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Despite their unprecedented potential, polymer nanocomposites (PNCs) have not reached their forecasted industrial utilization, yet. Insufficient control of nanoparticle (NP) spatial organization in the polymer matrix was recognized as the bottleneck of further PNC applications. Therefore, thermodynamic parameters enabling a general estimate of the nanocomposite (NC) structure in any polymer solution were investigated in this study. The effect of polymer–particle–solvent interactions on the final NP dispersion in PNCs was examined in depth. Our approach was based on assessing the surface charge (ζ-potential) of NPs and specifying the difference in solubility parameters between the polymer, nanoparticles, and the solvent used during the preparation. To generalize our findings, four different polymer matrixes, poly­(methyl methacrylate) (PMMA), poly­(vinyl acetate) (PVAc), polycarbonate (PC), and polystyrene (PS), and three types of NPs, spherical colloidal and fumed nanosilica and functional ZnO2 doped with Al2O3 NPs blended in various solvents, were investigated. The overall interaction balance present in the PNC solution was estimated using solubility parameters and ζ-potential (represented by polarity index), and the influence on final NP dispersion after NC solidification was described. This approach offers a valuable tool that only requires several readily accessible physicochemical parameters (solubility parameters and ζ-potential) as an input for the structural prediction of the final PNCs. Hydrogen bonds play an important role in the formation of the PNC structure due to the absorption of polymer chains onto the NP surface. Generalized features described on a wide range of composition and preparation conditions will help to advance the fundamental understanding of NP self-assembly in polymer liquids. Moreover, the presented relation between the solvent–polymer–particle interaction strength, NP spatial organization, chain stiffness, and relaxation properties, which was evaluated by comparing PNCs with various matrixes, will contribute new evidence to the general description of the PNC’s structure-property function. As an addition, we present anisotropic microstructures composed by the self-assembly process of spherical NPs prepared in dioxane.

The present study is focused on the synthesis and investigation of the physicochemical and biological properties of silver nanoparticles stabilized with a series of cationic gemini surfactants having a polymethylene spacer of variable length. UV-VIS spectroscopy, dynamic light scattering, scanning electron microscopy and zeta potential measurements were applied to provide physicochemical characterization of the silver nanoparticles. The mean size values of the nanoparticles were found to be in the 50 to 115 nm range. From the nanoparticle size distributions and scanning electron microscopy images it results that a population of small nanoparticles with the size of several nanometers was confirmed if the nanoparticles were stabilized with gemini molecules with either a short methylene spacer (two or four −CH2− groups) or a long spacer (12 −CH2− groups). The average zeta potential value for silver nanoparticles stabilized with gemini molecules is roughly independent of gemini surfactant spacer length and is approx. +58 mV. An interaction model between silver nanoparticles and gemini molecules which reflects the gained experimental data, is suggested. Microbicidal activity determinations revealed that the silver nanoparticles stabilized with gemini surfactants are more efficient against Gram-negative bacteria and yeasts, which has a direct relation to the interaction mechanism of nanoparticles with the bacterial cell membrane and its structural composition.

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