Yan Shu, Jiang Pengfei, Zhang Xinghong, Dai Yitong, Sun Bin, Guo Yongsheng, Fang Wenjun
Department of Chemistry, Zhejiang University, Hangzhou 310058, China; Center of Chemistry for Frontier Technologies, Zhejiang University, Hangzhou 310058, China.
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China; Center of Chemistry for Frontier Technologies, Zhejiang University, Hangzhou 310058, China.
J Colloid Interface Sci. 2025 Jan;677(Pt B):583-596. doi: 10.1016/j.jcis.2024.08.101. Epub 2024 Aug 14.
An innovative strategy for designing high-performance demulsifiers is proposed. It hypothesizes that integrating mesoscopic molecular simulations with macroscopic physicochemical experiments can enhance the understanding and effectiveness of demulsifiers. Specifically, it is suggested that amphiphilic hyperbranched polyethyleneimine (CHPEI) could act as an efficient demulsifier in oil-water systems, with its performance influenced by its adsorption behaviors at the oil-water interface and its ability to disrupt asphaltene-resin aggregates.
Several coarse-grained models of oil-water systems, with CHPEI, are constructed using dissipative particle dynamics (DPD) simulation. Following the insights gained from the simulations, a series of CHPEI-based demulsifiers are designed and synthesized. Demulsification experiments are conducted on both simulated and crude oil emulsions, with the process monitored using laser scanning confocal microscopy. Additionally, adsorption kinetics and small angle X-ray scattering are employed to reveal the inherent structural characteristics of CHPEI demulsifiers.
CHPEI demonstrates over 96.7 % demulsification efficiency in high acid-alkali-salt systems and maintains its performance even after multiple reuse cycles. The simulations and macroscopic experiments collectively elucidate that the effectiveness of a demulsifier is largely dependent on its molecular weight and the balance of hydrophilic and hydrophobic groups. These factors are crucial in providing sufficient interfacial active functional groups while avoiding adsorption sites for other surfactants. Collaborative efforts between DPD simulation and macroscopic measurements deepen the understanding of how demulsifiers can improve oil-water separation efficiency in emulsion treatment.
提出了一种设计高性能破乳剂的创新策略。该策略假设将介观分子模拟与宏观物理化学实验相结合可以增强对破乳剂的理解并提高其有效性。具体而言，有人提出两亲性超支化聚乙烯亚胺（CHPEI）可在油水体系中作为一种高效破乳剂，其性能受其在油水界面的吸附行为及其破坏沥青质 - 树脂聚集体能力的影响。
使用耗散粒子动力学（DPD）模拟构建了几种含有CHPEI的油水体系粗粒化模型。根据模拟获得的见解，设计并合成了一系列基于CHPEI的破乳剂。对模拟乳液和原油乳液进行了破乳实验，使用激光扫描共聚焦显微镜监测该过程。此外，采用吸附动力学和小角X射线散射来揭示CHPEI破乳剂的固有结构特征。
CHPEI在高酸碱盐体系中表现出超过96.7%的破乳效率，并且即使经过多次重复使用循环仍能保持其性能。模拟和宏观实验共同表明，破乳剂的有效性很大程度上取决于其分子量以及亲水和疏水基团的平衡。这些因素对于提供足够数量的界面活性官能团同时避免成为其他表面活性剂的吸附位点至关重要。DPD模拟与宏观测量之间的协同努力加深了对破乳剂如何提高乳液处理中油水分离效率的理解。
