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

2. SELF-HEALING DYNAMIC INTERACTIVE MEMBRANEDynamic Interactive Systems have received considerable interest from scientific communitybecause of their promising novel properties not present at molecular level 1,2 . Understanding andcontrolling such up-scale propagation from molecular level toward nanoscale dimensions 3,4 , mightprovide new insights into the basic features that control the design of emergent systems operating at thecore of advance technologies: tissue engineering 5 , artificial organs 6 , catalysis 7 , membrane filtration 8,9 orsensing 10 . De novo design of porous systems as mechanical supports, molecular capacitors/distributorsor gating effectors by using self-healing 11,12 , self-cleaning 13,14 or stimuli responsive strategies 15 , hasbecome an area of expanding interest. Classical membranes for water filtration are strongly subjected tocompression depending on their structural behaviours and bulk porosity 16,17 . An irreversible compactionis usually undertaken in order to reach a steady state flux, giving the membrane a stable pore size. Onthe contrary, a responsive membrane can undergo a self-regulation of its performance according to thechange in environmental conditions such as pH, temperature, light and ionic strength 18,19 . In this chapter,we shall discuss a novel dynamic interactive membrane based on copolymer micelles which responds topressure and shows variable porosities accordingly and more importantly displays a self-mending ability.2.1 THE COPOLYMERThe building blocks of the membrane are based on an ABA type triblock copolymer (PSAN-PEO-PSAN) consisting of Poly(ethylene oxide) as block “B” in between two “A” blocks of Poly(Styrene – co –Acrylonitrile) block copolymer (Figure – 2.1).Figure – 2.1: Chemical structure of PSAN-b-PEO-b-PSAN copolymer used in this work47