Papers by Keyword: Water Glass

Abstract: The main objective of the present study was to investigate the application of Box–Behnken design which is a type of optimization design of response surface methodology (RSM) to predict and optimize some aging condition of magnesium silica aerogel (MSA) for improving surface properties such as surface area, pore volume and pore size. Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) techniques, tap density method and helium pycnometer were used to characterize aerogels. The operating conditions were optimized as a function of the molar ratio of Mg:Si (0.35, 0.50 and 0.65), aging time (24 h, 60 h and 96 h) and aging temperature (50 oC, 70 oC and 90 oC). Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for all three properties. Optimized aging factors for synthesis MSA with high BET surface area, high BJH pore volume and average BJH pore size were found to be 0.5 Mg:Si molar ratio, 79.62 oC and 61.51 h, respectively. Under these conditions, magnesium silica aerogels have great properties: 734 m².g^-1 BET surface area, 0.41 cm³.g^-1 BJH pore volume and 4.91 nm BJH pore size, 0.12 g.cm⁻³ density and 95 % porosity. Box-Behnken is useful optimization tool for production of nanoporous magnesium silica aerogel.

Abstract: How to extend your lifetime before you start using it or more often during use is a matter for every investor. In this paper, we will try to assess whether the use of protective coatings on concrete floors has a positive effect on the service life. The referee in our case will be the highly abrasive test method Böhme, which determines abrasion resistance. For comparison, we chose coatings based on sodium silicate solution, ie water glass. The market for these protective coatings is very diverse, so we have chosen to select products of renowned and unknown producers in different price ranges to cover the widest possible market.

Abstract: The properties of “water glass – graphite microparticles” composite material (CM) have been researched and qualitative and quantitative phase analysis of the CM structure has been done. Experimental samples of the CM with filler particles (graphite) and a few micrometers in size have been studied with X–ray diffraction and electron microscopy. Fire–resistance test of the composition has been conducted. Fire–resistance limit for the test samples of composite material is determined by the loss of its insulating ability (I). Fire–resistance limit I15 equal to 15 minutes has been obtained in accordance with the requirements of regulatory documents. It is shown that the research material is characterized by thermal stability and maintains its composition and structure under high temperature exposure. Composite material with the obtained characteristics can be used as protective coatings for building structures to increase fire resistance and reduce fire hazard.

Abstract: The article provides an overview of manufacturing a binding agent via combined grinding a silicate lump and calcium chloride. The data on the mineralogical composition of a mechanically activated binding agent are presented. The paper also describes composition and properties of putty on the base of a modified binding agent, which is intended for interior finishing operations in buildings.

Abstract: In the present paper, water glass was used to synthesize silica aerogels and calcium magnesium silica aerogels. The present research was aimed to investigate the effect of gel aging time (1 and 24 hours) on the physical and surface properties of aerogels. Brunauer-Emmett-Teller, Barrett-Joyner-Halenda, Fourier Transform Infrared spectroscopy and scanning electron microscopy techniques were used to characterize aerogels. Successful formation of nanopores (2.8-4.4 nm) was approved by N₂ adsorption/desorption isotherms. The aerogels contained porous network structure with different surface areas (388.9-729.9 m² g^-1). Aging for longer times led to an ability to decrease the density of the aerogels. The bulk density was higher in silica aerogels than in calcium magnesium silica aerogels. The well-tailored network matrix with high BET surface area (729.9 m² g^-1) and low density (0.116 g cm^-3) was achieved via 24 hours gel aging of calcium magnesium silica aerogel.

Abstract: The issue of natural fibers used for the production of materials with thermal insulation properties is its high moisture sensitivity and susceptibility to biodedgradaci. Effective protection of these fibers may be for some applications so. Mineralization which involves the application of inorganic compounds / binder to the surface of natural fibers. The paper focuses primarily on ways of implementing the mineralization using inorganic binders, and then changes the properties of natural fibers after application of various types of inorganic binders.

Abstract: This paper contains the continuation of basic research from 2012 - the molar ratio influence to water glass coatings basic properties (adhesion, diffusion properties, surface quality) was expanded with basic resistance (combination of sun, UV light and rain). Most silicate coatings for concrete protection are currently based on potassium water glass. Water glass matrix itself is, however, insufficient for coatings matrix and often is modified by polymer substances for the coating purpose. Combinations of water glass basic matrix (Sodium, Potassium, Lithium, Sodium - Lithium and Potassium - Lithium) with the appropriate polymer modifiers is also content of the presented paper. Polymer dispersions modification effect to basic properties and resistance to developed silicate coating binder is also part of paper.

Abstract: Sodium silicate, usually known as water glass, is researched as material that can potentially find use in composition of cement based matrix in order to improve its porous structure and related physical parameters. The water glass is applied in cement paste mixture in an amount of 5, 10, 15, and 20 mass% of cement. The water dosage is experimentally accessed in order to attain the same workability of particular mixtures. For the applied water glass and cement, the particle size distribution is measured on laser diffraction principle. Pozzolanic activity of water glass is investigated using modified Chapelle test. The particular studied cement pastes are cured 28 days in water and characterized by basic physical and mechanical properties, whereas the results of mechanical resistivity are supported by pore size distribution data accessed by mercury intrusion porosimetry. Althought the particles of applied water glass are coarser than that of cement and did not exhibit pozzolanic activity, their application partially tightened the porous structure of hydrated products and thus contributed to the mechanical strength by means of filler effect. This makes good prerequisites for future research that will be focused on a development of new types of cement-based composites with incorporated sodium silicate used as an modifying admixture.

Abstract: The paper discusses approaches to compositional build-up of high strength alkali activated cements made using water glass as alkaline activator represented by commercial products in a form of powder and liquid. The purpose was to study the influence of fineness of ground granulated blast-furnace slags, admixtures and additives, compatible with alkali activated cements, water glass and mode of manufacturing technology in order to reach high compressive strength (≥ 80 MPa at standard age (28 days)) and early strength (≥ 20 MPa after 3 h of hardening in normal conditions).

Abstract: These are many factors that can influence the properties of alkali-activated slag cementitious material, such as the modulus and content of water glass, water-cement ratio, curing conditions, and so forth. The rules that how these factors affect setting time and strength of the material are systematically discussed in the paper. It is found that the setting time of the material depends on the concentration of alkaline ions in solution; The material will have the best strength when the modulus and content of water glass are 1.4 and 8%, respectively. The curing temperature increase will be helpful to compressive strength increase.