疏水性有序介孔氧化硅薄膜的制备

采用溶胶−凝胶技术并结合蒸发诱导自组装工艺, 以三嵌段共聚物EO₂₀PO₇₀EO₂₀ (P123)为模板剂, 使用浸渍提拉法制备了有序介孔氧化硅薄膜, 并使用不同的表面修饰剂对薄膜进行表面处理, 制备了疏水性有序介孔氧化硅薄膜. 利用FT-IR、小角XRD、HRTEM分别表征薄膜的化学物种和孔结构, 探讨了热处理温度和老化时间对薄膜介孔结构的影响, 通过接触角测试研究薄膜的疏水性能, 考察了修饰剂种类、修饰浓度和修饰时间对薄膜疏水性的影响, 结果表明所制备的薄膜为高度有序的介孔氧化硅薄膜, 孔径大小约为8 nm|表面修饰对薄膜的有序性有一定影响, 经三甲基氯硅烷(TMCS)和g-氨丙基三乙氧基硅烷(KH-550)修饰后的薄膜具有很好的疏水性能, 接触角分别为112°和96°|修饰后薄膜的水汽稳定性良好, 仍能保持有序介孔结构, 孔径达7.5 nm, 接触角达93°.     

静电纺丝制备超疏水TiO2纳米纤维网膜

采用静电纺丝技术构筑粗糙表面, 再使用廉价的低表面能物质硅油在煅烧过程中进行同步修饰, 制备出接触角大于150°, 滚动角小于5°的TiO2超疏水表面. 该超疏水表面具有由TiO2纳米纤维和微米尺寸颗粒状硅油高温分解产物织构而成的纳米纤维网膜结构, 这种特殊的微纳米复合粗糙结构和疏水性硅油分解产物的修饰作用导致TiO2纳米纤维网膜的超疏水性. 这种超疏水的TiO2材料为超疏水材料在防水织物、无损失液体运输和微流体等领域的应用提供了新的研究视野.     

硅烷表面修饰引发的ZnO微米棒膜的超疏水性

采用简单的低温水热法制备出ZnO微米棒薄膜,其经辛基三甲氧基硅烷和十二氟庚基丙基三甲氧基硅烷修饰后显示出超疏水性,静态接触角分别为(150±1.3)°和(155±1.5)°,滚动角依次为5°和3°。 ZnO微米棒的微结构和低表面能材料辛基三甲氧基硅烷、十二氟庚基丙基三甲氧基硅烷的表面修饰是其显示超疏水性的原因,用Cassie理论对膜的润湿性进行了分析。     

新型含氟环氧单体的合成及其性能的初步研究

由六氟环氧丙烷二聚体、三聚体分别与4-环己烯-1,2-二甲醇反应合成了2种新型的双全氟烷氧基取代的环氧环己烷衍生物（EFPO1和EFPO2）,其结构经FT-IR和1H NMR确证。 与常见全氟烷基型功能单体不同,此类含氟环氧化合物与环氧树脂预聚物具有良好的相容性并且可改善其疏水性能。 初步考察了上述单体对环氧树脂紫外光固化涂料的改性作用,结果表明,随涂料中含氟单体用量的增加,固化膜的初始水接触角线性增大;其中,EFPO2因其含较长的全氟烷氧基团而具有比EFPO1更好的疏水效果。 如加入1%ＥＦＰＯ２时,固化膜接触角为99°,比未添加含氟单体的固化膜大14°,而相同含量ＥＦＰＯ１固化膜接触角为87°。 当ＥＦＰＯ２含量为5%时,固化膜的疏水性能进一步提高,接触角为113°。 此外,固化膜经加热处理（110 ℃,6 h）后疏水性能明显增强,如ＥＦＰＯ２含量为1%～5%时,固化膜经热处理后,接触角由99°~113°提高至113°~118°,ＥＦＰＯ１固化膜经热处理后接触角也由87°~100°提高至99°~110°。 固化膜疏水性能的提高可能是由于经过加热处理,含氟链段向表面迁移。 由此可见,这类含氟单体可作为表面改性剂应用于涂料、油墨和离型材料。     

Zn片经水热反应和氟硅烷修饰构建超疏水ZnO表面

以乙二胺为溶剂, Zn片在120、140 及160 ℃经水热反应生长出具有蛋糕形、荷叶乳突状、棒状和仙人球状等微结构的ZnO表面. 扫描电镜研究表明, 反应时间越长越有利于形成完整的微纳米结构, 反应温度较高生成的微纳米结构更规整. 140 ℃反应4 h和160 ℃反应5 h的ZnO表面经过氟硅烷修饰后表现出良好的超疏水性, 与水滴的接触角分别达到154.6°和157.3°, 滚动角分别为5°和3°. 该方法因其操作简便、成本低廉, 在锌表面制备特殊微结构和构建超疏水表面具有潜在的应用.     

全氟辛胺修饰石墨烯复合材料的制备、表征及其疏水性能

通过化学法改性石墨烯,用全氟辛胺(FOA)的胺基与氧化石墨烯（GO）的羧基或烷氧基反应制备了含氟石墨烯复合材料（FOA-RGO）,用傅里叶红外光谱、热失重分析、拉曼光谱、高分辨透射电子显微镜（HRTEM）以及原子力显微镜（AFM）对复合材料的结构与形貌进行了表征。 结果表明,FOA已经成功地修饰到石墨烯的边缘。与未修饰的石墨烯相比,水滴在FOA-RGO表面上的接触角从68°提高至118°,显示出良好的疏水性能。     

液相法制备具有双尺寸粗糙度的超疏水铜表面

基于简单的液相法,以硫代硫酸钠和氯化铜为原料在铜片表面上构筑了具有微/纳米双尺寸粗糙度的硫化铜膜.用X射线衍射(XRD)仪、扫描电镜(SEM)、能量色散X射线(EDX)光谱仪及光学视频接触角仪对处理前后的铜表面进行了表征和分析.处理后的超亲水铜表面经硬脂酸修饰后具有超疏水效应,静态接触角高达161°,5μL水滴滚动角低至2.5°左右.超疏水性能归因于表面具有双尺寸粗糙度和低表面能的硬脂酸.该方法简单,无需复杂制备过程和苛刻设备,所得超疏水铜表面具有优异的不粘附性、长时间储存的稳定性和一定的耐摩擦性能.     

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.     

超疏水二氧化钛薄膜的制备及其经紫外光照射引发的超亲水性研究

通过水热反应,在玻璃基底上沉积生成TiO₂薄膜,TiO₂薄膜呈花朵状,具有微纳米级的复合结构,在其表面有大量的乳状突起,经辛基三甲氧基硅烷表面修饰后表现出良好的超疏水性,静态接触角为164°,滚动角为4°。经紫外光照射4~6 h后,其表面变为超亲水性,接触角接近0°。用红外光谱,X射线光电子能谱(XPS)对其表面物质及元素进行表征,最后用Cassie理论对膜的润湿性进行了分析。     

直接浸泡法构筑纯铜的超疏水表面

以棕榈酸-乙醇溶液为疏水剂,利用直接浸泡法在纯铜表面上构筑了超疏水薄膜。 纯铜表面超疏水薄膜的最佳制备条件为：0.03 mol/L棕榈酸-乙醇溶液,室温（20～22 ℃）,浸泡144 h。 通过扫描电子显微镜、接触角测量仪、红外光谱仪和高精密电子天平对超疏水表面进行了表征和分析。 实验结果表明,纯铜试样表面形成了100～200 μm大小的草状棕榈酸铜微簇,接触角达到了150°,其具有较好的抗结垢性能。     

Enhanced wear resistance of sol–gel TiO2 film on a carbon steel in unlubricated sliding against steel ball by stearic acid modification

Increasing wear resistance of steel is of great importance for their practical application. In this paper, we have studied the tribological performance of assembly of stearic acid on a carbon steel coated by sol–gel derived TiO₂ film. The samples were characterized by means of infrared spectroscopy, contact angle measurements, atomic force microscopy and a macro friction and wear tester. Enhanced wear resistance were clearly obtained after functionalization of stearic acid on the TiO₂ surface.     

Adsorption and desorption of stearic acid self-assembled monolayers on aluminum oxide

Development of coatings to minimize unwanted surface adsorption is extremely important for their use in applications, such as sensors and medical implants. Self-assembled monolayers (SAMs) are an excellent choice for coatings that minimize nonspecific adsorption because they can be uniform and have a very high surface coverage. Another equally important characteristic of such coatings is their stability. In the present study, both the bonding mechanism and the stability of stearic acid SAMs on two aluminum oxides (single-crystal C-plane aluminum oxide (sapphire) and amorphous aluminum oxide (alumina)) are investigated. The adsorption mechanism is investigated by ex situ X-ray photoelectron spectroscopy and infrared (IR) spectroscopy. The results revealed that stearic acid binds to sapphire surfaces via a bidentate interaction of carboxylate with two oxygen atoms while it binds to alumina surfaces via both bidentate and monodentate interactions. Desorption kinetics of stearic acid self-organized on both aluminum oxide surfaces into water is explored by ex situ tapping mode atomic force microscopy, IR spectroscopy, and contact angle measurements. The results exhibit that the SAMs of stearic acid formed on sapphire are not stable in water and are continuously lost through desorption. Water contact angle measurements of SAMs that are immersed in water further indicate that the desorption rate of adsorbates from atomically smooth terrace sites is substantially faster than that of adsorbates from the sites of surface defects due to weaker molecular interaction with the smooth surface. A time-dependent desorption profile of SAMs grown on amorphous alumina reveals that contact angles decrease monotonically without any regional distinction, providing further evidence for the presence of adsorption sites with different types of affinity on the amorphous alumina surface.     

Fabrication of superhydrophobic surface of stearic acid grafted zinc by using an aqueous plasma etching technique

A stable superhydrophobic surface of stearic acid grafted zinc was fabricated with two steps, that is, the zinc surface was firstly treated with glow discharge electrolysis plasma (GDEP) and then followed by a grafted reaction of stearic acid onto the treated zinc surface. Results indicated that the wettability of zinc substrate changed from superhydrophily to superhyphodrobicity with a water contact angle (CA) up to 158° and a water sliding angle (SA) less than 5°. The surface morphology and composition were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively.      

Hydrophobic mechanochemical treatment of metallic surfaces wettability measurements as a means of assessing homogeneity

Hydrophobicity, lubrication and anticorrosion properties of steel substrates have been obtained by a deposition of thin film (i.e. by mechanochemical treatment) at room conditions. Stearic acid and paraffin were chosen as reactive molecules. Different abrasive powders were selected to generate active sites on the treated surfaces for adsorption of the reactive molecules and then, the results were compared. The surfaces were analyzed by reflection-absorption infrared spectroscopy (RAIRS). The results emphasize that, a thick layer of mixed stearic acid/paraffin was deposited onto the metallic surface after the treatment. After hexane rinsing we could only detect a very thin layer of oriented stearic acid molecules chemically adsorbed onto the metallic surface and which engages strong interactions with it. Whereas, RAIRS only provides molecular analysis, the XPS technique was complementary for discriminating the different surfaces. It was possible to show differences in thickness as well as in coverage according to the size and shape of abrasive particles. Furthermore, we could conclude that deposit layer is not uniform. Defects were always present and were dependent on abrasive powders used. Then wettability was assessed as a way to test the homogeneity of thin films generated by the mechanochemical treatment. In agreement with theoretical data, receding contact angle was very dependent on the defects in the deposited film. If holes or aggregates were increased in the deposit layer, the receding contact angle was decreased while advancing contact angles and equilibrium contact angles remained constant. A very important point for technological applications was that the homogeneity of the deposited film was governed by abrasive powder involved in mechanochemical treatment and contact angle values were a direct measurement of the homogeneity of surfaces generated by mechanochemical treatment.     

Fabrication of Superhydrophobic Surface with Different Metal Films on Aluminum Alloy

A simple technique was developed for the fabrication of a superhydrophobic surface on the aluminum alloy sheets. Different hierarchical structures(Ag, Co, Ni and Zn) were formed on the aluminum surface by the galvanic replacement reactions. After the chemical modification of them with fluorination, the wettability of the surfaces was changed from superhydrophilicity to superhydrophobicity. Scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and water contact angle measurement were performed to characterize the morphological characteristic, chemical composition and superhydrophobicity of the surfaces. The as-prepared superhydrophobic surfaces showed a water contact angle as high as ca.160° and sliding angle as low as ca.3°. We hope the method to produce superhydrophobic surface can be used in many fields.     

Biomimetic Fabrication of Polymer Film with High Adhesive Superhydrophobicity by Duplicating Locust Wing Surface

Locust is a common flying insect. Locust wings were used as biomimetic templates to fabricate multi-functional polymer(polydimethylsiloxane, PDMS) films by soft lithography. The microstructure and wettability of the natural and artificial locust wing surfaces were investigated by means of a scanning electron microscope(SEM) and a video-based contact angle meter. The natural locust wing surface exhibits complicated hierarchical structures and high adhesive superhydrophobicity(contact angle 152°). The prepared polymer film faithfully reproduces the surface microstructures of the bio-template, and displays a good hydrophobicity and high adhesion(contact angle 144°). The complex wettability of the natural and artificial locust wing surfaces ascribes to the cooperative effect of hydrophobic composition and multi-dimensional rough microstructures. This work not only promotes our understanding of the wetting mechanism on bio-surfaces, but offers an inexpensive and effective approach for biomimetic fabrication of multi-functional interfacial materials.     

类荷叶结构聚全氟乙丙烯的超疏水性

以聚二甲基硅氧烷（PDMS）复制的荷叶表面微结构为阴模模板,将聚全氟乙丙烯（FEP）粉体置于该阴模模板上,在约0.3 N/cm2的压力,280 ℃和-0.1 Mpa真空度的条件下热压成型,成功制备了具有类荷叶结构的FEP表面。扫描电镜观察结果表明, FEP表面与荷叶表面微结构具有很大的相似性,该表面具有良好的超疏水性,与水的接触角达到168°,滚动角小于3°,而且具有良好的疏酸、疏碱、疏盐溶液性能和稳定性,即使在溶液中长期浸泡而失活后,经piranha洗液处理约10 min,其表面超疏水、疏酸、疏碱性能也可迅速恢复。PDMS的热重分析结果表明,PDMS阴模在热压条件下失重极小,可重复使用。因此,将FEP的耐酸、耐碱、耐腐蚀和低表面能的特性与荷叶表面的特殊结构有机结合,在制备抗粘附、自清洁容器等方面具有广泛的应用前景。     

Immobilization of Bovine Serum Albumin on Poly(ether ether ketone)for Surface Biocompatibility Improvement

UV-induced graft polymerization of acrylic acid(AA)on poly(ether ether ketone)(PEEK)films was carried out to introduce-COOH for the subsequent immobilization of bovine serum albumin(BSA).BSA was introd...     

Self‐assembly of stearic acid on aluminium: the importance of oxide surface chemistry

The influence of ambient atmospheric exposure on the chemistry of the magnetron‐sputtered aluminium surface has been characterized as hydroxyl incorporation to the oxide surface and concurrent adsorption of airborne carbonaceous contamination. Here, the consequence of these changes in oxide surface chemistry upon the adsorption of stearic acid from solution is investigated. Water contact angle and polarization modulation infrared refection–absorption spectroscopy (PM‐IRRAS) reveal a strong dependence of stearic acid monolayer order upon ambient exposure time prior to assembly. It is proposed that hydroxyl formation in the ambient atmosphere increases the stearic acid adsorption density and thus the self‐assembled monolayer (SAM) order, whereas airborne carbonaceous material blocks these adsorption sites and introduces disorder in the monolayers through a decrease in adsorption density. Monolayer adsorption has been correlated with the aluminium oxide surface chemistry. It is proposed that this phenomenon represents an explanation for the irreproducible results often reported for assembly on metal oxide substrates. Furthermore, it indicates that in this broad class of material surfaces assembly can be used as a means of estimating the reactivity of surfaces with respect to organic overlayers such as paints and adhesives. Removal of adsorbed carbonaceous material from the aluminium surface using an oxygen plasma resulted in a significantly increased order of the stearic acid monolayer, as assessed by water contact angle. This observation is rationalized as the removal of carbonaceous material blocking surface adsorption sites by the plasma, but retention of the underlying hydroxyl functionality. This is predicted to have important implications in the preparation of aluminium for painting and adhesive bonding. Copyright © 2004 John Wiley & Sons, Ltd.     

Supramolecular architecture in Langmuir and Langmuir-Blodgett films incorporating a chiral azobenzene

This article describes the synthesis and fabrication of Langmuir and Langmuir-Blodgett (LB) films incorporating a chiral azobenzene derivative, namely, ( S)-4- sec-butyloxy-4'-[5'-(methyloxycarbonyl)pentyl-1'-oxy]azobenzene, abbreviated as AZO-C4(S). Appropriate conditions for the fabrication of monolayers of AZO-C4(S) at the air-water interface have been established, and the resulting Langmuir films have been characterized by a combination of surface pressure and surface potential versus area per molecule isotherms, Brewster angle microscopy, and UV-vis reflection spectroscopy. The results indicate the formation of an ordered trilayer at the air-water interface with UV-vis reflection spectroscopy showing a new supramolecular architecture for multilayered films as well as the formation of J aggregates. Films were transferred onto solid substrates, with AFM revealing well-ordered multilayered films without 3D defects. Infrared and UV-vis absorption spectroscopy indicate that the supramolecular architecture may be favored by the formation of H bonds between acid groups in neighboring layers and pi-pi intermolecular interactions. Circular dichroism spectra reveal chiro-optical activity in multilayered LB films.