表面活性剂对磁性微米颗粒穿越液液界面的影响OA

This study employed high-speed camera technology to observe the kinetic behaviour of micrometre-sized Fe3O4 particles traversing the oil-water interface under the influence of a non-uniform magnetic field.The experimental results show that the mass fraction of Span 80 surfactant alters interfacial properties(interfacial tension,viscosity,and oil-water-solid contact angle).As Span 80 mass fraction increases,the Ohnesorge number(Oh)rises while the magnetic Bond number(Bom)decreases.Particles exhibit five distinct motion modes at the interface:encapsulation and detachment,interfacial jet formation,cluster ejection,suspension ejection,and steady-state stretching.At low mass fractions(＜0.42%),the Marangoni effect predominates,enveloping particles within the oil phase to form magnetic emulsions;near the critical micelle concentration(≈0.42%),particle aggregation intensifies,enabling them to overcome the interfacial energy barrier and traverse the interface;at high mass fractions(＞0.63%),liquid column necking is suppressed,with only deformation occurring.This study systematically reveals the mechanism by which surfactant mass fraction influences particle distribution and interfacial mechanical response through regulation of the Oh and Bom,providing theoretical foundations for the application of magnetic particles in multiphase flow and interfacial manipulation.