purification of drinking and industrial water required usage of high molecular weight polymer to cause flocculation process of dispersed suspension of contaminants. polyelectrolytes, including ionic polyacrylamide are especially appropriate for these purposes, because in this case the suspension stability can be controlled by both steric and electrostatic forces. thus the influence of solution ...

The conformation of polymer chains under confinement is investigated in intercalated polymer/layered silicate nanocomposites. Hydrophilic poly(ethylene oxide)/sodium montmorillonite, PEO/Na+-MMT, hybrids were prepared utilizing melt intercalation with compositions where the polymer chains are mostly within the ~1 nm galleries of the inorganic material. The polymer chains are completely amorphou...

In the case of conjugated polymer chains usually considered as rigid or stiff, it is an open question how the individual chains adopt their conformation inside nanoparticles. Here, the conformation of such a rigid conjugated polymer chain is elucidated for the first time. For this purpose, electron paramagnetic resonance spectroscopy as a method allowing for a direct observation is established.

Small-angle neutron scattering (SANS) is a sensitive technique that is able to probe the structure of polymer-grafted nanoparticles and free polymer chains. Here, we combine SANS measurements with self-consistent field theory (SCFT) calculations to study the structure of deuterated poly(methyl methacrylate) (dPMMA) nanocomposites containing PMMA-grafted Fe3O4 nanospheres, with a specific emphas...

The optical transitions of a chiral, three-substituted polythiophene with an amino acid function can be tuned by interactions with synthetic peptides. The addition of a positively charged peptide with a random-coil formation will force the polymer to adopt a nonplanar conformation, and the intensity of the emitted light is increased and blue-shifted. After the addition of a negatively charged p...

The electronic structure of conjugated polymers is of current interest because of the wide range of potential applications for such materials in optoelectronic devices. It is increasingly clear that the electronic properties of conjugated polymers depend sensitively on the physical conformation of the polymer chains and the way the chains pack together in films. This article reviews the evidenc...

Photophysical processes in conjugated polymers are influenced by two competing effects: the extent of excited state delocalization along a chain, and the electronic interaction between chains. Experimentally, it is often difficult to separate the two because both are controlled by chain conformation. Here we demonstrate that it is possible to modify intra-chain delocalization without inducing i...

Using molecular dynamics with a first-principles-based force field sdenoted MSXXd, we show that large electrostrictive strains s,5%d at extremely high frequencies sover ,109 Hzd can be achieved in a polysvinylidene-fluorided nanoactuator if the packing density of the polymer chains is chosen appropriately. We control the packing density by assembling the polymer chains on a silicon k111l surfac...

The linear polymer chains were approximated as series of identical segments on a simple cubic lattice. The excluded volume was included into the model with no attractive interactions which corresponded to the good solvent conditions. The polymer chains were put into a slit formed by a pair of parallel surfaces. These walls were impenetrable for polymer segments and no other interactions between...