Use of intumescent flame-retardant systems in epoxy adhesives for debonding purpose.

This work investigates the use of intumescent flame-retardant additives as a new debonding solution to disassemble bonded aluminum substrates. Melamine polyphosphate (MPP) or ammonium polyphosphate (APP) was incorporated into an epoxy adhesive joint as both an acid source and a swelling agent with this stimulus responsive behavior being triggered by heating. The ability of the system containing intumescent additives to swell and foam under heat radiation was efficiently exploited to provide enough local pressure to induce porosities and cracks at the interface, facilitating the disassembling of bonded aluminum substrates.

Changes in permeability and in mechanical properties of layer-by-layer films made from poly(allylamine) and montmorillonite postmodified upon reaction with dopamine.

Polyelectrolyte multilayer (PEM) films present a versatile surface functionalization method allowing to address many applications. These coatings suffer; however, from weak mechanical properties this problem can be addressed by the regular incorporation of clays in the layering process. To allow for an even better control of a whole set of film properties, among them their thermal stability, their stability in water, and their impermeability to anions, we postmodify (PAH-MMT)(n) films with polydopamine, by putting the pristine PEM films in contact with an oxygenated dopamine solution.

Peculiar reduction of graphene oxide into graphene after diffusion in exponentially growing polyelectrolyte multilayers.

In the present work, in situ reduction of graphene oxide (GO) into graphene was preformed, after diffusion in exponentially growing polyelectrolyte multilayers, using sodium citrate as the reducing agent. First, the graphene oxide was obtained by treating a commercial grade of Expanded Graphite (EG). Based on XRD and Raman spectroscopy results, a complete exfoliation of graphene nanopellets down to one layer was achieved during the oxidation process.

Influence of the nature of the polycation on the adsorption kinetics and on exchange processes in polyelectrolyte multilayer films.

The deposition of polyelectrolyte multilayer films (PEMs) appears more and more as a versatile tool to functionalize a broad range of materials with coatings having controlled thicknesses and properties. To increase the control over the properties of such coatings, a good knowledge of their deposition mechanism is required. Since Cohen Stuart et al.

Diffusion of polyphosphates into (poly(allylamine)-montmorillonite) multilayer films: flame retardant-intumescent films with improved oxygen barrier.

The present paper relies on the original idea to design multifunctional coatings, and in particular highly efficient intumescent flame retardant coatings, based on the diffusion of polyphosphates (PSPs) in exponentially growing "layer-by-layer" films made from montmorillonite (MMT) and poly(allylamine) (PAH). Here, we used polyphosphates as an acid source, polyallylamine as both a carbon source and a swelling agent, and finally clays to reinforce the intumescent char strength and also for their oxygen barrier property. The coatings made from the alternated deposition of n = 60 layer pairs of PAH and MMT reach a considerable thickness of ∼18 μm with well-defined ordering of the MMT in the direction parallel to the substrate.