A Modified Random Phase Approximation of Polyelectrolyte Solutions

We compute the phase diagram of salt-free polyelectrolyte solutions using a modified Debye-Huckel Approach. We introduce the chain connectivity via the Random Phase Approximation with two important modifications. We modify the electrostatic potential at short distances to include a bound on the electrostatic attractions at the distance of closest approach between charges. This modification is shown to act as a hard core in the phase diagram of electrolyte solutions. We also introduce a cut-off on the integration of the modes of wave length smaller than the size over which the chains are strongly perturbed by the electrostatic interactions. This cut-off is shown to be essential to predict physical phase diagram in long chain solutions

Mesoporous nickel/nickel oxide-a nanoarchitectured electrode

Metallic nickel was electrodeposited from aqueous nickel(II) acetate dissolved in the lyotropic liquid crystalline phases of Brij 56 and Brij 78 surfactant templates to form metal films with hexagonal arrays of nanometer-sized channels. The applicability of these materials as inexpensive, large area and low-resistance current collectors was demonstrated by cyclic voltammetry. The redox charge capacity of the surface oxide in aqueous KOH was enhanced by 2 orders of magnitude over that of a nontemplated sample with no detectable impedance of the reaction rate