Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim, Norway.
Aix Marseille Université, CNRS, MADIREL UMR 7246, 13397 Marseille cedex 20, France.
Langmuir. 2016 Jul 26;32(29):7294-305. doi: 10.1021/acs.langmuir.6b00816. Epub 2016 Jul 11.
The adsorption of an acidic polyaromatic asphaltene model compound (C5PeC11) and indigenous C6-asphaltenes onto the liquid-solid surface is studied. Model compound C5PeC11 exhibits a similar type of adsorption with a plateau adsorbed amount as C6-asphaltenes onto three surfaces (silica, calcite, and stainless steel). Model compound BisAC11, with aliphatic end groups and no acidic functionality, does not adsorb at the liquid-silica surface, indicating the importance of polar interactions on adsorption. The values of the adsorption enthalpy characterized by the ΔHz parameter (the enthalpy at zero coverage) indicate that the type of adsorption and the driving force depend on the surface, a key feature when discussing asphaltene deposition. The adsorption of C5PeC11 onto silica is shown to be driven primarily by H bonding (ΔHz = -34.9 kJ/mol), unlike adsorption onto calcite where polar van der Waals and acidic/basic interactions are thought to be predominant (ΔHz = -23.5 kJ/mol). Interactions between C5PeC11 and stainless steel are found to be weak (ΔHz = -7.7 kJ/mol). Comparing C6-asphaltenes and their esterified counterpart shows that adsorption at the liquid-solid surface is not influenced by the formation of H bonds. This was evidenced by the similar adsorbed amounts obtained. Finally, C5PeC11 captures, to a certain extent, the adsorption interactions of asphaltenes present at the calcite-oil and stainless steel-oil surfaces.
研究了一种酸性稠环芳烃沥青质模型化合物（C5PeC11）和本地产 C6-沥青质在固-液表面上的吸附行为。模型化合物 C5PeC11 在三种表面（二氧化硅、方解石和不锈钢）上的吸附量与 C6-沥青质相似，呈现出类似的平台吸附。具有脂肪族端基且没有酸性官能团的模型化合物 BisAC11 不会在固-液-硅表面上吸附，这表明极性相互作用对吸附很重要。通过 ΔHz 参数（零覆盖时的焓）表征的吸附焓值表明，吸附类型和驱动力取决于表面，这是讨论沥青质沉积时的一个关键特征。C5PeC11 在二氧化硅上的吸附主要由氢键驱动（ΔHz = -34.9 kJ/mol），而在方解石上的吸附则被认为是由极性范德华力和酸性/碱性相互作用驱动（ΔHz = -23.5 kJ/mol）。C5PeC11 与不锈钢之间的相互作用较弱（ΔHz = -7.7 kJ/mol）。将 C6-沥青质与其酯化产物进行比较表明，在固-液表面的吸附不受氢键形成的影响。这可以从获得的相似吸附量得到证明。最后，C5PeC11 在一定程度上捕获了存在于方解石-油和不锈钢-油表面的沥青质的吸附相互作用。
