RODLIKE BEHAVIOR OF POLYELECTROLYTE BRUSHES

Spherical charged brushes are studied in the form of block copolymer m icelles. These copolymers are diblocks made of one deuterated, highly charged block and of one protonated, hydrophobic block. Neutron scatte ring with contrast matching enables us to probe selectively the struct ure of the arms of the charged corona of the micelles. A near-perfect rodlike behavior (scattered intensity similar to q(-1)) of the arms is observed at all salt concentrations above an onset in wave vector q(0 ) which increases with salt concentration above a threshold. Results a re strikingly different from what is observed for linear polyelectroly tes, since charged brushes appear very weakly sensitive to the additio n of salt. [S0031-9007(48)07484-5].