Catalytic Action of Nitric Acid on The Hydrolysis of ETS-40 Ethyl Silicate

The effect of concentrated nitric acid on the hydrolysis rate of ETS-40 ethyl silicate hasbeen studied. The duration and maximum temperature of ethyl silicate hydrolysis at different temperatures of the components have been determined. The formation of silica particles in the xerogel structure is shown. The influence of the ETS-40 hydrolysis on the particles size and concentration has been examined. The structure of the xerogel and the composition of the formed particles have been investigated using scanning electron microscopy (SEM) and energy dispersion analysis (EDX).

Investigation of Gas Formation Processes in Cotton Fabrics Impregnated with Binary Compositions of Ethyl Silicate - Flame Retardant System

The use of complex fire-retardant coatings based on ethyl silicate gel - diammonium hydrogen phosphate reduces the process of smoke formation during thermal exposure to treated tissue samples, which is promising for improving the fire safety of textile materials. The compositions are easy to obtain, they do not require specific processing conditions, do not contain toxic substances. This allows us to offer developed compositions for fire protection of textile materials used in facilities with a large number of people.

Polymer Binders of Ceramic Nanoparticles for Precision Casting of Nickel-Based Superalloys

This study presents the general characteristics of binders used in precision casting of Nickel-based superalloys. Three groups of binders were described: resins, organic compounds, and materials containing nanoparticles in alcohol or aqueous systems. This study also includes literature reports on materials commonly used and those recently replaced by water-soluble binders, i.e., ethyl silicate (ES) and hydrolysed ethyl silicate (HES). The appearance of new and interesting solutions containing nano-alumina is described, as well as other solutions at the initial stage of scientific research, such as those containing biopolymers, biodegradable polycaprolactone (PCL), or modified starch. Special attention is paid to four binders containing nano-SiO2 intended for the first layers (Ludox AM, Ludox SK) and structural layers (EHT, Remasol) of shell moulds. Their morphology, viscosity, density, reactions, and electrokinetic potential were investigated. The binders were characterized by a high solid-phase content (>28%), viscosity, and density close to that of water (1–2 mPa·s) and good electrokinetic stability. The nanoparticles contained in the binders were approximately spherically shaped with an average particle size of 16–25 nm.

Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

Consolidation tests in archaeological wall painting: comparing treatments depending on the painting technique

Consolidation is a treatment of great importance for archaeological wall paintings due to their state of preservation, in which the lack of cohesion of the mortar and the pulverulence of the pictorial layer are common. The objective of this work has been to evaluate consolidation tests that have been carried out on decontextualized fragments belonging to five different wall paintings (from different periods and with differences in their state of conservation and in their painting techniques). For this, two of the most used treatments in consolidation of archaeological coatings, such as an acrylic resin and ethyl silicate, have been compared with two treatments that use nanoparticles, such as nanolimes and nano ethyl silicate, together with a bioconsolidation treatment used until present mainly for the consolidation of stone material: bacterial carbonatogenesis.

Influence of different surface treatment on water penetration resistance of concrete

Concrete is easily affected by all kinds of erosive substances during its use. Surface treatment is a simple method to improve the surface compactness and water permeability resistance of concrete. In this paper, silicate infiltration agent, nano-SiO2 and ethyl silicate are selected as concrete surface treatment material. The results of water permeability test showed that all the three treatments can effectively improve the water resistance. Silicate infiltration agent and nano-SiO2 were the most effective, which greatly reduced the penetration depth of water from 66 mm to 34mm and 32 mm, while ethyl silicate was reduced to 50 mm. Through the water permeability test curve, we can see that the water entered the concrete under a certain pressure, and the result showed the shape of high, middle and low edge.

Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO2 Activated by Either UV-A or UV-B Radiation

This study evaluated the self-cleaning ability and durability of Si-based consolidants (an ethyl silicate consolidant and a consolidant based on nanosized silica) spiked with nanocrystalline TiO2 activated by either UV-A radiation (spectral region between 340 and 400 nm, and main peak at 365 nm) or UV-B radiation (spectral region between 270 and 420 nm, and main peak at 310 nm). Granite samples were coated with consolidant, to which nanocrystalline TiO2 was added at different concentrations (0.5, 1, and 3%, by wt.). Diesel soot was then applied to the coated surfaces, and the samples were exposed to UV-A or UV-B radiation for 1650 h. The surface color changes, relative to the color of untreated granite, were determined every 330 h by color spectrophotometry. Slight color changes indicated a recovery of the reference color due to the degradation of the soot. The final surfaces of both the untreated and treated surfaces were compared by stereomicroscopy and scanning electron microscopy. The main findings were that: (1) In general, the consolidant containing nanosized silica induced the most intense photocatalytic activity. In the more compact xerogel coating formed by the nanosized silica, more TiO2 nanoparticles were available to interact with the radiation. (2) For all consolidant mixtures, soot degradation remained constant or decreased over time, except with ethyl silicate with 0.5 wt % TiO2 (no self-cleaning capacity). (3) Soot degradation increased with the concentration of TiO2. (4) The UV-B radiation was the most effective in terms of soot degradation, except for the surface coated with the ethyl silicate and 3% wt. TiO2.

Low Temperature Glass Sintering Based on Silico Sodium Resins

By using silicate inorganic binders and glass waste it is possible to mould technical and artistic elements which later can be compacted by means of low temperature, and subsequently apply the sintering through high-temperature processing, which is generally lower than current melting glass processes, close to 1250 °C. The experimental phase established thermal ranges from 600°C to 750°C, a fact that allows for an effective sintering temperature (of around 650°C/18 hours). The mixtures and proportions for this experiment were fixed including ethyl silicate as a fluidizer in mixtures,as well as the size of glass grains.The results indicate good compaction of the samples after the initial phase (80°C/24h), allowing proper handling without alterations in samples edges.During heating treatment, mechanical resistance increases gradually (600-750°C), although the volume of porosity was inversely proportional. According to the matrix vs grain size relationship, the partial fusion of both materials is evident in the rounding of the glass grains as well as the resin bonds joined between them. The resins appeared in a homogenous fashion, covering and gluing the grains, a development which improves the joining of sintered samples. Samples with a mixture of sodium silicate and ethyl silicate resins experienced less melting between grains due to a lower volume of fluxing elements, which means a lower percentage volume of sodium (Na). This study concludes that a sintering process for new vitreous composites could be carried out between 650°C and 700°C, offering the opportunity for a substantial reduction in the amount of energy required to produce industrial glass. Keywords: Water-glass, glass recycling, low temperature