International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Compositions of mechanoactivated silicatecontaining particles used as modifiers of polymer matrices have been developed. The morphology, particle sizes of the modifier, the nature of their distribution in the polymer matrix, as well as the topography of the friction surface of samples from modified polymers were studied using scanning electron and optical microscopy. Introduction of mechanically activated particles in concentrations from 0.01 to 2 wt. % into the polymer matrix of a reactoplastic polymer based on epoxy resin leads to multilevel modification, expressed in a change in the morphology of the test sample at the supramolecular, intermolecular and molecular levels. The effect of additives of nanophase modifiers on the wear rate of the developed nanocomposite materials is investigated. The introduction of composite mechanically activated nanodispersed particles into a reactive polymer based on epoxy resin leads to a decrease in the coefficient of friction in the studied range of modifier concentrations, loads and test speeds. Studies of the morphology of the surface of the analyzed samples have shown the presence of a separation layer on the surface of rubbing bodies, contributing to a significant decrease in the coefficient of friction. In the structure of this coating, the presence of nanophases is observed, which have a positive effect on the wear resistance of the developed composite material.

Laser ablation in liquid is an eco-friendly and efficient method to produce nanomaterials with interesting properties in a laboratory scale. Previously reported ZnO nanoparticles, obtained by nanosecond and millisecond pulsed laser under various laser parameters, demonstrated photocatalytic, gas-sensing, and antibacterial activity. Here we explore the possibility for laser ablation of Zn metal plate in natural zeolite suspension and isolation of a composite ZnO-Zeo. It was characterized by UV-vis, XPS and SEM methods. The characteristic UV-vis peak for ZnO nanoparticles was observed at 340 nm, which is associated with small particles size, proven by SEM images to be 30-50 nm. The spherical ZnO particles are located on the zeolite surface. It was found that the attraction forces between both phases cause a shift in Zn 2p XPS peak positions which were determined at 1022.0 eV and 1045.1 eV for 2p3/2 and 2p1/2 levels, respectively. The approach for laser ablation in suspension could open avenue for simultaneous formation and incorporation of various nanoparticles into different supports.

ZnO nanosized materials are well known for their photocatalytic and antibacterial properties. Their implication in water treatment and environmental protection, especially as a part of composite materials, has been an object of study of a great number of researchers working in the field. Zeolites are excellent candidates for support of composites preparation with semiconductor oxides since they are nonhazardous, non-expensive and naturally abundant materials. In order to synthesize nanosized ZnO with well-developed surface area and uniform size distribution in pristine form and supported on zeolite, we applied the method of precipitation assisted by sonicatio n. As prepared ZnO nanoparticles and the composite ZnO-zeolite were characterized by XRD, SEM and UV-Vis spectroscopy. The ZnO crystalized in wurtzite structure in both materials. The morphology of ZnO nanoparticles was affected by the zeolite framework, as in the composite the ZnO was formed in-situ at the presence of zeolite. The ultrasonic irradiation during the precipitation of Zn(OH)2 and aging of the reaction mixture causes activation of the zeolite surface and prevents the aggregation of ZnO particles. In result evenly distributed ZnO nanoparticles were obtained in the composite.

The methodological principles for the implementation of the concept of multilevel modification of polymer matrices by components with given energy parameters to obtain nanocomposites with a synergistic com-bination of performance characteristics have been developed.
These principles based on:
– established crystal-chemical prerequisites for the natural and synthetic carbon-, metal- and silicon-containing semi-finished products choice for the directed formation of active nanosized particles with given structural, morphological and energy parameters under optimal technological impact (mechanical and chemical, thermal, laser);
– implementation of the conditions for the energetic compliance of nanomodifiers to the prevailing mechanism for the formation of the optimal structure of polymer, oligomer and blend matrices at various levels of organization – molecular, supramolecular and interphase;
– creating the conditions for the reveal of the prevailing mechanisms of interphase physical and chemical interactions of components with the formation of boundary layers of the optimal structure, which deter-mine the mechanisms of destruction of products from nanocomposites under various operational factors impact;
– achieving the conditions for the synergistic effect of structuring by using a complex of modifiers with a certain combination of parameters of dimensional, geometric and energy characteristics.

The analysis of the mechanisms of implementation of the concept of multilevel modification in materials science and technolog y of polymer nanocomposites is carried out. It has been shown that the mechanisms of structure formation at the molecular, supramolecular and interfacial levels in nanocomposite materials based on industrial polymers of the class of polyamides, polyolefins, fluoropla stics modified by components that implement the nanostate phenomenon are based on:
– the formation of adsorption physical bonds in the boundary surface due to the energy interaction of active centers of nanosized particles with various shapes and components of the surface layer, which change the parameters of the rheological, stress-strain and adhesive characteristics of the composites;
– the demonstration of a structuring action by nanosized particles and components of the surface layer of particles, which mani fests itself in the form of supramolecular and interphase ordering, physical compatibilization and non-chain stabilization, which increase the thermodynamic compatibility of the components of polymer-polymer and polymer-oligomer blends and inhibit thermo-oxidative and destructive processes in composites, causing a non-additive increase of the parameters of their stress-strain, adhesive and tribological characteristics.

Magnetic matrices for SMC powders by nanocomposite magnetic materials electroplating on copper foil rings with 50 μm thick were obtained. For each type of magnetic SMC matrices were measured magnetic properties in a transformer mode on a sinusoidal signal. As a result of the conducted research, it was shown that the application of the technique of applying composite nanomodified materials to a special substrate will allow the formation of heterogeneous composite magnetic components with the use of SMC material for microelectronics.

In this article, graphene nanoplatelets (GN) were used as nanofiller and twin-screw extrusion process was applied to synthesis of Polyamide 6 / Graphene Nanoplatelets (PA6/GN) nanocomposites. Fourier-Transform Infrared spectroscopy (FTIR), X-Ray Diffractions (XRD), and Thermogravimetric analysis (TGA) were used to characterize the resultant structure. According to the results of FTIR and XRD measurement, α phase dominated in neat PA6, while the γ phase also could be observed at PA6/GN nanocomposites. Compared with the neat PA6, the PA6/GN nanocomposites exhibited better improvement in thermal analysis results due to the new and dominant crystal form.