4(%3)3 - Ecole nationale supérieure de chimie de Montpellier

gain onto the electrodes by building multilayers or reorganization of micelles into a more compact order.On the other hand, almost no F increase is observed with PSAN(7.5k)-b-PEO(35k)-b-PSAN(7.5k)signifying a reduced proportion of block copolymer bridges.2.5 FLUID FLOW EXPERIMENTS OF THE MEMBRANEThe term “fluid flow experiments” represent the water permeability experiments conducted forthe membrane in a simple dead-end filtration cell at different pressure regimes. The amount of waterpermeated through the membrane at a given pressure was collected in a recipient. The increase in therecipient’s weight was monitored using a balance while simultaneously recorded by the computersoftware. In this fashion, the evolution in the amount of water with respect to time could be plotted atgiven water pressure.Figure – 2.9: Water flux response of a classical membrane with respect to a dynamic membraneUnlike classical membranes which are first conditioned at high pressure before being subjectedto permeability tests, a dynamic membrane like ours cannot be conditioned. This is due to ever changingflux values over the course of time exhibited by the membrane at each pressure value. Therefore, whilethe flux curve for a classical membrane is marked by a constant straight line in function of time, in caseof a dynamic membrane it follows a polynomial trajectory (Figure – 2.9). In the present case, flux curveswere obtained for the membrane at different pressure values (Figure – 2.10). As it can seen, the fluxvalues rapidly decrease with time and approach near zero value for longer duration of time.54