IFIS - LITORAL   24734
INSTITUTO DE FISICA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Filling dynamics of polymeric fluids in periodic nanoporous structures
Autor/es:
FERNANDA GUADALUPE GARCÍA; BERLI, CLAUDIO L. A.; RAÚL URTEAGA
Lugar:
Córdoba
Reunión:
Congreso; II Brazil - Argentine Microfluidics Congress V Congreso de Microfluídica Argentina; 2019
Resumen:
Understanding the dynamics of capillary filling in nanoconfined geometries is crucial in the field of nanotechnology, where applications goes from basic studies on transport in porous nanomaterials to the development of novel nanofluidic devices. In the latter case, the possibility of manufacturing a sequence of periodic layers of different porosity allows one to modulate the optical properties of the material. In this way, a specific optical response can be used to create mirrors, filters, or resonant cavities. The capillary filling of these structures modifies the optical properties of the material and can be used to program a specific change in the optical response of these materials. On the other hand, the filling dynamics of polymers shows very interesting behaviors when they are strongly confined by the porous matrix [1,2], as non-Newtonian effects couple to the (already interesting) fluid dynamic features of simple fluids in nanopore structures [3]. In this work, a capillary filling model of periodical porous matrix is presented (see the figure; left panel). Periodic variations of both the porosity and the pore size were considered. The influences of pore size, layer lengths, and effective fluid viscosity on the transport coefficients were investigated following the model predictions (see the figure; left panel). Validation experiments were performed using periodic layers of nanoporous silicon. Capillary filling of Ethylene-vinyl-acetate was studied at different temperatures. The imbibition dynamics of the polymer was determined by reflectance spectrometry [2]. The experimental results are consistent with the predictions of the model in a wide temperature range and allow obtaining information on the behavior of the polymer under high confinement conditions.