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A novel super-hydrophobic stearic acid (STA) film with a water contact angle of 166o was prepared by chemical adsorption on aluminum wafer coated with polyethyleneimine (PEI) film. The micro-tribological behavior
of the super-hydrophobic STA monolayer was compared with that of the polished and PEI-coated Al surfaces. The effect of relative
humidity on the adhesion and friction was investigated as well. It was found that the STA monolayer showed decreased friction,
while the adhesive force was greatly decreased by increasing the surface roughness of the Al wafer to reduce the contact area
between the atomic force microscope (AFM) tip and the sample surface to be tested. Thus the friction and adhesion of the Al
wafer was effectively decreased by generating the STA monolayer, which indicated that it could be feasible and rational to
prepare a surface with good adhesion resistance and lubricity by properly controlling the surface morphology and the chemical
composition. Both the adhesion and friction decreased as the relative humidity was lowered from 65% to 10%, though the decrease
extent became insignificant for the STA monolayer.
The project supported by the National Natural Science Foundation of China (50375151, 50323007, 10225209) and the Chinese Academy
of Sciences (KJCX-SW-L2) 相似文献
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超疏水涂膜的研究进展 总被引:5,自引:0,他引:5
超疏水涂膜以其独特的性能,在国防、工农业生产和日常生活中有着广泛的应用前景。但目前的制备技术制约了其在建筑外墙涂料等大型设施方面的应用。探索如何采用简单有效的方法构造和调控涂膜的双微观结构,从而获得性能持久优异的超疏水性涂膜,并有效应用于生产和生活的各个方面是这一领域研究的最终目标。本文就超疏水材料表面理论的发展和近几年来超疏水膜制备技术取得的新成果进行了概括,并指出制备超疏水涂膜存在的问题和发展方向。利用表面能极低的含氟材料,将溶胶-凝胶、相分离技术和自组装梯度功能等技术有机结合,获得适宜的表面粗糙度和微观构造,是实现超疏水涂膜工业化生产的可行途径。 相似文献
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Abstract The presence of vitamin K1 in human body is important for preventing the hemorrhagic disease. Due to its very long side chain, vitamin K1 is highly insoluble in water. We have successfully dissolve a substantial amount of vitamin K1 in solutions of a commercial surfactant containing carboxymethyl ethoxylates (Hüls B433) and obtained low interfacial tension (IFT) and stable emulsion systems. This paper will present the details of these experiments. The solubilization of vitamin K1 was estimated from UV absorption. The IFT values were measured by using a spinning drop apparatus and all particle sizes were determined by using laser light scattering. By using the Hüls B433 surfactant and an optimum amount of CaCl2, we can dissolve vitamin K1 in water and obtain low IFT systems in the order of 10?2 dyne/cm. The emulsions obtained in these systems are stable and contain droplet sizes below 65 nm. The dissolution of vitamin K1 and the IFT behavior in these systems follow the rules for crude oil and prefer larger surfactant micelles. 相似文献
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疏水表面纳米气泡的运动有重要的应用价值和研究意义。本文采用分子动力学方法,模拟了纳米通道壁面为超疏水性时壁面上气泡的运动状况。在质量力驱动下,随着外界驱动力的增大,两壁面上的气泡被逐渐拉长,同时逐渐变得扁平;前端"接触角"逐渐增大,而后端"接触角"逐渐减小。纳米通道内疏水性表面的纳米气泡随着外部驱动力的变化呈现出不同的形态,变化程度随着驱动力的增大而增大。在不同驱动力作用下,两个气泡总是保持相同的速度,气泡的速度与外力驱动的大小呈线性增长趋势。随着外力的增大,边界层及通道中心速度皆呈现增大趋势。 相似文献
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Hongwei Chang Yannan Zhou Xiaoli Zheng Wei Liu Prof. Qun Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(61):e202201811
The development of an efficient strategy for fabricating two-dimensional metal-organic framework (MOF) nanosheets with high yield and high stability is desirable. Herein, we demonstrate for the first time that large, single-layer 2D nickel-benzene dicarboxylate (Ni−BDC) MOF nanosheets can be fabricated with the assistance of supercritical (SC) CO2 in a pure aqueous system. Detailed experimental evidence reveals that the SC CO2 molecule can exchange with the lattice-coordinated H2O molecules, side-on coordinate with the metal Ni1 sites on the Ni−BDC surface, and finally break the interlayer hydrogen bond to exfoliate the bulk Ni−BDC into a 2D MOF. More importantly, a thin SC CO2 layer building up at the water−Ni−BDC interfaces can transform the pristine hydrophilic interface into a super-hydrophobic one. This super-hydrophobic layer at the water-MOF interface can effectively prevent dissociation, thus promoting the stability of Ni−BDC in aqueous system. 相似文献
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含氟环氧树脂杂化纳米二氧化硅超疏水材料的制备与性能 总被引:1,自引:0,他引:1
目前超疏水材料的制备方法大都存在着制备工艺复杂的缺点。 本文采用传统自由基聚合方法,以甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)为单体,合成具有交联性的前驱聚合物P(GMA-r-St)。 再用三氟乙酸(TFA)对其进行接枝改性,制备含氟环氧聚合物P(GMA-r-St)-g-TFA。 利用γ-氨丙基三乙氧基硅烷(KH-550)改性纳米二氧化硅(SiO2),对其进行傅里叶变换红外光谱(FTIR)、热重(TG)表征。 氨基改性的纳米二氧化硅与含氟环氧聚合物混合制备的超疏水改性材料,棉织物表面经其浸泡,可快速构建超疏水结构。 通过改变改性纳米颗粒的含量,探究其构筑的棉织物的疏水性能和耐溶剂性能。 研究结果表明,经浸泡改性的棉织物,水接触角为160°,耐溶剂性时间为130 min,具备很好的耐溶剂性。 该方法可广泛应用于多种基底材料表面的疏水改性。 相似文献