Abstract
The aim of this work is the study of ion and water transport either across bilayer membranes or polymeric membranes used for reverse osmosis. In the first part, this transport through self-assembled synthetic systems was studied; the transport selectivity is in strong relation with the supramolecular structure, formed by weak intra and intermolecular bonds. Ion transport is studied by fluorescence spectroscopy and water transport is studied by light scattering using “stopped flow” technique. The objective is to obtain systems that could imitate transport functions of biomolecules as transmembrane proteins. This functional mimicry is achieved through self-assembly of organic molecules containing imidazole cycle and urea function that can self-assembly and form selective pathways for ion transport. To create the equivalent of the cell membrane, we used unilamellar lipid vesicles. Then, we determined a structure - transport activity relationship for a series of synthesized compounds. For the second part of this work we described the fabrication and the characterization of new thin film composite membranes for water desalination that can present a good balance between permeability and salt rejection. A series of hydrazides as molecular precursors was synthesized in order to replace the metaphenylene diamine (MPD), classically used. Again, hydrogen bonds play an important role, because the rejection is due to a high cross-linking. The polymers synthesized by interfacial polymerization were characterized by infrared spectroscopy, thermogravimetric analysis, and X-Ray diffraction. The membrane films were characterized by scanning electron microscopy, atomic force microscopy and contact angle measurements. Membrane performances were then tested in cross-flow filtration of water and saline solutions.