【作者】 刘平；

【导师】 李阳；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2009， 博士

【摘要】 本文从分子设计角度,为满足表面活性剂的驱油要求,确定合成疏水链和亲水基固定的联接基团结构不同的Gemini表面活性剂。以1,2-环氧十四烷烃和短碳链二醇为原料,经过开环、硫酸化和中和反应,成功合成了6种纯度高、结构明确的联接基团不同的硫酸盐型Gemini表面活性剂。反应中间体和产物均通过核磁共振氢谱、傅里叶红外光谱、电喷雾质谱等分析手段进行了结构鉴定。用合成的系列硫酸盐型Gemini表面活性剂作为模型化合物,研究其结构与性能的关系。主要研究内容和结论如下:通过测定硫酸盐型Gemini表面活性剂在纯水和一定离子强度水溶液中的表面张力,研究了其在水/空气界面的吸附行为,考察了温度、电解质等因素对吸附行为的影响。通过表面张力随浓度变化的γ-lgC曲线,获得临界胶束浓度(cmc)、临界胶束浓度下的表面张力(γcmc)、降低表面张力的效率(pC20)、最大吸附量(Γmax)和标准吸附自由能0? Gad等物化参数。结果表明,相对于传统表面活性剂,硫酸盐型Gemini表面活性剂具有很好的降低表面张力效率的能力,其cmc在10-5-10-6mol/L数量级,? Ga0d的绝对值很高,表面活性剂分子更易吸附在气/液界面上。联接基团链短的、微弱亲水性(能与水形成氢键)的疏水柔性基团的Gemini表面活性剂的γcmc最小。联接基团的亲水亲油性对表面吸附性质有重要影响。无机盐电解质的加入,中和了亲水基的部分电荷,削弱了吸附层中的静电排斥力,分子间的有序结构得到了加强,使得表面活性剂分子间相互吸引作用增强,表面活性增强。温度的变化会影响胶束的形成,从而改变水溶液的表面性质。测定了联接基团为EO的Gemini表面活性剂的动态表面张力,采用Rosen经验方程分析计算,得到了动态表面张力参数,进一步考察了联接基团不同的Gemini表面活性剂分子在气/液界面的吸附动力学行为。研究结果表明,随着联接基链的增长,t *值增大,n值增大,R1/2值减小,即分子在体相中的扩散减慢,吸附到溶液表面上的能力增强,动态表面活性降低。利用泡沫扫描仪测定了硫酸盐型Gemini表面活性剂的泡沫性能,考察了表面活性剂的分子结构、浓度、温度、以及无机盐电解质、聚合物和脂肪醇添加剂等因素对起泡性能和泡沫稳定性能的影响。实验发现,常温下此类表面活性剂有很好的起泡能力和泡沫稳定性。联接基结构的变化,或者外界条件的改变,本质都是改变了表面活性剂分子在泡沫表面膜上排列的疏密程度,从而影响了泡沫性能。测定了硫酸盐型Gemini表面活性剂与正构烷烃、原油体系的界面张力,考察了表面活性剂浓度、联接基团结构和无机盐对界面张力的影响。界面张力扫描发现,此体系Gemini表面活性剂的最小烷烃数为12,联接基团的结构对其不构成影响;硫酸盐型Gemini表面活性剂具有良好的耐盐性能。T2E1和T2H1有很高的界面活性,与孤岛东区原油体系的界面张力可以达到10-4mN/m。选择T2E1作为驱油用表面活性剂,考察了其在油砂中的静态吸附性能和热稳定性能,岩心驱油实验表明,其提高采收率可达16.3%。更多还原

【Abstract】 In the dissertation,novel six di-n-alkyl diol intermediates were synthesized from 1, 2-epoxytetradecane and short-chain diols through ring-opening, sulfation and neutralization. The chemical structures were characterized by FT-IR, 1H-NMR and ESI-MS methods. As model compounds, the relations of structure and properties of the highly purified anionic gemini surfactants were studied. The main work and conclusions are as following:The surface tensions of anionic Geminis were investigated in aqueous solutions by Wilhelmy plate method, to study the adsorption behavior at the water/air interface, and the effect of temperature and ionic strength to adsorption properties. The values of cmc,γcmc, pC20,Γmax, ? Ga0d were obtained by theγ-lgC curves. It is indicated that the anionic Geminis are three orders of magnitude more surface active than that of their single-chained counterparts, cmc values are lowered by two to three orders of magnitude, and easier adsorbed at the interface. The smallestγcmc values are Geminis with spacer groups of short, slightly hydrophilic (just capable of hydrogen bonding with water) hydrophobic and flexible. The properties of spacer groups are remarkably important to the surface adsorption. Partial charge of the hydrophilic group was neutralized, the repulsive force was weakened, and the intermolecular ordered structure was strengthened because of the addition of sodium chloride. The factor of temperature will influence the formation of micelles, thus the behavior in aqueous solution will be changed.Dynamic surface tensions of anionic Geminis with spacer group of EO units were investigated in aqueous solution. Dynamic surface parameters were obtained by use of Rosen equation. The results show that, the more length of spacer chain, the slower diffusion rate of molecular from bulk phase to surface, the stronger adsorption at aqueous surface, and the lower dynamic surface activity.The foam properties of anionic Geminis in aqueous solutions at different conditions, such as the molecular structure, concentration of Geminis, temperature and different additives (sodium chloride, polymer and aliphatic alcohol, etc.) were measured by the Foamscan. It is found that the anionic Geminis display good foaming performance at room temperature. Essentially, the foam performance is influenced by the molecular arrangement at air/water interface.The interfacial tension between anionic Geminis and n-alkanes, crud oil had been investigated at different conditions, such as the concentration of anionic Geminis, spacer group structure and inorganic salt. The minimum alkyl carbon number (nmin) of anionic Geminis is dodecane by interfacial tension scanning. The structure of spacer group makes no influence to nmin. Anionic Geminis display outstanding salt resistance. The interfacial tensions reduce as the salt concentration and the number of EO units in spacer group increasing. Ultra low interfacial tension could be achieved in water/crude oil system of T2E1 and T2H1. T2E1 was selected as EOR surfactant to study the static adsorption consumption by oil sand and thermal stability. Core flooding experiment shows that enhanced oil recovery is 16.3% (OOIP).更多还原