In this research, molecular dynamics simulation is used to provide a molecular-scale insight into the working mechanisms of the silica nanoparticles in oil detachment from carbonate surface in absence and presence of ionic compounds. The oil model comprises of heptane, decane and toluene mixture. The contents of aqueous phase are variated in different cases: (I) water, (II) water and ions of Na⁺, Cl⁻, Mg²⁺and SO₄²⁻, (III) water and silica nanoparticles and (IV) water, silica nanoparticles and individual ions. In each simulation, an oil layer with a thickness of 15°A were placed between the calcite surface and the water phase to cut the interactions between calcite surface and oil phase and form an oil-wet surface. According to the results, in the absence of nanoparticles, the aqueous layer could not change the conformation of the oil layer. However, in presence of nanoparticles, water molecules could diffuse into the oil phase and move toward calcite surface. Contact angle measurement showed oil contact angle reaching to 112.5° and 120.5° for the systems of (III) and (IV), respectively. Radial distribution function calculation showed more nanoparticles approaching the calcite surface in the presence of ions yielding to more detachment of the oil molecules and also the Na⁺ and Cl⁻ ions more effects than Mg²⁺ and SO₄²⁻.

在这项研究中，使用分子动力学模拟来提供分子尺度的洞察力，以了解在不存在和存在离子化合物的情况下，二氧化硅纳米颗粒在油与碳酸盐表面的分离中的作用机理。该油模型包括庚烷，癸烷和甲苯混合物。水相的内容被variated在不同的情况：（I）的水，（II）水和Na的离子⁺，氯^- ，镁²⁺和SO ₄ ^2-，（III）和水的二氧化硅纳米粒子和（IV）的水，二氧化硅纳米粒子和各个离子。在每个模拟中，油层的厚度为15 °A将其置于方解石表面和水相之间，以切断方解石表面与油相之间的相互作用，并形成一个油湿表面。根据结果​​，在没有纳米颗粒的情况下，水层不能改变油层的构象。但是，在存在纳米粒子的情况下，水分子可能扩散到油相中并向方解石表面移动。接触角测量显示，对于（III）和（IV）的系统，油接触角分别达到112.5°和120.5°。径向分布函数计算表现出更多的纳米粒子中的离子产生的油分子和也中的Na的更多分离的存在接近方解石表面⁺和Cl ^-离子除Mg的效果更²⁺和SO₄ ²⁻。