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The present work presents a fast and simple new experimental method, designed to enhance the observation and characterization of thermal phenomena at microscale. Supercooling of water was carried out in micro-channels and recorded with a high-frequency infrared camera. The method is based on the coupling of microfluidics, infrared thermography, and inverse techniques. The objective is to extract a maximum of information from the experiment to perform advanced characterization of the system. First, a thermal modeling of such a system was written, then the image processing from infrared recordings allowed estimating the thermal properties (diffusivity) and the source term (energy released by the phase change). The novelty of the approach is the ability of measuring the heat released by the phase change and using this displacement to calculate the ice front propagation velocity and thermal properties. This method is appropriate for many other applications and is mainly devoted to the characterization of fluids during phase change at microscale. [ABSTRACT FROM AUTHOR]

Thanks to infrared thermography, we have studied the mechanisms of CO2 capture by solid adsorbents (CO2 capture via gas adsorption on various types of porous substrates) to better understand the physico-chemical mechanisms that control C02-surface interactions. In order to develop in the future an efficient process for post-combustion CO2 capture, it is necessary to quantify the energy of adsorption of the gas on the adsorbent (exothermic process). The released heat (heat of adsorption) is a key parameter for the choice of materials and for the design of capture processes. Infrared thermography is used, at first approach, to detect the temperature fields on a thin-layer of adsorbent during CO2 adsorption. An analytical heat transfer model was developed to evaluate the adsorption heat flux and to estimate, via an inverse technique, the heat of adsorption. The main originality of our method is to estimate heat losses directly from the heat generated during the adsorption process. Then, the estimated heat loss is taken for an a posteriori calculation of the adsorption heat flux. Finally, the heat of adsorption may be estimated. The interest in using infrared thermography is also its ability to quickly change the experimental setup, for example, to switch from the adsorbent thin-layer to the adsorbent bed configuration. We present the first results tempting to link the thin-layer data to the propagation speed of the thermal front in a millifluidics adsorption bed, also observed by IR thermography. [ABSTRACT FROM AUTHOR]