Fabricación de estructuras porosas nanoestructuradas para aplicaciones optofluídicas

LUISA CENCHA; RAUL URTEAGA; ROBERTO ARCE

Santa Fe

Simposio; 14° SAM-CONAMET / IBEROMAT 2014 - XIII SIMPOSIO MATERIA.; 2014

Nanostructured porous materials provide attractive functionalities to be employed in fundamental studies and new applications like biological or chemicaldetection. Through interferometric techniques it?s possible to measure the income of a fluid within these porous materials and obtain information about the way a fluid get into a membrane. This allows the determination of the liquid interphase position for different samples.Through an electrochemical anodization process is possible fabricates porous silicon membranes (PS) with a specific optical response, this is because a current profile results in a porosity profile in the material. Similarly, it is also possible to obtain membranes of porous alumina (PA) with a given optical response.In this paper the results of the study of capillary filling in PS samples are presented. The research field is extended to transversal capillary filling, ie in the cross direction to the longitudinal axis of the pores. This is of great interest owing to the high tortuosity presented in this way to a fluid, and this is a highly desirable feature to use the SP in conjunction with interferometric techniques to develop characterization techniques or chromatographic detection in a very small space.The wet dynamics experimentally obtained is adjusted to a simple model (Washburn) where the position of the meniscus moves proportionally to the root of time.Besides, the estimates obtained of a characteristic parameter (relation between hydraulic radius and tortuosity squared) of these membranes are consistent withthe morphology observed in SEM micrographs.Preliminary results of the AP sample preparation for further transversal capillary filling are also presented. The development of an optofluidic characterization method allowed to determine the utility of a technique for preparing the membranes for subsequent capillary filling.