Oskarsson H, Holmberg K
Chalmers University of Technology, Department of Chemical and Biological Engineering, Applied Surface Chemistry, SE-412 96 Göteborg, Sweden.
J Colloid Interface Sci. 2006 Sep 15;301(2):360-9. doi: 10.1016/j.jcis.2006.05.045. Epub 2006 May 24.
Adsorption of a series of ethoxylated cationic surfactants at model surfaces of alkanethiol self-assembled monolayers was studied by the surface plasmon resonance technique. Model surfaces were tailor-made by choosing alkanethiols or mixtures of alkanethiols with methyl, hydroxyl, carboxyl, and trimethylammonium groups in terminal position. The ethoxylated and quaternized cationic surfactants having from 2 to 18 oxyethylene units, showed a decrease in adsorbed amount with increasing oxyethylene chain length for both hydrophobic and hydrophilic surfaces. On a negatively charged surface, containing carboxylate groups, the surfactant with only two oxyethylene groups adsorbed strongly due to electrostatic attraction and the adsorption increased with increasing amount of surface carboxylate groups. This work shows the usefulness of self-assembled alkanethiols on gold as a tool for performing surfactant adsorption studies on surfaces with variable hydrophobicity and charge.
采用表面等离子体共振技术研究了一系列乙氧基化阳离子表面活性剂在烷硫醇自组装单分子膜模型表面的吸附情况。通过选择末端带有甲基、羟基、羧基和三甲基铵基团的烷硫醇或烷硫醇混合物来定制模型表面。对于疏水和亲水表面，具有2至18个氧化乙烯单元的乙氧基化和季铵化阳离子表面活性剂的吸附量均随氧化乙烯链长的增加而减少。在含有羧酸根基团的带负电荷表面上，仅含两个氧化乙烯基团的表面活性剂由于静电吸引而强烈吸附，且吸附量随表面羧酸根基团数量的增加而增加。这项工作表明，金表面的自组装烷硫醇作为一种工具，可用于在具有可变疏水性和电荷的表面上进行表面活性剂吸附研究。
