?Silica-gel Absortion characterization by a laser speckle technique?.

. C. I. CABELLO, G. BERTOLINI, S. AMAYA, R. ARIZAGA, M. TRIVI

Guanajuato

Congreso; III International Sol-Gel Science and Technology Congress y VI Congreso Nacional de Materiales Sol-Gel; 2006

When a laser beam illuminates a rough surface of an object, a typical speckle pattern[1] is observed. (See Fig. 1). If the surface of the objects presents any kind of local movement, then the observed speckle evolves in time. This dynamic speckle is characteristic of biological samples and can also be observed in non-biological industrial processes, including the drying of paint, corrosion and heat exchange, etc. The temporary evolution of speckle patterns is correlated with the ?activity? of the sample and may provide an interesting tool to characterize the parameters involved in these processes. The present work shows a preliminary result of a dynamic speckle application to the study of commercial silica-gel with different textural properties, i.e. grain size, surface area and pore volume. The experimental results show the temporary evolution of the speckle patterns from the samples according to their different water absorption processes.