Nieto-Alvarez David Aaron, Zamudio-Rivera Luis S, Luna-Rojero Erick E, Rodríguez-Otamendi Dinora I, Marín-León Adlaí, Hernández-Altamirano Raúl, Mena-Cervantes Violeta Y, Chávez-Miyauchi Tomás Eduardo
Grupo de Química Aplicada a la Industria Petrolera, ‡Dirección Regional Marina, §Programa de Ingeniería Molecular, and ∥Programa de Recuperación de Hidrocarburos, Instituto Mexicano del Petróleo , Eje Central Lázaro Cárdenas 152, Colonia San Bartolo Atepehuacan, Mexico City 07730, Mexico.
Langmuir. 2014 Oct 21;30(41):12243-9. doi: 10.1021/la501945t. Epub 2014 Oct 6.
Herein is presented a new methodology to determine the static adsorption of a zwitterionic surfactant on limestone in three different aqueous media [high-performance liquid chromatography (HPLC) water, seawater, and connate water] with the use of HPLC at room temperature and 70 °C. The results showed that, in both HPLC water and seawater, the surfactant adsorption followed a monolayer Langmuir tendency. In contrast, for connate water, the surfactant presented a new adsorption profile, characterized by two regions: (i) At surfactant concentrations below 1500 mg L(-1), an increase of adsorption is observed as the amount of divalent cations increases in the aqueous media. (ii) At surfactant concentrations above 1500 mg L(-1), the adsorption decreases because the equilibrium, monomer ⇆ micelle ⇆ vesicle, is shifted to the formation of vesicles, giving as a result a decrease in the concentration of monomers, thus reducing the interaction between the surfactant and the rock, and therefore, lower adsorption values were obtained. The behavior of the surfactant adsorption under different concentrations of divalent cations was well-described by the use of a new modified Langmuir model: (dΓ/dt)ads = k(ads)c(Γ∞ - Γ) - k(cmc)(c - c(cmc))(n)ΓH(c - c(cmc)). It was also observed that, as the temperature increases, the adsorption is reduced because of the exothermic nature of the adsorption processes.
本文介绍了一种新方法，可在室温及70°C条件下，使用高效液相色谱（HPLC）测定两性离子表面活性剂在三种不同水介质（高效液相色谱用水、海水和原生水）中对石灰石的静态吸附。结果表明，在高效液相色谱用水和海水中，表面活性剂吸附遵循单层朗缪尔趋势。相比之下，对于原生水，表面活性剂呈现出一种新的吸附曲线，其特征在于两个区域：（i）在表面活性剂浓度低于1500 mg L⁻¹时，随着水介质中二价阳离子量的增加，吸附量增加。（ii）在表面活性剂浓度高于1500 mg L⁻¹时，吸附量降低，因为平衡（单体⇆胶束⇆囊泡）向囊泡形成方向移动，结果导致单体浓度降低，从而减少了表面活性剂与岩石之间的相互作用，因此获得较低的吸附值。通过使用一种新的修正朗缪尔模型（dΓ/dt）ads = k(ads)c(Γ∞ - Γ) - k(cmc)(c - c(cmc))ⁿΓH(c - c(cmc))，可以很好地描述表面活性剂在不同二价阳离子浓度下的吸附行为。还观察到，随着温度升高，由于吸附过程的放热性质，吸附量降低。
