Radius of Gyration of Polystyrene Combs and Centipedes in a O Solvent

• Published in: Macromolecules Vol. 38; no. 4
• Main Authors: Terao, Ken, Farmer, Brandon S, Nakamura, Yo, Iatrou, Hermis, Hong, Kunlun, Mays, Jimmy
• Format: Journal Article
• Language: English
• Published: United States 01.01.2005
• Subjects: DECALIN; GEL PERMEATION CHROMATOGRAPHY; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LIGHT SCATTERING; MOLECULAR WEIGHT; MOTION; POLYSTYRENE; REFRACTIVE INDEX; SOLVENTS; TETRAHYDROFURAN
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma049485s

The molecular weight dependence of the radii of gyration R{sub g} in a {var_theta} solvent (trans-decalin) of one regular branched comb and three regular centipede polystyrenes was studied using a gel permeation chromatography system equipped with a two-angle light scattering detector and a refractive index detector. R{sub g} in trans-decalin for each sample of particular molecular weight was about 25% smaller than that in a good solvent (tetrahydrofuran, THF). On the other hand, they are 20--40% larger than the theoretical values from the Gaussian chain model. This difference can be explained with the wormlike comb model developed by Nakamura et al. (Macromolecules 2000, 33, 8323-8328). Persistence lengths thus obtained for each sample were about half of that determined in THF solution. However, they are significantly larger than that for linear polystyrene. These results suggest that a main chain stiffening effect exists in comb polystyrenes even in a {var_theta} solvent.