Capistran Briana A, Blanchard G J
Department of Chemistry , Michigan State University , 578 S. Shaw Lane , East Lansing , Michigan 48824 , United States.
Langmuir. 2019 Mar 5;35(9):3346-3353. doi: 10.1021/acs.langmuir.9b00022. Epub 2019 Feb 21.
The influence of the copper(II) ion on the formation, morphology, and organization of an arachidic acid monolayer was investigated using Langmuir-Blodgett (LB) monolayers, Π-A isotherms, and Brewster angle microscopy (BAM). Our findings indicate that a Cu-complexed LB film exhibits an order that depends on the subphase pH, analogous to other metal ions. Yazdanian , M. ; et al. Ionic Interactions of Fatty Acid Monolayers at the Air-Water Interface . Langmuir 1990 , 6 , 1093 - 1098 . Kurnaz , M. L. ; et al. Morphology of Microphase Separation in Arachidic Acid-Cadmium Arachidate Langmuir-Blodgett Multilayers . J. Phys. Chem. 1996 , 100 , 11113 - 11119 . The metal ion facilitates the formation of solid-phase films at surface pressures as low as 5 mN/m. The films exhibit a rigid, ordered phase, evidenced by the absence of a collapse point and an increase in surface pressure rather than the typical sharp decrease in surface pressure, indicative of film failure. Amphiphile ionic charge vs pH (i.e., the extent of arachidic acid protonation) plays a role in the observed absence of collapse and the ability of the films to maintain order and cohesion at high surface pressures (ca. 65 mN/m). Additionally, film thickness data suggest that the incorporation of Cu ions induces a change in orientation of the aliphatic chains of the amphiphiles and that amphiphile solubility in the subphase may play a role in the observed film behavior at low surface areas and high pH.
利用朗缪尔-布洛杰特（LB）单分子层、Π-A等温线和布鲁斯特角显微镜（BAM）研究了铜（II）离子对花生酸单分子层的形成、形态和组织的影响。我们的研究结果表明，与其他金属离子类似，铜络合的LB膜表现出一种取决于亚相pH值的有序性。亚兹达尼亚，M.；等人。脂肪酸单分子层在气-水界面的离子相互作用。《朗缪尔》1990年，6卷，1093 - 1098页。库尔纳兹，M.L.；等人。花生酸-镉花生酸酯朗缪尔-布洛杰特多层膜中的微相分离形态。《物理化学杂志》1996年，100卷，11113 - 11119页。金属离子有助于在低至5 mN/m的表面压力下形成固相膜。这些膜表现出刚性的有序相，这可通过不存在塌陷点以及表面压力增加而非典型的表面压力急剧下降（表明膜失效）来证明。两亲离子电荷与pH值的关系（即花生酸的质子化程度）在观察到的无塌陷现象以及膜在高表面压力（约65 mN/m）下保持有序和凝聚的能力中起作用。此外，膜厚度数据表明，铜离子的掺入导致两亲物脂肪链取向的变化，并且两亲物在亚相中的溶解度可能在低表面积和高pH值下观察到的膜行为中起作用。
