A New System of Sustainable Silico-Aluminous and Silicate Materials for Cultivation Purpose within Sustainable Buildings: Chemical-Physical, Antibacterial and Cytotoxicity Properties

In this study, we compared the chemical-physical, antibacterial, and cytotoxicity properties of silico-aluminous and silicate materials for outdoor (green roof, planted walls) and indoor (urban farms, indoor microgreen gardens) cultivation purpose in a context of sustainable construction. Glasses and lightweight aggregates were tailored starting from waste, by-product, and post-consumer and bioproducts (packaging glass cullet, cattle bone flour ash, vegetable biomass ash, spent coffee ground, degreased from biomass of prepupae of Black Soldier Flies) mixed together with a national ferruginous red clay, quarry scrap pumice and, if necessary, with K2CO3 of reagent grade. The first type of material was obtained by melting at 1200 °C and the second one by powder sintering at 1000 °C. All specimens, subjected to antibacterial test, showed both low zone of inhibitions towards two Gram-negative and two Gram-positive bacterial strains. A cytotoxicity test on mouse embryonic fibroblast NIH-3T3 cell line directly exposed to the investigated materials was performed at three different exposure times (1 h, 3 h, and 6 h). Data acquired highlighted that the materials positively affected redox mitochondrial activity of the fibroblast cells. The concentrations of leachate heavy metals detected on selected materials in water at room temperature after 24 h were lower than the European law limit and an interesting release of P, K, and N nutrients was noted for those formulations designed for agronomic purposes. pH, falling on average within the 6.5–7.5 range, is optimal for most crops, and the specific conductivity <2 dS/m indicates no depression danger for crops. Both bulk density <1200 kg/m3 and porosity over 50% seem to ensure good performance of lightening, drainage, water reservation, and oxygenation of the roots.

Discovering formation of ice 0 by low-frequency measurement data

In this work, low-frequency characteristics of wetted nanoporous silicate materials were measured, as well as the specimen’s own low-frequency electric fluctuations at the frequencies of 1…100 Hz. The measurements at low frequencies were conducted at different voltages of the probing signal. A capacity cell was used in making the measurements. In the experiments, at the temperatures below –25…–30 °C, non-linearity of the medium was discovered. The experiments on the study of the specimen’s own electric fluctuations at these temperatures revealed their essential increase. These temperatures are below the point of phase transition of supercooled water to recently discovered ferroelectric ice 0. Based on the measurements made, a conclusion was made regarding formation of this modification of ice in the nanosize pores of the wetted materials under study. Ice 0 is a ferroelectric; therefore, its formation from deeply supercooled water may have a significant impact on the electric parameters of wetted bodies at the temperatures below –23 °C. At the interface of such ice with another dielectric, a thin layer with practically metallic conductivity emerges. Such a layer influences not only the non-linear dependence of dielectric permittivity on the electric field but also increases attenuation of electromagnetic radiation in a medium.

Potential Landscape of a Probe Penetrant Particle for Fast Estimating of Silica Diffusion Properties

Successful search for optimal molecular structures of membrane materials requires efficient algorithms for assessing their diffusion properties. It is shown in this work that the potential landscape of a probe penetrating particle, a component that passes through the membrane during gas separation, is suitable for solving such problems. A number of indicators are considered that can be easily calculated from potential landscapes of specific models of silicate materials, both not related to the topology of the potential landscape (global minimum, voxel energy distribution), and depending on it (percolation cluster). A good correlation of these indicators with the corresponding diffusion coefficients is shown

The Possibility of Using an Infrared Spectrometer for Determination of Historical Building Material Composition

This paper deals with the possibilities of analysis of building materials in terms of chemical composition. Using the method of infrared spectroscopy, we can determine the organic compounds in coatings, adhesives, grout, and silicate materials. Building material characteristics have to be in accordance with the standards. However, due to external conditions, the material can degrade during its life. Observations and chemical analyses of the building materials must be performed to be able to do remediation and reconstruction of the historical building. Infrared spectroscopy was chosen as the best for qualitative analysis of organic admixtures in building materials.

Investigation of the Effect of Combined Binder Based on Portland Cement and Lime on the Properties of Non-Autoclave Silicate Materials Modified with Synthetic Crystalline Filler

Among the wide variety of currently used wall building materials and products, it is possible to single out the autoclave-hardened silicate products. To obtain silicate materials of autoclave hardening, lime-silica binders are mainly used. The hardening process of such a binder is carried out in an environment of water vapor at high temperature and pressure. It is relevant to use a certain type of silicate materials in the technology with raw materials that provide hardening with reduced parameters of hydrothermal synthesis, which will make it possible to obtain wall silicate materials in non-autoclave conditions. This can be done through the use of clay rocks of the mineral formation unfinished stage. In the course of the research, the effect of a combined binder based on Portland cement and lime on the properties of non-autoclave silicate materials modified with a synthetic crystalline filler was studied. It has been established that the addition of a synthetic crystalline filler represented by artificial calcium hydro-silicates makes it possible to increase the presence of a crystalline phase formed due to the clinker minerals hydration in the early stages of hardening, and, as a consequence, to increase the operational properties of the resulting composites. The addition of lime to the raw mixture will additionally compensate for the lack of calcium ions during the entire hardening process of non-autoclave silicate composites based on aluminosilicate raw materials and Portland cement.