The formation of micelles, micellar clusters, and aggregates in aqueous solutions of polystyrene-blockpoly(ethylene oxide) macromolecules (PS-b-PEO) in the presence of various additives is studied. Behavior of the PS-b-PEO micellar solutions is examined with static light scattering and sedimentation in the ultracentrifuge. Sedimentograms of the solution of PS-b-PEO in water exhibit two peaks which correspond to the formation of single micelles (Rg ) 12.8 nm) and secondary micellar clusters (Rg ) 42.1 nm). Experimental data show that the weight fraction of micelles and micellar clusters in the solution strongly depends on the chemical composition of the dispersing media. The addition of 1.5 vol % toluene, which is a good solvent for the glassy polystyrene cores, decomposes the micellar clusters due to an increase of mobility of macromolecules forming micelles. Addition of inorganic salts interacting with poly(ethylene oxide) tails also results in the disappearance of micellar clusters. Alcohols introduced as cosolvents can strongly change the morphology of the amphiphilic PS-b-PEO micelles.

Linear polystyrene of M w = 330 000 and M w/M n = 1.04 in which 50% and 100% of the phenyl residues were chloromethylated were heated in a 0.5 g/L ethylene dichloride solution in the presence of SnCl4 to convert them into an intramolecularly hyper-cross-linked soluble material. The spherical macromolecular species obtained exhibit low density and high surface area (up to 1000 m2/g) and swell strongly in all nonsolvents for linear polystyrene. Solutions in good polystyrene solvents exhibit low viscosity and reduced partial specific volume, but exceedingly high diffusion and sedimentation constants. According to size exclusion chromatography, dynamic light scattering, low angle X-ray scattering and electron microscopy, the diameter of the hyper-cross-linked species is estimated as about 12 nm in the dry state and about 17 nm in solution. In tetrahydrofuran, they associate reversibly, probably forming clusters consisting of 13 regularly packed particles. Because of the partial association, molecular weight measurements (using elastic light scattering and ultracentrifugation techniques) produce values slightly exceeding the 350 000−370 000 expected for the isolated particle.

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Conformational parameters for a wide variety of aromatic cyclochain polymers have been computed assuming free rotation about virtual bonds. The flexibility with free rotation is shown to be determined by the geometry of the repeat unit and can vary over a wide range (15–1500 Å). Experimental values of the Kuhn segment length A are calculated from literature data on the hydrodynamic behavior of polymeric macromolecules of this class in solution. For most polymers Afr for free rotation is equal to the experimental Aexp, and hindered rotation is mainly due to bulky substituents. © 1993 John Wiley & Sons, Inc.

We synthesised P4VP bromides with octyl and dodecyl pendant groups; the bromide anions in these polymer salts were further substituted with dodecylsulfate or bis(2‐ethylhexylsuccinate) anions. Direct SFM visualisation of the original P4VP chains, of the macromolecular salts and of their complexes, showed that the attachment of the pendant groups and especially the complexation with the surfactants promotes stretching of the macromolecules while adsorbing on mica substrate. On the other hand, viscosimetry showed that in solution (chloroform) the comb‐like chains and their complexes with dodecylsulfate had more compact conformations than those of the original P4VP. The scaling exponents describing the correlation between the contour length and the end‐to‐end distance of the adsorbed macromolecules were found to be ca. 3/4, which is indicative of 2D self‐avoiding walk statistics.magnified image