非晶型超疏水和超亲水TiO2薄膜的制备与表征

通过溶胶-凝胶法, 以载玻片为基底制得非晶型纳米TiO₂薄膜, 用SEM、 XPS、 XRD和接触角测量仪研究了薄膜的微观形貌、 表面元素、 晶型结构及薄膜的疏水性, 用Wenzel、 Cassie 理论对纳米TiO₂薄膜的润湿性进行了理论分析。结果表明, 经紫外光照射16 h后, 薄膜表面由超疏水性变为超亲水性, 接触角接近0°。薄膜表面合适的粗糙度和低表面能材料表面修饰的协同作用使其表现出良好的超疏水性。     

仿生超疏水涂层材料研究新进展

介绍了有关固体表面润湿性模型和构建超疏水表面涂层常用的低表面能物质,结合粗糙表面的构建方法,阐述了有关超疏水表面涂层材料的最新研究进展,指出超疏水涂层材料研究中存在的问题,并对超疏水涂层材料在油品输送、生物传感器,微流控件和智能分离膜等领域的应用前景进行了展望.利用低表面能物质对粗糙结构表面进行修饰,将涂层表面粗糙化与低表面能物质修饰两种技术进行有机结合是构建超疏水表面涂层的有效途径.     

六边形纳米CuI及其超疏水性

采用一步液相反应法,在常温常压下,制得六边形纳米CuI.无需任何低表面能物质(硫醉或氟烷基)修饰,该样品就表现出超疏水性,接触角达到157°.最为重要的是样品的超疏水性很稳定,在空气中放置半年后,其接触角无明显变化,具有潜在的应用价值.     

电火花线切割制备超疏水多孔钛及其油水分离的应用

利用电火花线切割的方法制备具有双尺度结构的超疏水多孔钛表面,用于实现油水混合物的分离。以多孔钛为基材,通过电火花线切割的方法在表面加工出阵列微沟槽结构,该表面经过全氟癸基三乙氧基硅烷的低表面能修饰后,制得超疏水多孔钛表面。利用接触角测试仪和电子显微镜等手段对超疏水多孔钛表面进行润湿性测量和形貌特征的分析,利用油水分离器测试超疏水多孔钛的油水分离能力。制备的超疏水多孔钛表面的接触角为162.6°,滚动角为0.5°,表现出低的粘附性。在油水分离试验中,超疏水多孔钛对于不同的油水混合物的分离率超过98%,耐压性测试发现该表面具有较好的耐压性能。化学稳定性测试和耐腐蚀性测试表明,超疏水多孔钛比基材具有更好的化学稳定性和耐腐蚀性。     

甲基硅酸钠刻蚀聚多巴胺涂层构建超疏水木材及表征

利用聚多巴胺(PDA)涂层黏附和去质子化的特性,采用甲基硅酸钠(SMS)刻蚀PDA涂层,进一步采用十八烷基三甲氧基氯硅烷(OTS)对其进行低表面能处理制备了稳固型超疏水木材(Wood@PDA-SMS-OTS)。采用接触角(CA)测定仪、SEM、XPS分别对试样进行了表征。结果表明,水在Wood@PDA-SMS-OTS试样表面的静态CA最高为157.4°,滚动角(SA)为4.3°;SEM图像表明,SMS成功刻蚀了PDA涂层,同时水解生成疏水性的低聚或半聚的甲基硅氧烷覆盖在PDA涂层表面,形成了明显的微纳米粗糙结构;XPS分析表明,PDA在木材的表面形成均匀的涂层,SMS在刻蚀PDA涂层的同时,其水解生成的聚合物成功负载在PDA的表面,含长链结构的OTS接枝在木材的表面,使木材具有超疏水性能;超疏水木材表面经过24 h的水流冲刷、超声波震荡、酸碱腐蚀及有机溶剂等处理后,仍具有较强的超疏水稳固性。      

膜蒸馏用PDMS/PVDF中空纤维疏水膜的研制

膜表面的疏水化是减缓膜蒸馏过程中膜润湿问题的有效策略.采用表面涂覆-固化法,利用聚二甲基硅氧烷(PDMS)、交联剂甲基三乙氧基硅烷(MTES)和催化剂二月桂酸二丁基锡(DBTL)在膜表面的反应,形成致密的甲基嵌段PDMS-MTES疏水层,制备了PVDF/PDMS疏水复合膜.探究了PDMS/MTES/DBTL质量比、PDMS质量分数和涂覆时间等对复合膜结构与性能的影响.利用该方法,复合膜接触角达到130°,膜的疏水性和膜蒸馏过程中的抗润湿能力得到显著提升.该膜在360 min的表面活性剂溶液膜蒸馏实验中性能稳定,而未改性膜在30 min内即完全亲水化.     

水泥基超疏水材料自清洁技术研究进展

超疏水材料是一种新型智能仿生材料，具有优良的自清洁、抗凝冰、防腐等性能，已广泛应用于航天、建筑、电力等领域。但在公路交通领域尚处于探索研究阶段。水泥基超疏水材料自清洁技术源于自然界的“荷叶效应”，超疏水表面的微纳结构和低表面能降低了污染物与涂层的粘附力，赋予超疏水表面优异的自清洁性，为水泥基材料的主动防污技术提供了新思路。目前，水泥基超疏材料自清洁理论与技术尚不成熟，主要通过表面微纳米复合结构和低表面能化学物质协同制备水泥基超疏水材料，从而实现水泥基材料自清洁功能。水泥基超疏水材料的制备技术主要包括表面疏水改性和本体疏水改性两种。硅烷/硅氧烷类和硬脂酸等疏水材料因其环保、成本相对低廉，使用频率较高。水泥基表面超疏水涂层处理类型主要包括涂覆法、模板法、层层自组装法等。表面超疏水改性对水泥基材料力学强度的影响较小，而整体超疏水改性因内掺疏水材料，延缓水泥水化反应，降低了水泥基材料的力学强度。水泥基表面超疏水涂层因其施工简便、性价比高、能耗低，应用更为广泛。水泥基超疏水材料自清洁性能评价方法尚未统一，其中以模拟污染物收集法应用较为广泛。由于水泥基材料工程结构复杂，影响因素众多，从实际工程应用...     

超疏水固体表面的制备及其量化表征

超疏水表面是指对水的接触角θ超过150°且滚落角α低于2°的固体表面,用来解释超疏水现象的两种经典理论分别是Wenzel模型和Cassie模型.在表征表面超疏水性时,除常用的θ、α外,接触角滞后△θ、斜面上液滴滞留在材料表面上的最大半径Rc、两种状态转化时的临界压力△p以及液滴落下后能反弹的临界撞击速度Vc也是非常重要的参数.依据表面微细结构和低表面自由能是构成超疏水表面的两个重要条件,阐述了通过在疏水表面构建表面微细结构和用低表面能物质修饰粗糙表面这两种方法制备超疏水表面,并提出了今后研究中应该注意的一些问题.     

轮胎模具F-DLC涂层的制备及性能

为探究高性能轮胎模具F-DLC涂层的应用前景,提高轮胎模具内表面的疏水性、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F-DLC涂层.利用Raman光谱仪与原子力显微镜对其结构与表面形貌进行了表征;利用接触角测量仪测量涂层的疏水角;另外,利用端面摩擦磨损试验机对涂层摩擦磨损性能进行了研究.结果表明:涂层内应力小、表面平整、颗粒均匀;涂层疏水角为98.54°,疏水性好;在140℃的试验温度下,摩擦系数低至0.271;纳米硬度为15.85 GPa,弹性模量为110.5 GPa.F-DLC涂层优异的性能可以有效提高轮胎模具脱模、抗粘胶的工作性能,为制造高质量的轮胎模具提供了一种可行的方案.     

超疏水涂层的制备及其在金属防腐领域的应用研究进展

由于超疏水材料表面的特殊结构和高疏水性，当其应用在金属表面时，能有效阻止金属基材与腐蚀介质的接触，从而大幅度地提高金属材料的耐腐蚀性能及使用寿命。首先对固体表面浸润理论以及超疏水材料的基础理论进行阐述；然后，介绍了在金属材料表面制备超疏水涂层的常用工艺技术；最后，总结并讨论了超疏水表面涂层在钢、铝和镁等金属材料上的近期发展与应用状况。     

Adhesion and friction properties of micro/nano-engineered superhydrophobic/hydrophobic surfaces

Hydrophobic micro/nano-engineered surfaces (MNESs) with good adhesion and frictional performances were fabricated by the combination of aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) and octadecyltrichlorosilane (OTS) coating. The AIC of a-Si technique was used to produce silicon micro/nano-textured surfaces, while an OTS self-assembled monolayer was used to lower the surface energies of the textured surfaces. The wetting properties of the MNESs were studied using a video-based contact angle measurement system. The adhesion and friction properties of the MNESs were investigated using a TriboIndenter. This study shows that the adhesion and frictional performances of all MNESs are significantly improved compared to untreated silicon substrate surfaces, and the adhesion and frictional performances of the OTS-modified textured surfaces strongly correlate to their surface wetting property, i.e., the larger the water contact angle, the better the adhesion and frictional performances of the OTS-modified textured surfaces.     

具有“荷叶效应”的硅基仿生表面的制备及其微摩擦性能

用扫描电子显微镜(scanning electron microscope,SEM)观测了荷叶表面的双微观结构,即特征尺度在10μm左右的微米乳突和直径为50～100 nm的纳米蜡质晶体.提出了制备具有"荷叶效应"的硅基仿生表面的两种方法,一是将表面制有特征尺度为100 nm左右纳米结构的硅片进行硅烷化疏水处理,仅制作了纳米结构,部分模拟了"荷叶效应;"另一种方法是将表面制有特征尺度为10μm左右微米结构的硅片进行烷基烯酮二聚体(AKD)化处理,该方法获得了具有双微观结构的仿生表面,比较完整地模拟了"荷叶效应."微摩擦性能测试结果表明光滑硅片微观摩擦系数为0.08～0.10,而具有120 nm～25μm微结构的硅片微观摩擦系数为0.04～0.07;具有特征尺度为200 nm线条阵列的粗糙区平均黏附力与光滑区平均黏附力之比为0.59.硅基仿生表面有利于降低摩擦系数和减小黏附,"荷叶效应"对于微机电系统(micro electro mechanical system,MEMS)防黏减摩具有一定的潜在应用价值.     

Superhydrophobic surfaces produced by applying a self-assembled monolayer to silicon micro/nano-textured surfaces

A novel way of producing superhydrophobic surfaces by applying a self-assembled monolayer (SAM) to silicon micro/nano-textured surfaces is presented in this paper. The micro/nano-textured surfaces on silicon substrates were generated by the aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) technique. Octadecyltrichlorosilane (OTS) SAMs were then applied to the textured surfaces by dip coating. The topography and wetting properties of the resulting surfaces were characterized using scanning electron microscopy (SEM) and a video-based contact angle measurement system. The results show that by introducing OTS SAMs on the silicon micro/nano-textured surfaces, superhydrophobic surfaces with water contact angles (WCAs) of 155° were obtained, as compared to the WCAs of OTS-modified smooth silicon surfaces of about 112°. Surface topography was found to directly influence the WCA as predicted by the Cassie-Baxter model.      

化学浴沉积法制备防污自洁聚偏氟乙烯膜

基于"荷叶效应"原理,利用聚偏氟乙烯(PVDF)涂膜构筑微米结构,氧等离子体诱导化学沉积法构筑纳米结构。采用接触角测量仪、原子力显微镜及X光电子能谱仪等研究了PVDF膜表面的微结构及化学组成与疏水性能的关系。结果显示,PVDF溶液涂膜后可形成直径8μm的微球,甲基三氯硅烷修饰的PVDF膜与水的接触角为157°;二甲基二氯硅烷/甲基三氯硅烷混合液修饰的PVDF膜的表面接触角为155°,滚动角2°;集灰实验证明,两种修饰方法制备的PVDF膜均具有良好的防污自洁性能。     

超双疏耐磨PPS基涂层的制备与性能

以NH_4HCO_3为造孔剂,碳纳米管(CNTs)为纳米级纤维填料,采用简单的喷涂工艺制备出超双疏耐磨聚苯硫醚(PPS)基涂层。采用扫描电镜(SEM)、接触角测量仪分析涂层的表面形貌和疏水、疏油性能。采用定载砂纸打磨法测试双疏涂层的耐磨损性能。结果表明:造孔后的涂层表面粗糙,表面的多孔结构和CNTs构成了特殊的微纳二元复合网络结构。当NH_4HCO_3的含量为5%(质量分数)时,涂层实现超疏水和超疏油,对水、甘油和乙二醇的接触角分别为162°,158°和152°。用砂纸反复打磨10000次后,涂层表面轻微磨损,仍保持了高疏水效果,具有良好的耐磨性能。     

Ancillary properties of vapor-deposited carbide coatings

Instrument-size gas-bearing applications demanding hard wear-resistant coatings on lightweight thermally conductive substrates frequently require that properties such as electrical resistivity, magnetic susceptibility and adhesion integrity be evaluated. Titanium carbide and tungsten carbide coatings, approximately 1 to 2 μm thick, were sputter deposited on beryllium oxide substrates. In addition, titanium carbide coatings approximately 50 μm thick were prepared on beryllium oxide substrates by activated reactive evaporation. Electrical resistivity was measured at various locations on the coating surface with a square four-point probe array. Magnetic susceptibility was measured using the Gouy test method in which a specimen is partially suspended in a magnetic field and the resulting force of attraction is measured. Since adhesion integrity is essential to the success of any coating application, a direct tensile pull test was performed on each specimen. The resulting fracture surface showed coating thickness, and the structure and characterization was accomplished by scanning electron microscopy and X-ray analysis.     

AZ51镁合金交流微弧氧化膜层厚度的研究

在氢氧化钾和氟化钾组成的电解液中,采用交流微弧氧化处理技术对AZ51镁合金进行表面处理.研究了处理参数对陶瓷氧化膜层厚度的影响,确定了膜层的组织构成.结果表明:KOH浓度在300~400 g/L时,膜层厚度几乎随着KOH浓度的增加呈线性增长;KF浓度在400~1 000 g/L,膜层厚度增加最快;电压处于50~80 V时,能够促进膜层的快速生长;当电解液温度在20~70℃,随着电解液温度的升高,膜层厚度逐渐增加;膜层厚度随处理时间延长快速增长,超过100 s后趋于平缓.膜层主要由氟化镁和氧化镁组成,致密膜层的最大平均厚度约为30μm,膜层厚度超过30μm后,膜层将出现"沙化层".     

Effects of Multi‐Scale Patterning on the Run‐In Behavior of Steel–Alumina Pairings under Lubricated Conditions

In nature, many examples of multi‐scale surfaces with outstanding tribological properties such as reduced friction and wear under dry friction and lubricated conditions can be found. To determine whether multi‐scale surfaces positively affect the frictional and wear performance, tests are performed on a ball‐on‐disk tribometer under lubricated conditions using an additive‐free poly‐alpha‐olefine oil under a contact pressure of around 1.29 GPa. For this purpose, stainless steel specimens (AISI 304) are modified by micro‐coining (hemispherical structures with a structural depth of either 50 or 95 μm) and subsequently by direct laser interference patterning (cross‐like pattern with 9 μm periodicity) to create a multi‐scale pattern. The comparison of different sample states (polished reference, laser‐patterned, micro‐coined, and multi‐scale) shows a clear influence of the fabrication technique. In terms of the multi‐scale structures, the structural depth of the coarser micro‐coining plays an important role. In case of lower coining depths (50 μm), the multi‐scale specimens show an increased coefficient of friction compared to the purely micro‐coined surfaces, whereas larger coining depths (95 μm) result in stable and lower friction values for the multi‐scale patterns.     

Nanofork for single cells adhesion measurement via ESEM-nanomanipulator system

In this paper, single cells adhesion force was measured using a nanofork. The nanofork was used to pick up a single cell on a line array substrate inside an environmental scanning electron microscope (ESEM). The line array substrate was used to provide small gaps between the single cells and the substrate. Therefore, the nanofork could be inserted through these gaps in order to successfully pick up a single cell. Adhesion force was measured during the cell pick-up process from the deflection of the cantilever beam. The nanofork was fabricated using focused ion beam (FIB) etching process while the line array substrate was fabricated using nanoimprinting technology. As to investigate the effect of contact area on the strength of the adhesion force, two sizes of gap distance of line array substrate were used, i.e., 1 μm and 2 μm. Results showed that cells attached on the 1 μm gap line array substrate required more force to be released as compared to the cells attached on the 1 μm gap line array substrate.     

Soft microelectrode linear array for scanning electrochemical microscopy

A linear array of eight individual addressable microelectrodes has been developed in order to perform high-throughput scanning electrochemical microscopy (SECM) imaging of large sample areas in contact regime. Similar to previous reports, the soft microelectrode array was fabricated by ablating microchannels on a polyethylene terephthalate (PET) film and filling them with carbon ink. Improvements have been achieved by using a 5 μm thick Parylene coating that allows for smaller working distances, as the probe was mounted with the Parylene coating facing the sample surface. Additionally, the application of a SECM holder allows scanning in contact regime with a tilted probe, reducing the topographic effects and assuring the probe bending direction. The main advantage of the soft microelectrode array is the considerable decrease in the experimental time needed for imaging large sample areas. Additionally, soft microelectrode arrays are very stable and can be used several times, since the electrode surface can be regenerated by blade cutting. Cyclic voltammograms and approach curves were recorded in order to assess the electrochemical properties of the device. An SECM image of a gold on glass chip was obtained with high resolution and sensitivity, proving the feasibility of soft microelectrode arrays to detect localized surface activity. Finite element method (FEM) simulations were performed in order to establish the effect of diffusion layer overlapping between neighboring electrodes on the respective approach curves.