基于流场-胶束演变特征的表面活性剂微观减阻机理和定量构效关系研究

Surfactant drag reducers are suitable for reducing the turbulent head loss in the circulation pipelines during the geothermal energy development process. However, it is still necessary to clarify the microscopic drag reduction mechanism and quantitative structure-activity relationship of surfactants to improve their drag reduction efficiency. In this project, surfactants with different molecular structure are firstly synthesized by polar head group addition method. Physicochemical parameters such as thermodynamic, surface activity, and drag reduction rate are obtained to provide reliable data for subsequent mathematic modeling. The evolution characteristic of the turbulent flow field in surfactant solution is elucidated by particle imaging velocity (PIV) measurement. Dynamic transformation mechanism of the microscopic information of micelles is revealed by the aggregation quenching fluorescent probe (AQPT) technique. Microscopic drag reduction mechanism of the developed surfactant is clarified by exploring the intrinsic law between the evolution characteristic of turbulent flow field and the dynamic assembly of micelle microstructure. Finally, the quantitative geometry of the surfactants is determined by frequency calculation based on the measured physicochemical parameters. A variety of screening methods, such as regression and randomization, are used to generate the scientific selection mechanism for quantum chemical molecular descriptors. Thus ultimately the three-dimensional quantitative structure-activity relationship (3D-QSAR) models of surfactant drag reducer are established. Specifically, the linear model is used to quantitatively reveal the molecular structure-activity mechanism of surfactant from several aspects like topology, geometry, and energy, etc. In addition, the drag reduction performance of surfactant with a new structure can be predicted by the nonlinear model. This project will deepen the theoretical system of surfactant drag reduction, and thus strengthening the development and application of geothermal water-soluble drag reducer.

表面活性剂类减阻剂适用于降低地热能开发循环管路中的湍流水头损失，但仍需深入明确其微观减阻机理和定量构效关系，以提高其减阻效率。首先选择头基加入法合成不同分子结构的表面活性剂，表征其热力学、表面活性和减阻率等物化参数，为后续建模提供可靠数据。其次借助粒子成像测速手段阐明管路内湍流流场的演变特征，重点利用荧光探针技术揭示胶束微观信息的动态转变机制，探索湍流流场演变特征和胶束微观动态形貌之间的内在作用规律，明确表面活性剂的微观减阻机理。最后依据实测参数，通过频率计算确定表面活性剂的量化几何构型，综合回归型和随机型等筛选方法，重点研究分子描述符的科学选择机制，建立结构-减阻三维定量构效关系模型。采用线性模型从拓扑、几何和能量等层面定量揭示表面活性剂减阻的分子构效机制，通过非线性模型实现对新结构表面活性剂减阻性能的准确预测。以期深化表面活性剂减阻理论体系，夯实地热能高效水溶性减阻剂的研发和应用基础。

本研究首先选择头基加入法合成不同分子结构的表面活性剂，表征热力学、表面活性等物化参数。其次测试了不同分子结构的表面活性剂在光滑管路不同温度下的减阻性能测试，并对溶液的减阻机理进行了猜测和分析。再次利用冷冻电镜实验与分子动力学模拟方法相结合，从实验和模拟两个角度对表面活性剂类减阻剂的减阻微观机理进行了探索。最后形成量化分子描述符的科学选择机制，建立表面活性剂减阻三维定量构效关系模型，拓扑、几何和能量等层面定量揭示表面活性剂减阻的分子构效机制，实现对新结构表面活性剂减阻性能的准确预测。以期深化表面活性剂减阻理论体系，夯实地热能高效水溶性减阻剂的研发和应用基础。