Understanding the origin of the dissipative mechanisms that control the dynamics of a contact line is a real challenge. In order to study the energy dissipation at the contact line when a moving meniscus encounters topographical defects, we developed atomic force microscopy (AFM) experiments using nanofibers with nanometer scale defects. These experiments realized with three liquids are performed in two AFM modes: the contact mode (C-AFM) is used to measure the energy associated with the contact angle hysteresis in the limit of a static situation, deduced from advancing and receding dipping experiments on an isolated defect; the frequency-modulation mode (FM-AFM) is performed at different amplitudes and then velocities to measure the energy dissipated as the contact line moves over the same defect.
View Article and Find Full Text PDFIn this paper, we study the interaction of a contact line with molecules physically adsorbed on a surface. We developed specific atomic force microscopy (AFM) experiments where a nanoneedle attached at the extremity of the cantilever is dipped in a liquid droplet. The motion of the contact line at the extremity of the meniscus formed depends on the presence of topographical and chemical defects at the surface of the nanoneedle.
View Article and Find Full Text PDFThe interaction of the contact line with topographical or chemical defects at the nanometer scale sets the macroscopic wetting properties of a liquid on a solid substrate. Based on specific atomic force microscopy (AFM) experiments, we demonstrate that molecules physically sorbed on a surface are removed by a dynamic contact line. The mechanism of molecules desorption is directly determined by the capillary force exerted at the contact line on the molecules.
View Article and Find Full Text PDFInt J Numer Method Biomed Eng
September 2019
The spatial distributions of cytochrome P450 (CYP450) and glutathione (GSH) in liver lobules determine the heterogeneous hepatotoxicity of acetaminophen (APAP). Their interplay in conjunction with blood flow is not well understood. In this paper, we integrate a cellular APAP metabolism model with a sinusoidal blood flow to simulate the temporal-spatial patterns of APAP-induced hepatotoxicity.
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