬垫摩擦副摩擦磨损特性的影响,采用紫外皮秒激光器在G95Cr18不锈钢销表面制备了不同形状的织构.采用扫描电子显微镜、3D共聚焦显微镜和接触角检测仪观察了织构形状和表面润湿角的变化,采用旋转式销盘接触摩擦磨损试验机检测了 G95Cr18不锈钢-自润滑衬垫摩擦副的摩擦磨损特...     

Carbon tetrafluoride plasma modification of polyimide: A method of in-situ formed hydrophilic and hydrophobic surfaces

This study demonstrates that carbon tetrafluoride (CF₄) plasma can result in relatively hydrophobic and hydrophilic surfaces formed in-situ on polyimide (PI) films using a mask and controlling the distance of the mask to the substrate. The surface properties of plasma-treated PI films are characterized by contact angle measurement, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Under specific modification conditions, contact angles for hydrophobic and hydrophilic surfaces reach values of 108.3 ± 0.6° and below 5°, respectively. The XPS analyses indicate that the “unshielded” surfaces contained a high proportion of the CF₂-CF₂ group and therefore decreased the wettability of the surface. On the other hand, the “shielded” surface contained hydrophilic groups such as carbonyl or carboxyl with few fluorinated groups, resulting in increased wettability of the surface.     

Fabrication of superhydrophobic Cu surfaces with tunable regular micro and random nano-scale structures by hybrid laser texture and chemical etching

Hydrophobic Cu surfaces with tunable regular microstructure and random nanostructures were fabricated by nanosecond pulsed laser texturing and chemical etching. The regular micro-scale roughness can be tuned from 5 μm to 30 μm Rz by nanosecond laser texturing while the ligament width and spacing of the random nano porosity about 10-50 nm can be realized by selective chemical etching. Wettability tests demonstrate that the Cu surface with this micro/nanostructural hierarchy, analogous to that of lotus leaves found in nature, is superhydrophobic with a water contact angle around 153°. The random nanostructure by selective etching plays an important role for hydrophobicity in addition to the regular microstructure by nanosecond laser texturing.     

采油液力马达转子表面织构参数对其摩擦副摩擦学性能的影响

目的研究微沟槽织构对采油液力马达定转子配副表面摩擦学性能的影响,为减小液力马达螺旋副的摩擦阻力矩,从而解决大庆油田某型号液力驱动螺杆泵采油系统停机后启动困难的问题提供设计方向。方法根据螺杆马达螺旋副,建立金属-橡胶平板往复摩擦模型,在金属试件表面加工出不同织构角度和深度的矩形微沟槽,采用正交试验方法,研究不同织构参数对液力马达螺旋副摩擦性能的影响规律,最后再对比分析橡胶试件摩擦磨损试验前后的表面形貌,以掌握织构存在对橡胶定子使用寿命的影响规律。结果织构角度一定时,除90-5号试件以外,其余各组试件的摩擦因数表现出随织构深度的增加而增加的现象。织构深度一定时,各组试件的摩擦因数随织构角度的增大而表现出先增大后减小的现象。织构角度是摩擦因数的主要影响因素。相同试验条件下,0—5号试件的摩擦因数比未织构试件降低了20.2%。结论在液力马达定转子这种金属-橡胶接触对中,织构的减摩机理主要是通过微沟槽输送润滑介质,改善润滑条件。织构参数设计合理的试样,在不缩减液力马达使用寿命的条件下可以有效减小摩擦副的摩擦因数,有利于液力驱动螺杆泵采油系统顺利启动。