Fundamental studies on the removal of an oily contaminant in aqueous solutions by the application of the LB technique

应用Langmuir-Blodgett技术构建了一个定义明确的模型系统，研究了水溶液中含油污染物的去除过程.用γ -氨丙基三乙氧基硅烷（APTES）和甲基三乙氧基硅烷（MTES）对石英玻璃板进行表面处理。硅烷化降低了基底的润湿性。在水中，未经处理和经MTES处理的二氧化硅玻璃带负电荷，经APTES处理的玻璃带正电荷。花生酸被用作模型油污染物。获得了花生酸单分子膜的表面压力-面积等温线和布鲁斯特角显微图像，并采用垂直浸渍法将固体凝聚膜转移到基底上。将具有LB膜的基底在水溶液中超声洗涤。从FT-IR光谱的变化评价的去污力作为硅烷化的结果，特别是对于APTES的基板下降 关于我们 经过处理的玻璃。基底的润湿性和表面电荷对去污力起重要作用。从APTES处理的玻璃的LB膜的去除增加，增加表面活性剂或乙醇浓度。去除率强烈依赖于温度。将花生酸单层膜转移到石英晶体微天平（QCM）的金电极上，然后在含有氯化钠、氢氧化钠、表面活性剂和/或乙醇的水溶液中清洗QCM。从QCM的频率变化的去污力进行了评价。去污力有一个很好的相关性与自由能的变化，由于花生酸膜和金表面之间的接触区，这是使用实验确定的接触角和表面自由能计算的薄的液体层的渗透。花生酸的碱皂化作用和渗透作用对油的去除有一定的作用。将172 nm UV准分子暴露在空气中并随后超声洗涤对于去除是有效的。少

A well-defined model system was constructed by the application of the Langmuir-Blodgett technique to investigate the removal processes of oily contaminants in aqueous solutions.. Silica glass plates were treated with γ -aminopropyltriethoxysilane (APTES) and methyltriethoxysilane (MTES). The wettability of the substrates decreased by the silanization. Untreated and MTES-treated silica glass were negatively charged and APTES-treated glass was positively charged in water. Arachidic acid was used as a model oily contaminant. The surface pressure-area isotherms and the Brewster angle microscopic images of the spreading monolayers of arachidic acid on water were obtained, and the solid-condensed films were transferred onto the substrates by the vertical dipping method. The substrates with the LB films were ultrasonically washed in aqueous solutions. The detergency evaluated from the change in FT-IR spectra of the substrate decreased as a result of the silanization, especially for the APTES … More treated glass. The wettability and the surface charge of the substrate played important roles in the detergency. The removal of the LB films from the APTES-treated glass increased with increasing surfactant or ethanol concentration. The removal rate was strongly dependent on temperature. The monolayers of arachidic acid were transferred onto the gold electrodes of the quartz crystal microbalance (QCM) and then the QCM was cleaned in aqueous solutions containing sodium chloride, sodium hydroxide, surfactants and/or ethanol. The detergency was evaluated from the frequency change of the QCM.The detergency had a good correlation with the free energy change due to the penetration of a thin liquid layer between the arachidic acid films and the gold surface in the zone of contact, which was calculated using the experimentally determined contact angles and surface free energies. The saponification of arachidic acid by alkali as well as the penetration was shown to contribute to the oil removal. The exposure of the 172 nm UV eximer in air and the following ultrasonic washing were effective for the removal. Less