title: Bundle formation in polyelectrolyte brushes.
abstract: Bundle formation of the vertically oriented polyelectrolytes within polyelectrolyte brushes is studied with x-ray reflectivity and grazing-incidence diffraction as a function of grafting density and ion concentration. At 0.8 Molar monomer concentration and without added salt, a bundle consists of two chains and is 50 A long. On the addition of up to 1M CsCl, the aggregation number increases up to 15 whereas the bundle length approaches a limiting value, 20 A. We suggest that the bundle formation is determined by a balance between long-ranged electrostatic repulsion, whose range and amplitude is decreased on salt addition, and short-ranged attraction.
authors.affiliation: Institut für Physik, Universität Greifswald, Felix-Hausdorff-Str. 6, D-17487 Greifswald, Germany.
authors.forename: J U
authors.initials: JU
authors.lastname: Günther
authors.forename: H
authors.initials: H
authors.lastname: Ahrens
authors.forename: S
authors.initials: S
authors.lastname: Förster
authors.forename: C A
authors.initials: CA
authors.lastname: Helm
mesh_terms: D002586:Cesium / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D002712:Chlorides; D004573:Electrolytes; D011108:Polymers; D002586:Cesium; C028019:cesium chloride