Measurements of dilatational rheology of an insoluble lung surfactant using an oscillatory interfacial dialator

Abstract

December 2024School of EngineeringThis research investigates the interfacial rheology of a DPPC monolayer, the main phospholipid in lung surfactants, within a model lung flow apparatus, oscillatory interface dilator, OID. The study primarily measures interfacial velocity to explore how surfactant concentration and phase influence the behavior of a dilating monolayer, particularly regarding Marangoni flow and surface viscosity. A particle tracking velocimetry, PTV, code was utilized to capture velocity distributions across the interface. Temporal and spatial analyses revealed minimal variations in global surface measurements, highlighting the need for finely resolved data to capture subtle changes. Observations identified increased velocity variation during the compression cycle and heightened sensitivity at the cavity center with higher DPPC concentrations. Preliminary computational modeling was performed for comparative purposes, revealing limitations in simulating realistic dynamic contact angles. This study advances the understanding of surfactant dynamics at the air-liquid interface, with implications for respiratory function modeling in health and disease.M