Polymethylmethacrylate probe diffusion

Nemoto, et al. report sedimentation and tracer diffusion of dilute polymethylmethacrylate probes in dilute and nondilute polystyrene thiophenol(24,25). Polystyrene and thiophenol are isopycnic, permitting s of PMMA probes in polystyrene thiophenol to be determined unambiguously with ultracentrifugation. 

Figure 9.28 Probe diffusion coefficients for (a) 350 kDa polymethylmethacrylate in good solvents tetrahydrofuran (O) and N,N-dimethylformamide (0), and the Theta solvent dioxane water ( ), after Gold, et al.(45), and (b) 67 nm polystyrene spheres in aqueous 139 kDa HPC at (O) 10 °C (good solvent conditions) and ( ) 41 (pseudo-theta point), after Phillies and Clomenil(46).

As seen in Figure 12.27a, the effect of solvent quality on viscosity was obtained by Gold, et al, as part of a study of probe diffusion(57). The polymer was 350 kDa polymethylmethacrylate. Good solvents were dimethylformamide (DMF)... 

Fluorescence depolarisation studies on mixtures of isotactic and syndiotactic polymethylmethacrylate have shown the formation of a 1 2 complex in toluene while fluorescence anisotropy studies on polybutadienes have shown viscous rotational diffusion with slipping boundary conditions OS. Fluorescence studies on quasi-rigid-rod like probes in anisotropic polyethylene have shown... 

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