Mathematical Modeling of Electrical Conductivity of Anisotropic Nanocomposite with Periodic Structure

Composite materials consisting of a dielectric matrix with conductive inclusions are promising in the field of micro- and optoelectronics. The properties of a nanocomposite material are strongly influenced by the characteristics of the substances included in its composition, as well as the shape and size of inclusions and the orientation of particles in the matrix. The use of nanocomposite material has significantly expanded and covers various systems. The anisotropic form of inclusions is the main reason for the appearance of optical anisotropy. In this article, models and methods describing the electrical conductivity of a layered nanocomposite of a self-similar structure are proposed. The method of modeling the electrical conductivity of individual blocks, layers, and composite as a whole is carried out similarly to the method of determining the dielectric constant. The advantage of the method proposed in this paper is the removal of restrictions imposed on the theory of generalized conductivity associated with the need to set the dielectric constant.

Facile Synthesized Novel Nanocomposites Modified Electrodes in the Trace Detection of Sulfamethoxazole

Micro-pollutants, especially antibiotics contamination in water bodies, are a serious concern, and their detection at a low level is important for human health and even aquatic life at large. The present investigation aims to obtain the novel nanocomposite material precursor to clay and silane. The nanocomposite material is decorated with Ag or Au nanoparticles as obtained indigenously by a green route using natural phytochemicals. The materials were extensively characterized by advanced analytical methods. The nanocomposite materials (Ag(NP)/TCBN and Au(NP)/TCBN) are employed in the selective and efficient trace measurement of sulfamethoxazole (SMZ) in aqueous solutions using the differential pulse anodic stripping voltammetry. The cyclic voltammetric and electrochemical impedance spectroscopic methods showed an increased electroactive surface area as well as faster electron transfer reactions compared to the glassy carbon electrode (GCE). The DPASV measurements at the concentration range of 0.25 mg/L to 30.0 mg/L showed that the novel nanocomposites provide the LOD of 0.022 and 0.036 mg/L, respectively, for the Ag(NP)/TCBN/GCE and Au(NP)/TCBN/GCE for sulfamethoxazole. Further, the application of the method for the detection of sulfamethoxazole in real water samples resulted in an acceptable recovery percentage of 93.08 to 103.7.

A Novel Biodegradable Composite Polymer Material Based on PLGA and Silver Oxide Nanoparticles with Unique Physicochemical Properties and Biocompatibility with Mammalian Cells

A method for obtaining a stable colloidal solution of silver oxide nanoparticles has been developed using laser ablation. The method allows one to obtain nanoparticles with a monomodal size distribution and a concentration of more than 108 nanoparticles per mL. On the basis of the obtained nanoparticles and the PLGA polymer, a nanocomposite material was manufactured. The manufacturing technology allows one to obtain a nanocomposite material without significant defects. Nanoparticles are not evenly distributed in the material and form domains in the composite. Reactive oxygen species (hydrogen peroxide and hydroxyl radical) are intensively generated on the surfaces of the nanocomposite. Additionally, on the surface of the composite material, an intensive formation of protein long-lived active forms is observed. The ELISA method was used to demonstrate the generation of 8-oxoguanine in DNA on the developed nanocomposite material. It was found that the multiplication of microorganisms on the developed nanocomposite material is significantly decreased. At the same time, the nanocomposite does not inhibit proliferation of mammalian cells. The developed nanocomposite material can be used as an affordable and non-toxic nanomaterial to create bacteriostatic coatings that are safe for humans.

Synthesis of nanocomposite material through modification of graphene oxide by nanocellulose

Intensive research of nanocomposites contributes to the development of new materials in the fields of medicine, nanoelectronics, energy, biotechnology, information technology. Therefore, the synthesis of new materials by modifying of graphene oxide (GO) with nanocellulose and the study of its properties are of great interest. In this study synthesized nanocomposite material by modifying of graphene oxide (GO) from activated carbon (BAU-A) in a 1:1 volume ratio with nanocellulose (NC) from hemp stems belonging to the annual plant, and their chemical structure was studied by FTIR and UV-spectroscopy. The results of the study showed the absorption of the etheric bond C = O in the UV spectrum at full length 243 nm. The IR spectrum showed all the new etheric bonds O = C - OH at a wavelength of 1625 cm-1. The average particle sizes of GO was 352 nm and NC was 470 nm in length and 80 nm in width. The SEM analysis indicating the NC as a contact layer between ultralow thicknesses of the GO layers. The XRD analysis indicated GO-NC composite film is a substance comprising GO and NC. According to the results, modification of graphene oxide showed that its scope can be expanded as much as possible.

Study of the physical and biological properties of nanocomposite materials obtained with laser radiation

The new method of the formation of nanocomposite materials based on carbon nanotubes for the regeneration of connective tissues has been developed.Aim. Study of the structure, mechanical characteristics and biocompatibility of the obtained materials.Materials and methods. The experimental samples of nanocomposite materials were based on multi-walled and singlewalled carbon nanotubes, the matrix was bovine serum albumin. A layer of liquid dispersion of the components on a silicon substrate or in a container was irradiated with laser radiation to form the solid nanocomposite material. The microstructure of the obtained samples was analyzed with X-ray microtomography, the tensile strength was investigated using a testing machine. Fibroblast cells were incubated with experimental samples for 3, 24, 48, and 72 h and then fixed with glutaraldehyde. Cell growth during incubation with samples was studied using optical and atomic force microscopy.Results. It was found that a slight decrease in tensile strength and increase in the degree of deformation were observed with an increase in the concentration of carbon nanotubes. At the same time, the mechanical parameters of the samples corresponded to the requirements for materials for the restoration of connective tissue defects. Microscopic studies indicate good adhesion of cells to the nanocomposite material, no toxic effect of the samples on the cells was found. After 3 hours of incubation, the cells had their original rounded shape, after 24 hours of incubation cells began to proliferate on the sample’s surface and were spindle-shaped. After 48 and 72 hours, the cells practically formed a monolayer on the surface of the samples.Conclusion. The results of the study show that the structural and mechanical parameters of the developed nanocomposite materials meet the requirements of biomedicine. It was also shown that nanocomposite materials do not suppress cell growth and can serve as a scaffold for the regeneration of damaged tissues.