In-situ monitoring of polyelectrolytes adsorption kinetics by electrochemical impedance spectroscopy: Application in fabricating nanofiltration membranes via layer-by-layer deposition

Monitoring early zeolite formation via in situ electrochemical impedance spectroscopy.

Hitherto zeolite formation has not been fully understood. Although electrochemical impedance spectroscopy has proven to be a versatile tool for characterizing ionic solutions, it was never used for monitoring zeolite growth. We show here that EIS can quantitatively monitor zeolite formation, especially during crucial early steps where other methods fall short.

Adsorption Mechanisms in Layer-by-Layer Films

Layer-by-layer deposition of oppositely charged polyelectrolytes on the surface of condensed DNA particles.

DNA can be condensed with an excess of poly-cations in aqueous solutions forming stable particles of submicron size with positive surface charge. This charge surplus can be used to deposit alternating layers of polyanions and polycations on the surface surrounding the core of condensed DNA. Using poly-L-lysine (PLL) and succinylated PLL (SPLL) as polycation and polyanion, respectively, we demon...

Electrochemical Monitoring of TiO2 Atomic Layer Deposition by Chronoamperometry and Scanning Electrochemical Microscopy

The scanning electrochemical microscope (SECM) was used to characterize the atomic layer deposition (ALD) of TiO2 on indium-doped tin oxide (ITO) substrates by studying electron transfer through pores in the thin films (1−5 nm thickness). The extent of electron transfer, and thus the porosity of the films, was evaluated by transient electrochemistry. These studies show that ALD deposition of Ti...

Charge Inversion and Layer-by-Layer Assembly of Flexible Polyelectrolytes

We have applied a continuum self-consistent field (SCF) theory to flexible polyelectrolytes on flat surfaces which are either uncharged or carrying the opposite charge as the polyelectrolytes. We examined in detail the effects of various parameters on the polyelectrolyte adsorption and surface charge compensation by the adsorbed polyelectrolytes. The ground-state dominance approximation (GSDA) ...