High Performance Thin Film Nanofibrous Composite Membrane for Organic Solvent Nanofiltration

Promovendus/a: Yi Li

Promotor(en): Prof. dr. ir. Bart Van der Bruggen

Solvent recovery and molecular separation are commonly involved in industries, such as the pharmaceutical industry, food industry and chemical industry. Compared with conventional thermal technologies, organic solvent nanofiltration (OSN) avoids any phase transition, which has attracted increasing interests to reduce the energy consumption in chemical processes. A highly permeable and selective membrane is desired for an energy efficient separation process. Commercialized OSN membranes fabricated by covalent crosslinking of polymers have the drawback of having a low solvent permeability. Alternatively, thin film composite (TFC) membranes consisting of a top nanoscale layer and a porous substrate allow to tune the layered structure. The nanometer thin film has a great potential to provide an ultrafast permeance for OSN membranes. However, challenges remain concerning the solvent stability and the precise selectivity of the composite membrane. Exploring robust substrate materials and rational designing the pore structure of the selective layer are the key for the development of high performance OSN membranes. This thesis aims to address the aforementioned problems via introducing a new kind of nanofibrous substrate and architecting the membrane pore sizes/structure on a molecular level through chemical reactions and solvent activation. Different amine monomers, including two kinds of aromatic diamines, m-phenylenediamine (MPD), m-xylylenediamine (m-XDA) and one aliphatic polyamine, polyethyleneimine (PEI), were explored to synthesize the selective layer.