Preparation of porous materials using phase inversion approach

The aim of this PhD project is a study of preparation of porous (bio)polymeric materials with well-defined microstructure of pores suitable for various applications, such as membrane separations or scaffolds in tissue engineering. Principal method used for the fabrication of porous materials explored in this project is the phase inversion, which consists of several steps: (i) formation of homogeneous solvent-polymer mixture, (ii) externally induced change in system Gibbs free energy of mixing leading to phase separation, (iii) removal of the solvent from the “frozen” porous polymer matrix. The alteration in Gibbs free energy of mixing can be done in various ways, for instance by addition of immiscible species (nonsolvent) to the system (nonsolvent induced phase separation, NIPS), or by rapid decrease of thermal energy (thermally induced phase separation, TIPS). This work will focus on testing both NIPS and TIPS, as well as their combination (N-TIPS). As a primary experimental project, it involves screening for suitable polymer-solvent(-nonsolvent) combinations (considering also potential biocompatibility of the prepared tissue scaffold), thermodynamic characterization of the system (including its theoretical description), construction of the apparatus for material fabrication, preparation of the porous material and characterization of its morphology and technical properties (e.g. separation performance, dynamics of biodegradation, mechanical properties). There are two ultimate goals of this project: (i) experimental mapping between the phase separation physical conditions and final morphology of the prepared material, and (ii) process scale-up proposition, and optimisation of the material production method, including solvent removal. The project will therefore contribute to the understanding of hetero-phase material morphogenesis during phase separation process, and will offer new classes of materials suitable for real life applications. The student will work with both traditional polymers and with newly emerging biodegradable materials, and will get opportunity to use state-of-the-art methods of morphological characterization, including scanning electron microscopy (SEM), atomic force microscopy (AFM), 3D computed micro-tomography (CT), confocal Raman microscopy and others. The project will be carried out in close cooperation with Czech company MemBrain, Central European Institute of Technology (CEITEC), and Process Engineering for Sustainable Systems Section of Katholieke Universiteit Leuven (KU Leuven).