The production of stable hydrophobic surfaces by the adsorption of hydrocarbon and fluorocarbon carboxylic acids onto alumina substrates
The production of stable hydrophobic surfaces by the adsorption of hydrocarbon and fluorocarbon carboxylic acids onto alumina substrates
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DOI：
10.1016/s0927-7757(00)00821-9
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发表时间：
2001-06-30
影响因子：
5.2
通讯作者：
Pashley, RM
中科院分区：
文献类型：
--
作者：
Karaman, ME;Antelmi, DA;Pashley, RM
研究了各种羧酸在氧化铝基体上的吸附，作为研究远距离疏水相互作用的模型体系。采用经典吸附等温线、接触角测量和胶体探针原子力显微镜研究了吸附过程。羧酸与存在于氧化铝表面的羟基形成酯，并根据酸的功能产生具有一系列疏水性和稳定性的表面。Langmuir吸附模型充分描述了烃类羧酸的吸附，并产生了不同疏水性的稳定表面，可以抵抗水的溶解。相比之下，从水溶液中吸附的氟酸产生的疏水表面并不总是稳定的，尽管在非水溶剂中在高温下进行化学吸附时，其稳定性大大提高。这些氟化羧酸的吸附产生了最疏水的表面。涂有吸附丙酸的氧化铝表面之间的相互作用力与DLVO理论预期的一样，没有疏水力的证据。(C) 2001 Elsevier Science B.V.版权所有
The adsorption of various carboxylic acids onto alumina substrates has been studied as a model system for the study of the long range hydrophobic interaction. The adsorption was studied using classical adsorption isotherms, contact angle measurements and colloid probe atomic force microscopy. Carboxylic acids form esters with the hydroxyl groups present on the alumina surface and produce surfaces with a range of hydrophobicities and stabilities depending on the acid's functionality. Hydrocarbon carboxylic acid adsorption was found to be adequately described by the Langmuir adsorption model and produced stable surfaces of varying hydrophobicities which resisted dissolution by water. By comparison, hydrophobic surfaces produced with fluorinated acids adsorbed from aqueous solution were not always stable, although their stability was greatly improved when the chemisorption was carried out in a non-aqueous solvent at elevated temperatures. Adsorption of these fluorinated carboxylic acids produced the most hydrophobic surfaces. Interaction forces between alumina surfaces coated with adsorbed propionic acid were as expected from DLVO theory with no evidence of hydrophobic forces. (C) 2001 Elsevier Science B.V. All rights reserved.