Probe diffusion in polymer solutions under .THETA. and good conditions

摘要: Quasielastic light scattering was used to measure the diffusion coefficient of 67-nm-diameter polystyrene latex spheres through aqueous solutions M w =1.39×10 5 (hydroxypropyl)cellulose at temperatures 41°C (near-θ conditions) and 10°C (good-solvent conditions). At both temperatures, D described well by a stretched exponential form exp(-αc ν ), with ≃ 1 under θ conditions but 3/4 in good solvent. The observed solvent-quality dependence κ is quantitatively predicted several modes probe diffusion, including hydrodynamic scaling de Gennes-Langevin-Rondelez transient gel model