Abstract The effect of amino acids on improving the corrosion inhibition performance of i-carrageenan through increasing the polymer adhesion to the aluminum surface in 2 M HCl solution was evaluated by using weight loss measurements at temperatures ranging from 25°C to 45°C. The studied amino acids, including Glycine, Alanine, Isoleucine, Serine, and Cysteine, are believed to play an adsorption mediating role to reach a coherent protection layer on the metal surface. The obtained weight loss data are used to calculate the activation parameters of the transition state formation (Ea, and ) to explain the mechanism of inhibition. A thermodynamic insight into the adsorption phenomenon of the inhibitor on the aluminum surface in the presence and absence of amino acids is provided by calculating the standard Gibbs free energy (), enthalpy (), and entropy () of the adsorption process. The results show a significant enhancement in the inhibition efficiency of i-carrageenan in the presence of amino acids. The obtained values are negative and become more negative with the addition of amino acid to the medium. This indicates that the inhibitor adsorption on the metal surface has a spontaneous nature, and this spontaneity increases in the presence of amino acids. It is also found that the adsorption process of i-carrageenan in the presence of amino acids is driven by a change in entropy, whereas it is controlled by changes in both enthalpy and entropy in the absence of amino acids.

中文翻译：

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氨基酸在提高作为天然腐蚀抑制剂的 iota-角叉菜胶对铝表面的粘附作用的热力学和动力学见解

摘要 通过在 25°C 至 45°C 的温度范围内使用重量损失测量来评估氨基酸通过增加聚合物对铝表面的附着力来提高 i-卡拉胶缓蚀性能的效果。研究的氨基酸，包括甘氨酸、丙氨酸、异亮氨酸、丝氨酸和半胱氨酸，被认为起到吸附介导作用，在金属表面形成连贯的保护层。得到的失重数据用于计算过渡态形成的激活参数（Ea, 和 ）来解释抑制机制。通过计算标准吉布斯自由能 ()、焓 ()、和吸附过程的熵 ()。结果显示在氨基酸存在下i-角叉菜胶的抑制效率显着增强。获得的值为负值，并且随着向培养基中添加氨基酸而变得更负值。这表明抑制剂在金属表面的吸附具有自发性，并且这种自发性在氨基酸的存在下增加。还发现在氨基酸存在下 i-角叉菜胶的吸附过程是由熵的变化驱动的，而在没有氨基酸的情况下，它受焓和熵的变化控制。获得的值为负值，并且随着向培养基中添加氨基酸而变得更负值。这表明抑制剂在金属表面的吸附具有自发性，并且这种自发性在氨基酸的存在下增加。还发现在氨基酸存在下 i-角叉菜胶的吸附过程是由熵的变化驱动的，而在没有氨基酸的情况下，它受焓和熵的变化控制。获得的值为负值，并且随着向培养基中添加氨基酸而变得更负值。这表明抑制剂在金属表面的吸附具有自发性，并且这种自发性在氨基酸的存在下增加。还发现在氨基酸存在下 i-角叉菜胶的吸附过程是由熵的变化驱动的，而在没有氨基酸的情况下，它受焓和熵的变化控制。