Static and Dynamical Properties of Polystyrene in trans-Decalin. 1. NBS 705 Standard Near θ Conditions

Effects of polydispersity, branching and chain stiffness on quasielastic light scattering

“…At sufficiently small valuesThf , the same relation holds strictly for arbitrary solutes only if there is no coupling between translational and rotational or deformational motions. If, as is usually true (see below), the effects of this coupling cannot be seen experimentally, then observations of S(q,t) for polydisperse solutions offer information about the distribution of D. Chu and coworkers (5,6) and Provencher and coworkers (7,8) have implemented practical methods for inverting such data, closely related to similar tasks long confronting students of the ultracentrifuge.…”

Dynamical Properties of Polymer Solutions from Θ to Critical Regions as Measured by Quasi–Elastic Light Scattering: Polystyrene–Methylcyclohexane System

“…The fraction of the fast-mode decreases with decreasing moPolymer J., Vol. 16 18 The present analysis shows that the bimodal distribution exists even at the critical concentration and near the critical temperature in higher molecular weight samples. The F of the total correlation function and the average line width for the slow mode had a similar temperature dependence, and no appreciable temperature dependence was found in the fraction of each mode.…”

“…log D -log t plot decreases with decreasing t and approaches v defined by Therefore, the mean value of v' for the entire t-range is larger than v, consistent with the result of Candau et al/ 6 this suggests that D does not obey the relation D -1 in any part of the range oft. Figure 4 shows a double logarithmic plot of the diffusion coefficient at a fixed t-value (t= 0.007), D 0 ', against molecular weight, indicating a molecular weight dependence of the critical amplitude of D. A least-squares fitting to this plot gave (18) We also obtained by a least-squares fitting, where 6nYf* D 0 ' and Tis the temperature at t = 0.007 Polymer J., Vol. 16, No.…”

“…At concentrations comparable to or higher than C*, the correlation function near the 8-temperature shows a bimodal decay even in the region of kR 8 < 1. 18 Thus, the profile of the correlation function should be taken in a consideration of the dynamical behavior near the critical point in polymer solutions.…”

Hydrodynamic radius of polystyrene around the θ temperature. 2

“…only two exploratory studies seeking to establish that such phenomena may exist had been p~b l i s h e d .~.~ On the other hand, association between lignin components can be further complicated by aggregation between the resulting complexes. [6][7][8] Marked associative interactions among lignin components are conveniently documented by the striking variations between gel permeation chromatographic profiles observed with different eluants. The effective distributions found when nonaqueous solvents (or nonaqueous solvent-water mixtures in the absence of added salts) are employed exhibit a well-defined multimodal pattern of species extending to very high molecular weights, while those obtained with alkaline aqueous eluants generally consist of a broad envelope of components with distinguishable features apparent only in the lower molecular…”