Introduction to Polyelectrolyte Chain

By combining small-angle X-ray scattering, wide-angle X-ray scattering, and rheology, the effect of additional polyelectrolyte chains on interactions among spherical polyelectrolyte brushes (SPB) was systematically investigated both on microscopic and macroscopic levels.

Our findings provide a detailed molecular picture of ion condensation and reveal the severe effect of a few, selective and localized electrostatic interactions on the rigidity of a polyelectrolyte chain.

By means of the density functional theory framework (DFT) as well as the molecular dynamic simulations (MD), a polyelectrolyte chain (PE) in the good solvent conditions at thermal equilibrium is studied.

In the present work we analyze in details this effect in the case of slowly moving Pearl-Necklace-like Polyelectrolyte Chain of structural charge ZSe, and length L less than the structural length LS = ∣ZS∣bS, constituted by Nb beads separated alternatively by (Nb- 1) strings enclosing Ng groups (or small thermal blobs).

The presence of electrostatic and steric interparticle forces induced by the adsorbed polyelectrolyte chains was assumed.

Interestingly, further studies demonstrated that the enhancement of water transport was not only dependent on the hydrophilicity of the polyelectrolyte chains, but also influenced by their flexibility in the solvent.

It was found that the chlorination process increases the negative charge density of the membrane surface and enlarges the free volumes between the polyelectrolyte chains.

The effect of binding strength of counterions with the polyelectrolyte chain to the swelling of polyelectrolyte brushes is studied, by investigating the swelling of both the polycation and polyanion in response to the variation of the salt concentration under the change of counterion's identity.

The dynamics of adsorption and desorption of counterions on a polyelectrolyte chain in aqueous solution is studied at a single molecular level.

Polyelectrolyte-surfactant interaction used to be studied in dependence on nature of head-group of cationic surfactant and polyelectrolyte chain and their influence on colloidal-chemical parameters of polyelectrolyte-surfactant complexes has been compared.

The resulting disjoining pressure shows a crossover to a repulsive regime when the interplate separation gets smaller than the size of the polyelectrolyte chain, followed by an attractive part.

As a quantitative measure of the distribution of counterions around the polyelectrolyte chain, we study the radial distribution function between monomers on different polyelectrolytes and the counterions inside the counterion worm surrounding a polymer chain at different concentrations of the divalent salt.

In this study, we have performed coarse-grained molecular dynamics simulations to understand the charge-driven self-assembly of spherical nanoparticles grafted with polyelectrolyte chains.

The polyelectrolyte chains form a network with nanopores on the ceramic surface and promote the rejection of small molecules such as pharmaceuticals, salts and industrial contaminants, which can otherwise not be eliminated using standard ultrafiltration methods.

However, while Nafion membrane evolves from a micellar solution through the formation of a phase-separated gel, forming an oriented supported membrane, sPSS membrane evolves from a solution of dispersed polyelectrolyte chains via formation of an inhomogeneous gel, showing assembly and ionic phase separation only at the end of the drying process.

We find that the polyelectrolyte chain cross-section remains largely unperturbed by gelation and identify three hierarchical structural features at larger length scales.

To pinpoint the mechanism of surface structure formation, the shape factor of two species of polyelectrolyte chains and the pair correlation function between monomers from different polyelectrolyte ligands are analyzed carefully.

DNA in its double helical structure is a semi-rigid polyelectrolyte chain.

Bridging events caused by Dy3+ or Y3+ between polyelectrolyte chains largely affected current blockage and dwell time of the translocation events.

Polystyrene microparticles were covalently impregnated into the networks of functional polyelectrolyte chains designed via a tandem run of three reactions: (i) synthesis of water-soluble polyelectrolyte, (ii) fast azidation and (iii) a ‘click’ reaction, using the single-catalyst, single-pot strategy at room temperature in mild aqueous media.

Polyelectrolyte chains adsorb on the surfaces in a thin charged layer, acting as a nonattractive wall for the bulk solution.

These substantial improvements in adsorption performance are driven by the mediating effect of the anionic dyes (acting as the electrostatic mediator between the positively charged polyelectrolyte chains and organoclays), enabling the formation of true hybrid sorbent structures without the need for covalent cross-linking chemistry.

FS appears to be chemically stabilized by the interaction with polyelectrolyte chains.

Using molecular dynamics simulations, the flexible ring polyelectrolyte chains tethered to a planar substrate and immersed in good solvents are investigated systematically.

In particular, the roles that the applied pH, electric potential gradients, and the grafting density of the polyelectrolyte chains played are examined in detail.

In an effort to rationalize our experimental findings we present a theory for the collective dynamics of polyelectrolyte solutions with salt by addressing the coupling between the relaxations of polyelectrolyte chains, counterions from the polymer and added salt, and co-ions from the salt.

The swelling dynamics for protein layer were fitted with an existing polyelectrolyte chain swelling model.

Ultraviolet-B irradiation of the HMC suspensions induces an efficient crosslinking between adjacent polyelectrolyte chains through the formation of thymine photodimers, such as the cyclobutane pyrimidine dimer (CPD) and the (6-4) pyrimidine-pyrimidone photoproduct (6-4PP).

The quantitative analysis demonstrates that counterion release is the major driving force for adsorption in a process where proteins become multivalent counterions of the polyelectrolyte chains upon adsorption.

Our simulation results show that the semiflexible polyelectrolyte chain can be regarded as either a flexible polyelectrolyte at small kθ or large N where its radius of gyration RG is larger than the persistence length Lₚ or a stiff polyelectrolyte at large kθ or short N where RG < Lₚ.

The polyelectrolyte chains desorb from the bilayers at a very high salt concentration, in a process similar to the well-known destabilization of complexes of oppositely charged polyelectrolytes.

During single-stage ion activation, the PLL peptide chain mainly underwent backbone cleavages without disruption of the non-covalent interaction which could only be broken via sequential application of electron transfer dissociation (ETD) and collisionally activated dissociation (CAD), indicating strong binding interactions between the two polyelectrolyte chains.

Spherical Polyelectrolyte Brushes (SPBs) are nanoparticles formed by densely-grafted polyelectrolyte chains on the surface of colloidal particles.

Ionic circuits composed of nanopores functionalized with polyelectrolyte chains can operate in aqueous solutions, thus allowing the control of electrical signals and information processing in physiological environments.

The swelling response of the gels in solutions of ten different monovalent salts is found to be practically identical indicating that the principal effect of monovalent ions is screening the electrostatic repulsion among the charged groups on the polyelectrolyte chains; i.