Nanotechnologies in Construction: A Scientific Internet-Journal

20-38

Authors: Makeev A.I., Chernyshov E.M.

The dust fraction of the granite crushing screenings is considered and evaluated as a carrier of microsize and nanosized components engaged in the structure formation of cement stone and concrete. The genesis of the pulverized fraction and the identification of its composition and specific properties are given. The paper also analyzes the nature of mechanical, mechanochemical, physical and chemical activity and the role of the pulverized fraction of screening in the processes of cement hydration and structure formation of cement stone. The microsized component is regarded as a filler in the cement that is a part of the fine-grained concrete mixture. The nanoscale component is analyzed as a silica-containing additive capable to provide nanomodification of the hydrated cement structure. Experimental data and quantitative estimates of the influence of the dust fraction on the hardening dynamics and the strength of fine-grained concrete are presented.

75-100

Authors: Kudryavtsev P.G.

This paper is a continuation of our series of papers devoted to the production of ceramic and composite nanomaterials based on various inorganic heat-resistant binders. The work is devoted to important aspects that determine the properties of such materials: micro- and macrostructure, and the chemical composition. These factors are of particular importance for the production of porous, heat-resistant materials. In this paper, the main types of porous heat-resistant materials are considered. Porous materials are the solids that contain voids in a sufficiently large amount, and the average size of individual voids is significantly smaller than the body size. The structure of porous materials is characterized by the following parameters: general or true porosity, closed porosity, open or apparent porosity, average pore size and size distribution function, specific pore volume, specific surface area, the degree of the material anisotropy, permeability.

120-137

Authors: Baikov I.R., Smorodova O.V., Kitaev S.V., Yerilin I.S.

Nanotechnology is currently the main mega-project in science in general and particularly in energy. According to experts of the modern scientific world, it is possible to solve global energy problems only with the help of a convergent NBIC-technology complex. One of the directions of nano-optimization of energy production processes is the use of fuel cells. Fuel cells are sources of electrical energy that produce the minimum amount of greenhouse gases due to the high efficiency of direct conversion of the chemical energy of hydrogen, hydrocarbons and other types of fuel through the electrochemical oxidation reaction.The most promising types of fuel cells for energy are solid oxide fuel cells (SOFC); their features are high operating temperature and versatility in the types of fuel used. The high temperature of SOFC entails both positive and negative aspects, but it is very difficult to single out a certain optimal temperature range for a particular fuel cell without experimentation.

166-180

Authors: Artamonov V.Yu., Ganiev S.R., Ismakov R.A., Kuznetsov Yu.S., Pustovgar A.P., Sultanov D.R., Shmirkov O.V.

The paper presents the results of complex studies of influence of wave technologies on physical and mechanical properties of fine-dispersed montmorillonite suspensions in laboratory conditions at Research Center for Nonlinear Wave Mechanics and Technology Mechanical Engineering Research Institute of the Russian Academy of Sciences. It is shown that wave processing by means of hydrodynamic flow type generators with tangential and radial channels and flattype generators with cylindrical bodies of flow resulted in substantially increased dynamic shear stress, the number of particles in the 1–2 μm solution has grown 2.5 times. This means that the wave processing of the clay suspension leads to increasing of the colloid fraction, and, consequently, to improvement of the suspension quality, to decrease in the clay powder consumption, and also to several times reduced preparing time, compared to conventional technology. It is demonstrated that the main contribution to achieve high efficiency of wave processing is made by nonlinear wave and cavitation processes that run in the flowing part of hydrodynamic generators.