Abstract The static adsorption of Duomeen TTM (DTTM, C16-18N(CH3)C3N(CH3)2), a switchable surfactant, is investigated as a function of mineral type, pH, salinity, temperature, and concentration. At approximately neutral pH, DTTM is protonated, becoming positively charged, and exhibits low adsorption on pure calcite. However, relatively high adsorption of DTTM is observed on natural carbonate, silica, and kaolin due to the presence of negatively charged siliceous minerals, indicating that the mineral type is a predominant factor in DTTM adsorption. Lower DTTM adsorption is detected due to increased NaCl salinity or the presence of multivalent ions (Mg2+, Ca2+, Cr3+). We also discuss how adjusting the solution pH affects a novel competitive adsorption mechanism between the DTTM protonation degree and surface charge change. Increases in temperature lead to a decrease in DTTM adsorption on silica and dolomite. Interestingly, DTTM tends to have higher adsorption at elevated temperatures. Additionally, DTTM can associate into higher-order assemblies at high concentrations, which in turn increases its adsorption due to the crosslinked structure.

中文翻译：

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高盐度碳酸盐岩油藏天然和合成矿物上可切换二胺表面活性剂的静态吸附

摘要 Duomeen TTM (DTTM, C16-18N(CH3)C3N(CH3)2) 是一种可转换的表面活性剂，其静态吸附被研究为矿物类型、pH、盐度、温度和浓度的函数。在接近中性的 pH 值下，DTTM 被质子化，带正电，并且在纯方解石上表现出低吸附。然而，由于存在带负电荷的硅质矿物，在天然碳酸盐、二氧化硅和高岭土上观察到相对较高的 DTTM 吸附，表明矿物类型是 DTTM 吸附的主要因素。由于 NaCl 盐度增加或多价离子（Mg2+、Ca2+、Cr3+）的存在，检测到较低的 DTTM 吸附。我们还讨论了调节溶液 pH 值如何影响 DTTM 质子化度和表面电荷变化之间的新型竞争吸附机制。温度升高导致 DTTM 在二氧化硅和白云石上的吸附减少。有趣的是，DTTM 在升高的温度下往往具有更高的吸附性。此外，DTTM 可以在高浓度下结合成高阶组装体，由于交联结构，这反过来增加了其吸附。