大气压等离子体射流诱导生物溶液中液体流动的可视化分析研究

Abstract

The influence of atmospheric pressure plasma jet (APPJ) on liquid flow in biological solution was investigated. Gelatin biomolecules were dissolved in deionized (DI) water to simulate a biological solution, and the resulting liquid flow was visualized and quantitatively analyzed during APPJ treatment. For gelatin solutions, the dominant liquid flow regime during APPJ treatment is vertical downward flow. A vortex flow regime emerges only under conditions of low gelatin concentration and high APPJ working gas flow rate; however, this vortex flow contracts and dissipates with prolonged APPJ treatment. In the case of low gelatin concentration solution, the Marangoni effect is a potential contributing factor for the downward flow regime in gelatin solutions, whereas gas shear stress and electrohydrodynamic (EHD) forces induce vortex flow formation. In vortex flow regimes, the Marangoni effect dynamically competes with the combined action of shear stress and EHD forces. Concurrently, cross-linking reactions between APPJ and gelatin increase the dynamic viscosity of the solution, accelerating kinetic energy dissipation. In the case of high gelatin concentration solution, the formation of a surface cross-linked film impedes momentum transfer across the plasma-liquid interface, and the rapid relaxation of interfacial charges resulted that the EHD effect generates a downward force, thereby establishing downward flow as the dominant mechanism.