Novel Layer-by-layer Complexation Technique and Properties of the Fabricated Films

Abstract

A novel layer-by-layer complex-fabrication technique for multilayer film assembly was developed by alternatively dipping desired substrates in macromolecular ligands and Eu 3+ ion solutions. A water-soluble, luminescent thiophene-based polymer, viz., poly [2,5-(3carboxymethyl urethanyl ethyl) thiophene] (H-PURET), was prepared and used as the macromolecular ligand. Multilayer deposition was monitored using UV-visible spectroscopy by following the absorbance increase due to the deposition of the polymer layer. Multilayer thin films were characterized using infrared and fluorescence spectroscopic techniques, transmission electron microscopy (TEM), and energy-dispersive X-ray spectrometry (EDXS). The conductivity and the electroluminescence properties of the conjugated polymer-Eu 3+ complex multilayer films were also measured. The observed electroluminescence intensity of conjugated polymer-metal complex multilayer film was about 2 times higher than for the conjugated polymer by itself. The approach is general in that other macroligands and metal ions may be employed.

Assembly of Alternated Multivalent Ion/Polyelectrolyte Layers on Colloidal Particles. Stability of the Multilayers and Encapsulation of Macromolecules into Polyelectrolyte Capsules

“…The question arises of what might be the limit of number charges the molecules should have to ensure layer-by-layer adsorption. In (12)(13)(14) it was shown that the multivalent dyes or ions can be used for multilayer build-up on macroscopic flat surfaces, but these films are not stable in high ionic strengths. In relation to polyelectrolyte capsules the possibility to vary the stability of the capsule wall composed of multilayers opens perspectives to control capsule degradation and release of encapsulated materials.…”

Layer‐by‐layer films based on charge transfer interaction of ϕ‐conjugated poly(dithiafulvene) and incorporation of gold nanoparticles into the films

“…3 Forces between the layers are primarily electrostatic interaction and covalent bonding, but they can also involve hydrogen bonding, p-p interaction, and coordination bonding of monomeric or polymeric ligands with transition metal ions. 4,5 A relatively weaker charge transfer (CT) interaction as the driving force of the LBL self-assembly was recently used to prepare ultrathin films. [6][7][8][9] Incorporation of noble metal nanoparticles into the LBL films consisting of pconjugated conducting polymers presents promising materials for both catalytic applications, in which conducting polymer beds with catalyst nanoparticles gathering close to the film surfaces provide optimum catalytic situations, and nanotechnological fabrication.…”

Interfacially formed organized planar inorganic, polymeric and composite nanostructures

“…Layer-by-layer assembled films were used as nanoreactors for generation of inorganic nanoparticles [110]. Surface complexation and sequential ligand exchange reactions in transition metal cation complexes also allowed for the growth of thin polymeric films through layer-by-layer stepwise adsorption procedure [111,112]. That approach was used to produce slowly soluble films formed by PSS/Tb 3+ complex in polyelectrolyte nanocapsules [113].…”