Constant Magnetic Field as a Tool for Modification of the Properties of Polymer Composites with Silicone Rubber Matrix.

The aim of this research was to obtain new polymer composites with a silicone rubber matrix, having favorable mechanical and functional properties. They contained admixtures in the amount of 10% by weight of expanded graphite (EG) or birch bark (BB). Additionally, some composites contained magnetic particles in the form of carbonyl iron in the amount of 20% by weight. The tensile strength, water absorption, frost resistance, surface contact angle, and free surface energy were examined. Microscopic images were taken using the SEM method and the content of some elements in selected microareas was determined using the EDXS method. In the study, a constant magnetic field with magnetic induction B was used, by means of which the properties and structure of polymer composites were modified. Scientific research in the field of polymers is the driving force behind the progress of civilization. Smart materials are able to respond to external stimuli, such as magnetic fields, with significant changes in their properties. The magnetic field affects not only chemical reactions, but also the crystallographic structure and physicochemical properties of the final products. Owing to their unique properties, such materials can be used in the space industry, automotive industry, or electrical engineering.

Tests of Physicochemical and Mechanical Strength Properties of Polymer Composites on an Epoxy Resin Matrix, Modified by a Constant Magnetic Field.

The aim of the research presented in the paper was to obtain new polymer composites with strong functional properties on the Epidian 5 epoxy resin matrix. The polymer composites contained admixtures of expanded graphite, powder graphite, birch bark containing botulin, and yellow dextrin in set amounts of 20% by weight. Their various mechanical parameters and physicochemical properties were investigated. The research involved determining the effect of a constant magnetic field with magnetic induction B, under the influence of which the parameters and properties of polymer composites have been changed. For example, in a constant magnetic field with an induction of B = 0.5 T there was an increase in the hardness of the composite with an admixture of birch bark from 24.01 to 26.96 N/mm2 (12.3%), or in the composite with the addition of yellow dextrin from 26.12 to 29.93 N/mm2 (14.6%). It was also found, for example, that the water absorption of the resin itself decreased from 0.18% to 0.13%, and the composite with graphite powder from 0.48% to 0.46%. Changes in these parameters, often beneficial, may be important in terms of potential application of those new materials in industry as alternatives.

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment.

In this paper, polymer composites based on polylactide (PLA) and epoxy resin (Epidian 5) were studied in terms of the influence of magnetic induction on their changes in physicochemical properties. The composites contained admixtures in the form of magnetite (Fe3O4) and crystalline cellulose (Avicel PH-1010) in the amount of 10%, 20%, and 30% by weight and starch in the amount of 10%. The admixtures of cellulose and starch were intended to result in the composites becoming biodegradable biopolymers to some extent. Changes in physical and chemical properties due to the impact of a constant magnetic field with a magnetic induction value B = 0.5 T were observed. The changes were observed during tests of tensile strength, bending, impact strength, water absorbency, frost resistance, chemical resistance to acids and bases, as well as through SEM microscopy and with studies of the composition of the composites that use the EDS method and of their structure with the XRD method. Based on the obtained results, it was found that the magnetic induction value changes the properties of composites. This therefore acts as one method of receiving new alternative materials, the degradation of which in the environment would take far less time.

Effects of a Constant Magnetic Field on the Electrochemical Reactions of Quercetin.

The paper presents a study of the effect of a constant magnetic field (CMF) on the basic processes of quercetin electrochemical reactions. According to the observation made in previous studies, the presence of a double bond in the C-ring of quercetin enhances the antioxidant properties of that compound, whereas the presence of -OH groups also affects the antioxidant properties. Using cyclic voltammetry it was found that the constant magnetic field improves the efficiency of quercetin electrooxidation, especially of the third stage of the process, i. e. the stage in which the oxidation of the OH groups in the A-ring is the most difficult. The use of HPLC confirmed the electrochemical measurements and the results of cyclic voltammetry studies. The beneficial effect of the magnetic field on the efficiency of quercetin oxidation was confirmed by the results of impedance spectroscopy measurements.

Graphene oxide activation with a constant magnetic field.

The effect of constant magnetic field strength on activation of sensors modified with graphene oxide monolayers was investigated. The use of constant magnetic field resulted in improved electroanalytical properties of the sensors. It was proven that level of GO activation is clearly related to constant magnetic field strength. Moreover, it was demonstrated that observed phenomenon is stable in time.