Phthalate esters which are widely used as industrial chemicals have become widespread contaminants in the marine environment. However, little information is available on the interfacial behavior of phthalate esters in the seawater, where contaminants generally occur at elevated concentrations and have the potential to transfer into the atmosphere through wave breaking on sea surface. We used artificial seawater coated with fatty acids to simulate sea surface microlayer in a Langmuir trough. The interactions of saturated fatty acids (stearic acid (SA) and palmitic acid (PA)) with one of the most abundant phthalate esters (di-(2-ethylhexyl) phthalate (DEHP)), were investigated under artificial seawater and pure water conditions. Pure DEHP monolayer was not stable, while more stable mixed monolayers were formed by SA and DEHP on the artificial seawater at relatively low surface pressure. Sea salts in the subphase can lower the excess Gibbs free energy to form more stable mixed monolayer. Among the ten components in the sea salts, Ca²⁺ ions played the major role in condensation of mixed monolayer. The condensed characteristic of the mixed SA (or PA)/DEHP monolayers suggested that the hydrocarbon chains were ordered on artificial seawater. By means of infrared reflection-absorption spectroscopy (IRRAS), we found that multiple sea salt mixtures induced deprotonated forms of fatty acids at the air–water interface. Sea salts can improve the stability and lifetime of mixed fatty acid and phthalate ester monolayer on aqueous droplets in the atmosphere. Interfacial properties of mixed fatty acid and phthalate ester monolayers at the air–ocean interface are important to help understand their behavior and fate in the marine environment.

广泛用作工业化学品的邻苯二甲酸酯已成为海洋环境中广泛的污染物。然而，关于邻苯二甲酸酯在海水中的界面行为的信息很少，那里的污染物通常以升高的浓度出现，并有可能通过海面的波涛传播而转移到大气中。我们使用了涂覆有脂肪酸的人造海水来模拟海面微层在Langmuir槽中。在人工海水和纯水条件下，研究了饱和脂肪酸（硬脂酸（SA）和棕榈酸（PA））与最丰富的邻苯二甲酸酯之一（邻苯二甲酸二（2-乙基己基）酯）的相互作用。 。纯DEHP单层不稳定，而SA和DEHP在相对较低的表面压力下在人造海水上形成了更稳定的混合单层。亚相中的海盐可以降低多余的吉布斯自由能，从而形成更稳定的混合单层。在海盐的十种成分中，Ca ²⁺离子在混合单层的缩合中起主要作用。SA（或PA）/ DEHP混合单层的冷凝特征表明，碳氢化合物在人造海水上订购了链条。通过红外反射吸收光谱法（IRRAS），我们发现多种海盐混合物在空气-水界面处诱导了去质子化的脂肪酸形式。海盐可以改善大气中水滴上混合脂肪酸和邻苯二甲酸酯单层的稳定性和寿命。脂肪酸与邻苯二甲酸酯混合物单层在空气-海洋界面的界面特性对于帮助理解它们在海洋环境中的行为和命运非常重要。