Characterization of heterogeneous fluid-fluid interfaces via microrheology
Date
2022-09
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Abstract
Two-point microrheology was applied to a homogeneous (DPPC monolayers) and a heterogeneous (biofilms) interface of physiological relevance. For DPPC monolayers, both the longitudinal and transverse correlated motions showed a purely diffusional regime at different surface pressures. A good agreement between the single particle and two particle mean square displacements was observed. For biofilms of Pseudomonas aeruginosa at air-water interface, a transition from viscous to elastic regime was observed as the interface aged. The thermal cross-correlations of particles showed a strong scattering over the particle distances confirming the heterogeneity of the biofilms at air-water interface. This heterogeneity was also reflected in the mean square displacements where discrepancies are observed between results from one particle and two particle microrheology. Choosing one single particle as reference, a map of the spatial heterogeneity of biofilms was developed. The novel methodology provide insights into local micromechanics of complex interfaces that is not accessible with classical interfacial rheometry.
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Keywords
microrheology, DPPC, P. aeruginosa, interfaces, interfacial rheology
Citation
Roy, T. (2022). Characterization of heterogeneous fluid-fluid interfaces via microrheology (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.