柱状结构阵列碳纳米管膜的超疏水性研究

浸润性是固体表面的重要性质之一 .决定固体表面的浸润性的两个主要因素中 ,化学性质是内因 ,而几何结构形貌也是不可缺少的重要因素 .通过改变固体表面的粗糙度可以改变其浸润性 [1～ 5] .通常 ,人们用水接触角的大小来衡量固体表面水的浸润性 ,水与固体表面的接触角大于 1 5     

光响应性超疏水偶氮苯自组装多层膜的制备及性质研究

近年来,偶氮苯类化合物的光学顺反异构现象已引起人们的广泛关注[1~7].在紫外光照射下,偶氮苯由反式结构转变为顺式结构,引起分子的偶极矩发生变化,导致分子的吸收光谱、尺寸及表面能等均发生变化[7].偶氮苯表面能的改变可引起其表面浸润性发生变化.据文献[1~4]报道,偶氮苯膜在紫外光照射前后接触角最大改变了11°.浸润性是固体表面的一个重要特性,主要受固体表面的化学组成和微观几何结构(粗糙度)影响[8~11].通常,与水的接触角大于150°的表面称为超疏水表面;而与水的接触角小于5°的表面称为超亲水表面.本文以2-(4-偶氮苯基苯氧基)丙烯酸…     

碳纳米管负载高分散Pt纳米颗粒的制备及表征

近年来,碳纳米管(CNTs)[1]作为新型催化剂载体方面的研究[2～11]受到了广泛关注。由于碳纳米管具有纳米级卷曲的表面,与石墨烯相比其表面π键发生变化,从而导致新的电子结构[12],因此碳纳米管负载的催化剂在涉及电子传输过程的催化过程中具有特别的吸引力。燃料电池电极催化剂就是其中典型的一类[13～15]。已有研究者选用碳纳米管作为载体,将Pt[16～19]、PtRu[20,21]等具有催化活性的贵金属或其合金负载到碳纳米管上,展现出了很好的电催化氧化活性。然而,到目前为止,制备用于燃料电池的具有均匀尺寸和分散性的负载型纳米催化剂仍然是一项…     

单层碳纳米管的化学修饰

单层碳纳米管 (SWNT)是 Iijima博士 [1]于 1 993年首次发现的 .它具有非常独特的物理和化学性质 ,因而成为近年来研究的热点问题 .随着单层碳纳米管的合成技术和纯化研究的不断完善 [2～ 5] ,关于它的研究方向开始转向化学反应和应用研究 .由于单层碳纳米管不溶于水或有机溶剂而限制了对其化学性质的研究 .单层碳纳米管的端头是由碳的五元环和六元环组成的半球形 .氧化作用可将该端头打开并转化为羧基 ,从而与其它的化学试剂发生反应 .Liu Jie等 [6] 用浓硫酸和浓硝酸的混合物氧化单层碳纳米管 ,将之裁剪成 1 50～ 80 0 nm的“短管”.在…     

表面富集季胺盐的交联聚苯乙烯微球合成与表征及其溶胀行为研究

在聚合物微球表面引入不同的基团 (如亲水性的羟基或羧基 ) ,可以改善聚合物微球的稳定性甚至生物相容性[1～ 4] ;利用表面基团可以把无机半导体微粒和功能有机分子以及生物分子引入聚合物微球[5～ 8] ,赋予聚合物微球特殊的性能 ,使其广泛应用于涂料、光电功能材料和生物医用材料等领域[9～ 15] .其中 ,表面带有阳离子的聚合物微球在絮凝剂、胶粘剂、水性涂料等方面已经得到广泛研究[16～ 2 0 ] .通常阳离子聚合物微球可以根据不同的需要利用常规乳液聚合、核壳乳液聚合等方法来合成 .亲水性和疏水性单体进行的无皂乳液聚合[2 1] ,因其能在…     

阵列聚合物纳米柱膜的超疏水性研究

浸润性(又称润湿性,Wettability)是固体表面的一个重要特征,它主要由表面化学组成和表面的几何结构两方面控制^[1～5].近年来,超疏水性固体表面由于在防雪、防污染、抗氧化以及防止电流等方面都有非常广阔的应用前景,引起了人们的极大关注[6～11].     

微波等离子体辅助化学气相沉积法低温合成定向碳纳米管阵列

自碳纳米管被发现以来[1] ,这种准一维纳米新材料由于其优异的力学、电学、储氢等理化性质而显示出非常重要的理论研究与实际应用价值[2 ,3] .碳纳米管阵列更可作为场致发射器件 ,有望应用于冷阴极平板显示器或纳米电子学等前沿领域[4 ] ,成为碳纳米管研究中的热点 .在已有报道的多种制备碳纳米管阵列的方法中 ,以孔性硅或孔性 Al2 O3作为模板剂 ,通过化学气相沉积制备的方法较为普遍[5～ 7] ,但此类方法往往需要在较高温度 (高于 70 0℃[6 ,7] )下进行 ,对于碳纳米管阵列最诱人的应用前景之一平板显示器而言 ,要求在显示玻璃表面直接生长…     

碳纳米管向金刚石纳米晶粒的转变

在碳60（C60）[1]和碳纳米管(CNTs)[2]发现之前,人们知道碳通常显示石墨和金刚石两种晶体结构.自从C60和碳纳米管发现后,由于其独特的纳米结构而具有广泛的应用前景,国内外许多学者致力于研究它们的物理和化学特性,而C60、巴基葱（多层碳纳米球）、碳纳米管和金刚石之间的转变是所研究的焦点之一.目前,由碳的其他形式向金刚石转变的主要方法有：Meilunas等人[3]以C60和C70薄膜为基底气相生长多晶金刚石,C60和C70的稳定性和微平面结构在外界条件下,有利于金刚石成核和外延生长;Banhart[4]小组研究了在电子束辐射作用下巴基葱转变…     

针尖化学方法研究单壁碳纳米管末端羧基的解离性质

针尖化学利用化学手段对扫描探针显微镜 ( SPM)的针尖进行功能化修饰 ,将其作为化学反应的“探针”用于研究表面的局域化学反应性质、跟踪表面发生的化学反应过程等 [1] .用针尖化学技术来研究自组装膜 ( SAMs)表面酸碱基团的局域解离性质 ,称之为化学力滴定 [2～ 8] .利用表面缩合方法将单壁碳纳米管短管组装到 AFM针尖上 ,通过测定针尖上碳纳米管的末端基团与羟基自组装膜表面之间的粘滞力 ,研究碳纳米管末端羧基的解离性质 ,可得到碳纳米管结构与化学性质的信息 .1　实验部分1 .1　碳纳米管针尖和羟基末端自组装膜的制备　基底 [Si( …     

浸润性可调的导电聚苯胺/聚丙烯腈同轴纳米纤维

聚苯胺(PANI)因其具有可调的导电性、优异的化学稳定性、简单的制备方法等特点, 在化学电源、抗静电涂层、电磁屏蔽材料、抗腐蚀、传感器等领域具有广泛的应用前景[^1~4]. 由于聚苯胺的刚性分子链使得聚苯胺几乎不溶不熔, 难以加工应用, 因此, 将导电聚合物直接制成纳米纤维一直是合成纤维界所希望的目标之一. 此外, 由于材料尺度的减小, 使纳米材料的表面与界面性质,尤其是表面浸润性变得更为突出.浸润性是固体表面的重要特征之一, 它主要由表面的化学组成和微观结构共同决定^[5,6]. 可调的浸润性在超疏水材料、药物传输、仿生材料和微流体等领域具有重要的应用价值^[7~10] , 引起人们广泛关注.     

Contact line shape on ultrahydrophobic post surfaces

In this work, we investigate the configuration of the contact line of a water drop lying on an ultrahydrophobic post surface using the numerical algorithm Surface Evolver. For the special situation of Cassie wetting, we propose a modified definition of the contact line as the line in space where the meniscus starts to curve upward out of the plane of the composite surface. In our simulations, it is found that the contact line is very strongly distorted, indicating a strong tendency of the drop to "ball up" in those areas where it is not in contact with the solid surface. The distortion of the contact line corresponds to a pronounced deformation of the liquid-air interface around the base of the drop. We discuss the consequences of this distortion for the definition and practical measurement of the contact angle on ultrahydrophobic surfaces.     

Superhydrophobic thermoplastic polyurethane films with transparent/fluorescent performance

In this paper, we report a simple and versatile route for the fabrication of superhydrophobic thermoplastic polyurethane (TPU) films. The approach is based on octadecanamide (ODAA)-directed assembly of nanosilica/TPU/ODAA hybrid with a well-defined sheetlike microstructure. The superhydrophobic hybrid film shows a transparent property, and its water contact angle reaches as high as 163.5° without any further low surface energy treatment. In addition, the superhydrophobic TPU hybrid film with fluorescent properties is achieved by smartly introducing CdTe quantum dots, which will extend potential application of the film to optoelectronic areas. The resulting fluorescent surface produced in this system is stable and has a water contact angle of 172.3°. This assembly method to control surface structures represents an intriguing and valuable route to tune the surface properties of organic-inorganic hybrid films.     

Photochemical modification of diamond films: introduction of perfluorooctyl functional groups on their surface

Photolysis of perfluoroazooctane with diamond films led the chemical modification of the surface to introduce perfluorooctyl functional groups, confirmed by means of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and time-of-flight secondary ion mass spectrometry measurements. Diamond films modified with fluorine moieties showed improved frictional property and reduction of surface energy, as evaluated by contact angle to water, compared with a pristine diamond film. The contact angle and friction coefficient of chemically modified diamond film are 118 degrees and 0.1, respectively. The results of the value of the contact angle depending on irradiation times are consistent with those of the F/C ratio of fluorinated diamond films by monitoring with XPS.     

Condensation on ultrahydrophobic surfaces and its effect on droplet mobility: ultrahydrophobic surfaces are not always water repellant

The condensation of water was studied on topography-based ultrahydrophobic surfaces containing hydrophobized silicon pillars. Optical microscopy showed that water nucleated and grew both on top of and between the pillars. As condensation progressed, water between the pillars became unstable and was forced upward to the surface. Macroscopic water droplets on top of the pillars coalesced with condensed water that remained between the pillars, pinning the droplets at their three-phase contact line. Dynamic contact angle measurements on ultrahydrophobic surfaces wet with condensation revealed a dramatic increase in hysteresis compared to that on dry surfaces, leading to a corresponding decrease in water drop mobility.     

铝合金表面原位自组装超疏水膜层的制备及耐蚀性能

采用阳极氧化法在铝合金表面原位构造粗糙结构, 经表面自组装硅氧烷后得到超疏水自清洁表面, 与水滴的接触角最大可达157.5°±2.0°, 接触角滞后小于3°. 通过傅立叶变换红外(FT-IR)光谱分析仪、场发射扫描电子显微镜(FE-SEM)、能谱仪(EDS)、原子力显微镜(AFM)和接触角测试对阳极氧化电流密度、硅氧烷溶液中水的含量和自组装时间等参数进行了分析, 并得到制备超疏水自清洁表面的最优工艺参数. FE-SEM及AFM的测试结果表明, 由自组装硅氧烷膜层的无序性形成的纳米结构和阳极氧化构造的微米级粗糙结构与硅氧烷膜层的低表面能的协同作用构成了稳定的超疏水表面. 电化学测试(动电位极化)的结果表明, 原位自组装超疏水膜层极大地提高了铝合金的耐蚀性.     

Exceptional superhydrophobicity and low velocity impact icephobicity of acetone-functionalized carbon nanotube films

We present a simple method to produce carbon nanotube-based films with exceptional superhydrophobicity and impact icephobicity by depositing acetone-treated single-walled carbon nanotubes on glass substrates. This method is scalable and can be adopted for any substrate, both flexible and rigid. These films have indicated a high contact angle, in the vicinity of 170°, proved both by static and dynamic analysis processes. The dynamic evaporation studies indicated that a droplet deposited on the treated films evaporated in the constant contact angle mode for more than 80% of the total evaporation time, which is definitely a characteristic of superhydrophobic surfaces. Furthermore, the acetone-functionalized films showed a strong ability to mitigate ice accretion from supercooled water droplets (-8 °C), when the droplets were found to bounce off the films tilted at 30°. The untreated nanotube films did not indicate similar behavior, and the supercooled water droplets remained attached to the films' surfaces. Such studies could be the foundation of highly versatile technologies for both water and ice mitigation.     

聚氧化丙烯醚对SiO2减反膜性质的影响

采用溶胶-凝胶制备的SiO2减反膜具有优良的光学特性和高损伤阈值,可以用做高反膜和减反膜的低折射率匹配层.在高功率激光领域具有十分诱人的应用前景.     

An Ultrahydrophobic Fluorous Metal–Organic Framework Derived Recyclable Composite as a Promising Platform to Tackle Marine Oil Spills

Derived from a strategically chosen hexafluorinated dicarboxylate linker aimed at the designed synthesis of a superhydrophobic metal–organic framework (MOF), the fluorine‐rich nanospace of a water‐stable MOF ( UHMOF‐100 ) exhibits excellent water‐repellent features. It registered the highest water contact angle (≈176°) in the MOF domain, marking the first example of an ultrahydrophobic MOF. Various experimental and theoretical studies reinforce its distinctive water‐repellent characteristics, and the conjugation of superoleophilicity and unparalleled hydrophobicity of a MOF material has been coherently exploited to achieve real‐time oil/water separation in recyclable membrane form, with significant absorption capacity performance. This is also the first report of an oil/water separating fluorinated ultrahydrophobic MOF‐based membrane material, with potential promise for tackling marine oil spillages.     

Fabrication of superhydrophobic polymer films with hierarchical silver microbowl array structures

Flexible superhydrophobic polyvinyl alcohol (PVA) films with silver bowl-like array structure are fabricated based on the thermal evaporation with sphere monolayer as templates and the modification of 1H, 1H, 2H, 2H-perfluorodecanethiol on silver surface. The silver microbowl arrays were composed of silver nanoparticles with an average diameter size of ca. 10 nm. The polymer films exhibit excellent stability and remarkable superhydrophobicity with a high water contact angle (CA) of about 163° and a low sliding angle (SA) of less than 3°.     

PREPARATION AND SURFACE PROPERTIES OF ACRYLIC COPOLYMERS CONTAINING FLUORINATED MONOMERS

A series of copolymers comprising butylmethacrylate, styrene, butylacrylate, hydroxypropyl acrylate and perfluoroalkyl methacrylate were synthesized by the free radical polymerization using BPO as an initiator. The surface property of the copolymer films was subsequently characterized. The contact angle measurements and energy dispersive analysis of X-ray （EDAX） show that the length and content of perfluoroalkyl side chains in the copolymers are crucial for the preparation of the film with low surface energy. At a given content of fluorinated monomers in the copolymers, the longer the perfluoroalkyl side chain, the larger the water contact angle of the copolymer films will be. On the other hand, the higher the content of fluorinated monomers, the lower the surface energy is. The water contact angle increases with the increase of the fluorinated monomer content and reaches a plateau at 3 wt% of fluorinated monomer content.