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

应用Langmuir-Blodgett技术建立了一个定义良好的模型系统来研究水溶液中油性污染物的去除过程。用γ -氨基丙基三乙基氧基硅烷（APTES）和甲基三乙基氧基硅烷（MTES）处理硅基玻璃板。硅烷化降低了基质的润湿性。未经处理和mtes处理的硅玻璃带负电，而aptes处理的玻璃在水中带正电。以花生酸为模型油类污染物。获得了花生酸单分子膜在水中铺展的表面压力-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衬底上。用超声波在水溶液中清洗含有LB膜的衬底。由于硅烷化，基片的FT-IR光谱的变化评估了清净性，特别是对于APTES…More处理过的玻璃。基材的润湿性和表面电荷对去污力起重要作用。随着表面活性剂浓度和乙醇浓度的增加，经过aptes处理的玻璃上LB膜的去除率增加。去除率与温度密切相关。将花生酸单层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。通过QCM的频率变化来评价去污力。通过实验确定的接触角和表面自由能，计算出花生酸膜与金表面接触区由于液体层的渗透而产生的自由能变化与去除率有很好的相关性。花生酸经碱皂化作用和渗透作用均有助于脱油。在空气中暴露172nm的UV准分子，然后进行超声波清洗，对去除效果很好。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