title: Solvent induced phenomena in a dendronized linear polymer.
abstract: The properties of a dendronized linear polymer (DP) in dilute solutions depending on solvent quality and temperature are described. The polymer has a contour length ofLc= 1,060 nm. The sample of the fourth generation (PG4) was analyzed in the thermodynamically good solvents dioxane, chloroform, and methanol. The wormlike macromolecule has a persistence lengthlp= 7 nm in dioxane and a cross-section radius determined by small angle X-ray scattering (SAXS) ofRc (SAXS)= 2.8 nm. The bulk density of PG4 determined by SAXS was compared with solution density. Evidence for substantial swelling of the cross-section was found. Toluene acts as a thermodynamically poor solvent (θsolvent). Above theθtemperatureTθ, a strong temperature dependence of the size and the Young's modulusEwas observed. Following Odijk,E/kBT∼1 was found. BelowTθ, a regime characterized by unswelling of the wormlike chains was observed. The results suggest that DPs can be described as soft colloid filaments, which are subject to commonly observed interactions in colloidal systems. A phase diagram indicates a regime belowTθin which fluctuations of osmotic pressure inside the filaments result in periodic undulation of the chains. In summary, introducing a dense dendritic shell around the backbone converts conventional polymers into molecular colloids. Figureᅟ
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Kroeger
authors.forename: Baozhong
authors.initials: B
authors.lastname: Zhang
authors.forename: Christine
authors.initials: C
authors.lastname: Rosenauer
authors.forename: A Dieter
authors.initials: AD
authors.lastname: Schlüter
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wegner
keywords: Colloidal filaments; Dendronized polymers; Morphological instability; Phase separation; Solution behavior