标题： 解锁表面活性剂协同效应用于氟的替代：乳液稳定性和聚并动力学的微流体研究 显示英文标题

标题： Unlocking Surfactant Synergies for Fluorine Replacements: A Microfluidic Exploration of Emulsion Stability and Coalescence Dynamics

摘要： 氟化表面活性剂被广泛应用于各种领域，包括灭火泡沫、涂层和润滑剂。 它们的广泛应用是由于其独特的性质，例如有效降低表面/界面张力的能力。 然而，氟化表面活性剂的过量使用由于其在环境中的持久性和潜在毒性而引发了环境和健康问题。 因此，迫切需要有效且可持续的表面活性剂替代品。 我们的研究调查了已被提出用于复制传统氟化表面活性剂性能的替代表面活性剂混合物，同时尽量减少环境影响。 在此，我们研究了水包油乳液中发现的薄水液桥的稳定性，这些表面活性剂混合物已被证明在无氟灭火泡沫中提供协同灭火效果。 除了二元表面活性剂-水溶液 TritonX-100、Glucopon 215、Dow 502W 外，还使用了三元表面活性剂-表面活性剂-水混合物 Glucopon 215 和 Dow502W。 通过设计用于测量聚并频率的微流体装置来评估乳液的稳定性。 聚并频率作为总流量和表面活性剂浓度的函数进行测量。 发现所有使用的表面活性剂的聚并频率与流量呈非单调趋势。 此外，引入了一个无量纲频率，并发现该频率随着毛细管数的增加而减小。 发现表面活性剂混合物的聚并频率接近 Dow502W，表明 Glucopon215 和 Dow502W 之间存在协同作用，即使配方中硅氧烷表面活性剂的含量较少。 这种行为突显了将较慢的碳氢化合物表面活性剂与较快的硅氧烷表面活性剂结合的潜力，以实现一种有效的无氟配方稳定剂。 显示英文摘要

摘要： Fluorinated surfactants are widely utilized in various applications, including firefighting foams, coatings, and lubricants. Their wide utility is due to their unique properties, such as their ability to effectively lower surface/interfacial tension. However, the excessive use of fluorinated surfactants has raised environmental and health concerns due to their persistence in the environment and potential toxicity. The need for effective and sustainable surfactant replacements has therefore become critical. Our study investigates alternative surfactants mixtures that have been proposed to replicate the performance of traditional fluorinated surfactants, while minimizing environmental impact. Here, we study the stability of thin aqueous liquid bridges found in water in oil emulsions, with surfactant mixtures shown to provide synergistic fire suppression in fluorine-free fire fighting foams. Binary surfactant-water solutions of TritonX-100, Glucopon 215, Dow 502W were used, in addition to a ternary surfactant-surfactant-water mixtures of Glucopon 215 and Dow502W. Emulsion stability is assessed using a microfluidic device designed to measure the coalescence frequency. Coalescence frequency is measured as a function of total flow rate and surfactant concentration. A non-monotonic trend of coalescence frequency with flow rate is found for all the surfactants used. In addition, a non-dimensional frequency is introduced and is found to decrease with the Capillary number. The coalescence frequency of the surfactant mixture is found to be close to that of Dow502W, suggesting a synergistic behavior between Glucopon215 and Dow502W, even with less of the siloxane surfactant present in the formulation. This behavior highlights the potential for pairing slower hydrocarbon surfactants with faster siloxane surfactants to achieve an effective alternative stabilizing agent for fluorine free formulation.