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The Brownian dynamics method is employed to study the formation of an electrical double layer (EDL) on the metal nanoparticle (NP) surface in hydrosols during adsorption of electrolyte ions from the interparticle medium. Also studied is the charge accumulation by NPs in the Stern layer. To simulate the process of the formation of EDL, we took into account the effect of image forces and specific adsorption, dissipative and random forces, and the degree of hydration of adsorbed ions on the EDL structure. The employed model makes it possible to determine the charge of NPs and the structure of EDL. For the first time, the charge of both the diffuse part of EDL and the dense Stern layer has been determined. A decrease in the electrolyte concentration (below c

The model of pairwise elastic repulsion of contacting colloidal nanoparticles with a rigid core and deformable shell is discussed. A simple analytical equation is applied for the energy of elastic repulsion of nanoparticles with arbitrary sizes and the elasticity moduli of self-healing polymer adsorption layers. The model is based on the representation of the absorption layer as a continuous medium that is elastically deformed upon the contact of nanoparticles. The major characteristic of this medium is the elasticity modulus. The magnitude of the elasticity modulus is determined from the condition of balance of the van der Waals attractive forces of nanoparticles and the elastic repulsion of their adsorption layers in the contact area, taking into account the temperature variations. We employed the kinetic approach to describe the dependence of the elasticity modulus on both the temperature and the rate of its change.

We have shown significant suppression of resonant properties of metallic nanoparticles at the surface plasmon frequency during the phase transition “solid–liquid” in the basic materials of nanoplasmonics (Ag, Au). Using experimental values of the optical constants of liquid and solid metals, we have calculated nanoparticle plasmonic absorption spectra. The effect was demonstrated for single particles, dimers and trimers, as well as for the large multiparticle colloidal aggregates. Experimental verification was performed for single Au nanoparticles heated to the melting temperature and above up to full suppression of the surface plasmon resonance. It is emphasized that this effect may underlie the nonlinear optical response of composite materials containing plasmonic nanoparticles and their aggregates.