Polarized and depolarized dynamic light scattering from a block copolymer melt

Dynamics of ternary polymer blends: Disordered, ordered and bicontinuous microemulsion phases

“…However, in a previous report we described extensive DLS measurements on a PDMSÈPEP diblock of similar weight, which serves as a reference. 16 In that sample three modes were consistently resolved. The slowest, which has the largest amplitude, is the so-called "" cluster mode ÏÏ that appears in most block copolymer and homopolymer melts studied by DLS, and is of no particular interest in the current context.…”

“…Dynamic light scattering measurements were taken on two instruments, one at the University of Minnesota and one at the Institute of Macromolecular Chemistry, as previously described. 16,17 Each instrument has fully adjustable scattering angle, h, and temperature control to ^0.1 ¡C from at least 0 to 200 ¡C. HeNE nm) or Ar`lasers or 514.5 nm) were employed.…”

“…Additional modes have also been reported, however, and remain incompletely understood, as has recently been discussed. 16,44 In a symmetric ternary system it is tempting to postulate two orthogonal modes, one corresponding to Ñuctuations in total A versus total B monomer concentration, and the other to copolymer versus total homopolymer concentration. The Ðrst mode reduces to the single mode seen in the case of a binary blend, and the second mode should be invisible if the homopolymers are homogeneously mixed and the copolymer is truly symmetric.…”

Depolarized Scattering from Block Copolymer Grains Using Circularly Polarized Light

“…12 The applicability of this approach for studying block copolymers was established in the 1990s. To date, it has been used not only to study order−disorder transitions and grain growth in uncharged block copolymer systems 3,5,6 but also for mixtures of block copolymers and Li + salts. 1,7 In addition to working out the protocols for conducting the experiments, we developed quantitative models for determining grain structure from the DPLS profiles.…”

Collective polyelectrolyte diffusion as a function of counterion size and dielectric constant

“…For detection, a fiber‐optic system was used with avalanche photodiodes (EG&G) operated in a cross‐correlation mode. The basic light scattering setup is described in detail elsewhere . For low‐temperature measurements the goniometer was fitted with a special sample holder cooled by nitrogen vapor generated by boiling of liquid nitrogen.…”