In Situ Visualization of Polymerization-Induced Phase Separation for 3D-Printing of Porous Architectures

Phase separation of polymer solutions is a preferred mechanism for the formation of porous polymer structures. Among different types of phase separation, polymerization-induced phase separation (PIPS) has gained significant momentum as it can be implemented in 3D-printing processes of intricate porous architectures. However, for many materials, the influence of the composition of the resin on the final porosity and tortuosity of the fabricated parts is not fully understood. Traditional screening techniques, such as porometry or electron microscopy, are time-consuming and offer only limited insights into material characteristics. In this work, we propose a microfluidic fluorescence microscopy technique that enables the in situ investigation of PIPS and enables the understanding of kinetic phase separation phenomena related to the final porous morphology.