Study on the Electrical Conductivity of Inorganic Conductive Network in Sediments

The inorganic conductive network provides an essential channel for electron transport and supports the biogeochemical process in sediments, but the conductive mechanism of conductive network is not well understood. In this work, theory of circuit and electronics was applied to build a three-dimensional (3D) resistivity network simulation model for exploring the conductive mechanism and analysing the effect of the particle size on the conductive characteristic of inorganic conductive network. In order to simulate the real sediment environment, inorganic composites with silica (SiO2) particles as matrix using magnetite (Fe3O4) particles as fillers are constructed. The simulation results reveal that the electrical conductivity of these composites rises nonlinearly with the increasing volume fraction of conductive fillers, which is consistent with the percolation theory. Moreover, small-sized conductive particles or large-sized matrix particles are confirmed to exert a positive part in enhancing electrical conductivity of composites.

Hyaluronic-Acid-Based Organic-Inorganic Composites for Biomedical Applications

Applications of natural hyaluronic acid (HYH) for the fabrication of organic-inorganic composites for biomedical applications are described. Such composites combine unique functional properties of HYH with functional properties of hydroxyapatite, various bioceramics, bioglass, biocements, metal nanoparticles, and quantum dots. Functional properties of advanced composite gels, scaffold materials, cements, particles, films, and coatings are described. Benefiting from the synergy of properties of HYH and inorganic components, advanced composites provide a platform for the development of new drug delivery materials. Many advanced properties of composites are attributed to the ability of HYH to promote biomineralization. Properties of HYH are a key factor for the development of colloidal and electrochemical methods for the fabrication of films and protective coatings for surface modification of biomedical implants and the development of advanced biosensors. Overcoming limitations of traditional materials, HYH is used as a biocompatible capping, dispersing, and structure-directing agent for the synthesis of functional inorganic materials and composites. Gel-forming properties of HYH enable a facile and straightforward approach to the fabrication of antimicrobial materials in different forms. Of particular interest are applications of HYH for the fabrication of biosensors. This review summarizes manufacturing strategies and mechanisms and outlines future trends in the development of functional biocomposites.

Inorganic Composites Luminophors in Lithium-Borate Glasses with Rare-Earth Elements for White-Emitting Diodes

The paper describes the synthesis of novel luminescent composite system, based on lithium-borate glass matrix with addition of rare-earth elements and yttrium-aluminum garnet finely divided powder. The new chemical composition of glass has been selected, composite’s fabrication technology was developed, the temperature conditions of glass and luminophore sintering as well. The spectral characteristics of the obtained luminescent composites are measured, and chromaticity diagrams are considered. The radiation spectra showed a maximum of about 560 nm, the maximum spectral intensity of the radiation is about 90 μw/cm2/nm. Powerful energy saving source of white light was produced.

Imaging with Neutrons

By exploiting the penetration, attenuation, and scattering properties of neutrons, images of matter in two or three dimensions reveal information unobtainable using other probes. Despite the limitation in brilliance of neutron sources, several neutron-based imaging techniques are essential to different aspects of modern geoscience. Typical examples include the evaluation of porosity in rocks and sediments, mapping of light elements in solids, noninvasive probing of cultural heritage objects, investigations of thick engineering components, and the exploration of diffusion and percolation processes of fluids within porous matrices, organo-inorganic composites, and living organisms. Techniques under development include simultaneous neutron and X-ray tomography in heterogeneous media, Bragg-edge imaging, and the possibility of porosimetry from dark-field imaging.

Magneto-sensitive Carbon-inorganic Composites Based on Particleboard and Plywood Wastes

The conversion of metal-modified (Fe, Co) sawdust into magneto-sensitive porous composites using thermal carbonization process in an inert atmosphere was successfully achieved. The as-prepared samples were characterized using nitrogen adsorption, X-ray diffraction, scanning electron microscopy and thermal analysis methods. The obtained results show that the structural and morphological characteristics of the obtained composites depend strongly on the metal precursor’s types. All samples exhibited a good magnetic property and can be easily separated from liquids by an external magnet.