PDMS based microfluidics membrane contactors for CO2 removal applications.

This work proposes a gas-liquid contactor study in microfluidics field, using dense membrane working with a concentration gradient; a microfluidic gas-liquid contactor was developed for CO2 removal and the general idea is to transport CO2 through a polymer dense membrane, followed by its capture by a liquid solvent with chemical absorption. Like recent studies demonstrate, this kind of devices could solve problems related to extracorporeal lung oxygenation (Garofalo, C. Quintavalle, G. Romano, C.M. Croce, 2013) for critical surgical support and critical care medicine, it can work like a real lung because can mimic the architecture of the human vasculature better than the existing technologies. Applications in this fields are related for example to the separation of Xenon from CO2 in anaesthesia. Xe is a very expensive element perfect for anaesthesia, is hemodynamically stable, low soluble in liquid and produces high regional blood flow reducing the risk of hypoxia (Malankowska et al., 2018). The major advantage of using microfluidics devices is that they could be reach a high surface to volume ratio and thanks to miniaturization can be tested reducing the time as well as the production of waste, thus increasing the number of experimental tests can be achieved. In the present thesis in particular one alveolar design channel based of literature results (Malankowska et al., 2018) was realized with soft lithography and tested in different experimental conditions. In particular, for the present geometry the transport of CO2 through the membrane was monitored, calculating the overall mass transfer coefficient and the molar flow of the gas through the membrane in different operating conditions. In additions, the production of other two microfluidics device with different channels configurations was attempted by using a 3-D printing technique that allows the generations of complex structures with high surface to volume ratio.