阴离子型油响应蠕虫状胶束的构建及流变性能研究

Oil-responsive wormlike micelles, the viscosity of which can be tuned by the oil concentration, have a great potential in oil recovery. To our best knowledge, the researches on oil-responsive wormlike micelles are mainly on nonionic surfactant systems while the poor thermal stability limits their application. However, the oil-responsive wormlike micelles with high thermal stability can be constructed by the anionic surfactants. The sulfonate anionic Gemini surfactants with different hydrophobic chains and spacers would be designed and synthesized. And the interface properties and aggregation behaviors of Gemini surfactants would be studied. Then, the oil responsive wormlike micelles would be constructed by those surfactants with the addition of oil, the rheological properties and mechanisms of which would also be explored. What’s more, the effects of environmental conditions, such as pH values, inorganic salts, and temperature, on the rheological properties of wormlike micelles, would be further studied. It is expected that multiple responsive wormlike micelles should be constructed by sulfonate anionic Gemini surfactants. This research would be an important supplement to the formation and properties of anionic surfactant wormlike micelles and have a potential application in oil recovery..

油响应型蠕虫状胶束可通过地层含油饱和度的不同来控制体系粘度，进行选择性封堵，在石油开采上有重要的应用潜力。目前，构建油响应体系多选用非离子表面活性剂，耐温性能较差，限制了其在采油中的应用。为突破这一限制，本项目拟采用耐温性能好的磺酸盐双子表面活性剂，利用其结构可设计性，合成疏水链和间隔基性质等结构参数不同的表面活性剂，获得聚集体结构和流变性质对烷烃浓度变化具有响应的体系。通过透射电镜、小角X-ray散射研究微观结构演变过程，采用流变学揭示分子结构与油响应体系流变性能间的构效关系，并结合和频振动光谱对不同烷烃浓度时表面活性剂分子构型变化的研究，探索磺酸盐双子表面活性剂构建油响应蠕虫状胶束体系的必要条件和作用机理。考察pH、温度和无机盐浓度等对体系微观结构、流变性质和油响应行为的影响，并构建具有多重响应的粘弹体系。该项目为磺酸盐油响应蠕虫状胶束在油田开采中的应用提供了理论依据和实验基础。

通过酸碱中和法一步合成了含偶氮基团的羧酸盐阴离子表面活性剂，并通过性能测试筛选出具有较高表面活性的脂肪醇聚氧乙烯醚-阴离子表面活性剂、两亲改性聚丙烯酰胺、以及植物甾醇聚氧乙烯醚类非离子表面活性剂等体系。研究了分子结构的变化对脂肪醇聚氧乙烯醚-阴离子表面活性剂水溶液中聚集行为的影响；发现偶氮类羧酸盐表面活性剂(AzoAH)+/(OAc)−的聚集体结构对pH和溶剂极性改变具有一定响应性，分析了其响应机理；将两亲改性聚丙烯酰胺与十二烷基硫酸钠、油田二元复合驱等多个体系进行复配，发现其与二元复合驱体系的组成的复配体系，其对十六烷烃具有一定的响应性，随着油相的加入，体系粘度呈现先降低后升高的趋势，并在油相体积分数为30%时达到最小值。此外，研究了表面活性剂在低共熔溶剂的聚集行为，发现DES可作为离子液体、水、甲酰胺等溶剂的替代物，是一类可用于构建表面活性剂有序聚集体的新型溶剂，与水体系中形成球形胶束不同，表面活性剂在DES中形成的胶束多为椭球形，具有构建非水体系蠕虫状胶束的潜力。该项目的执行为阴离子表面活性剂体系在油田开采中的应用提供了理论依据和实验基础。