Défauts dans des phases lamellaires lyotropes observés par cryofracture et microscopie électronique

Samples of aqueous solutions of C 12 EO 5 and C 12 EO 6 have been quenched from various temperatures, cryofractured and then observed by electron microscopy. Analysis of micrographs shows that: i) the concentration of screw dislocations increases with temperature; ii) screws of the same sign build walls; iii) screws of opposite signs gather in pairs linked by a step to build dislocation loops which cross the layers. These defects are compared to highly curved defects revealed by E.P.R. in the same systems [1] L'analyse des micrographiesmontre que la concentration des dislocations vis croit avec la temperature, les vis de meme signe forment des parois et les vis s'assemblent deux par deux de signes opposes pour former des boucles de dislocations traversant les lamelles