Sodium silicate, known as liquid glass, the use in the construction of which, as in many other fields, has become the norm, is a chemical compound of sodium oxide (Na 2 O) and silicon dioxide (SiO 2 ). As a result, a glassy substance is formed with a very useful property of solubility in water, so that the material can take the form of either solid crystals (or powder) or a syrupy brownish liquid.
Crystals born on fire
The production technology of the material is a process of calcining soda ash and silica sand in a furnace at a temperature of 1000 to 1400 ° C. As a result of this, carbon dioxide is released and sodium silicate (Na 2 SiO 3 ) is formed.
Possible forms and types of sodium silicate
To the final consumer, this silicate compound can be realized both in the initial form of large glass crystals and in the form of ground powder. To obtain liquid sodium glass, reactors are used where solid silicate particles are dissolved in hot water under pressure. After cooling, the finished product, having the form of a viscous liquid, is Packed in containers of various volumes. Liquid sodium silicate can also be obtained by directly dissolving silica sand under pressure in a heated aqueous composition of caustic soda.
With any production technology, the finished solution will be the more viscous, the higher the concentration of its constituent elements. High viscosity liquid glass is used to form glass granules obtained by spraying and drying a hot solution. The resulting beads are packed and shipped in the same way as the solid form of sodium silicate, but (unlike anhydrous compositions) they dissolve several times faster, greatly simplifying the process of applying the material.
Fire, water and water pipes
Let's look at what makes this product so special. High alkalinity, corrosion resistance, excellent bonding ability in combination with natural (read: safe) components are the main properties of water glass, its application is fully based on the use of these unique qualities. Products and surfaces treated with sodium silicate acquire moisture resistance, heat resistance, protection against fungus and bacteria, and compositions based on it are used for sealing and corrosion protection of metal plumbing connections.
Liquid armor
The use of water glass in the repair and construction works is very effective and appropriate for a number of reasons. Concrete as the main building material is most susceptible to all kinds of aggressive influences, both operational and natural in nature, because its protection and strengthening is almost the main "headache" of any homeowner. It is to solve this difficult task that sodium liquid glass can serve. Its use as an additive in concrete mortar or plaster mix comprehensively affects the consumer characteristics of the building material:
- Due to the high adhesion, the surface strength of concrete increases, reducing the risk of microcracks.
- The refractoriness of sodium silicate gives the structure high heat resistance, which makes it possible to successfully use materials and solutions based on it for the construction of stoves and fireplaces.
- As a result of a decrease in the porosity of the concrete mortar, the corrosion resistance of all elements containing liquid glass against moisture, temperature extremes, and other natural influences is greatly increased.
- Concrete acquires bactericidal properties.
When choosing improving additives, these factors, combined with the low cost of the material, make liquid glass attractive.
For concrete, the instruction for use from the classical composition (3 parts of sand, 1 - cement) differs only in that a certain amount of liquid sodium sulfate is added to the finished sand-cement solution (approximately 20% of the volume of the dry mixture).
Fly in the ointment in a barrel of viscous brownish substance
The only serious drawback of using such an additive is a significant reduction in the solidification time of concrete. Therefore, they use this technology in small areas (for example, for laying refractory bricks in the construction of stoves and fireplaces) or they calculate the volume of the mix so that the concrete does not have time to set. For this reason, many builders often use a different use of liquid sodium silicate.
Raincoat for concrete
This method is based on the characteristics of the material to form a monolithic film after drying. This property (together with hydrophobicity and high adhesion of the composition) determined its active use in protecting buildings and structural elements from moisture by direct application to the treated surface, that is, priming.
Why, among the many ways and types of waterproofing, it is worth paying attention to liquid glass? Concrete application compares favorably with its competitors in a number of ways:
- Simplicity and speed of drawing. For work it is enough to have a wide paint brush, spatula or spray gun.
- High adhesion. After application, the material does not peel off, firmly bonding to the base.
- High fluidity. Qualitatively covers all cavities and microcracks.
- Antiseptic treatment. The surface becomes invulnerable to fungus and mold.
- High environmental friendliness of the binder material. Allows the use of liquid glass inside residential premises. Being non-toxic and one of the most common chemical compounds in nature, sodium silicate has no harmful effects on the environment. Ultimately, it returns to its natural state in the form of silica (SiO 2 ) and soluble sodium compounds.
- In addition to improving moisture protection properties, the surface layer is strengthened as a result of processing, which increases the wear resistance of the base and serves as a protection for the decorative coating.
- Economical material consumption.
- Affordability and economical cost.
Clinging to everyone, does not allow to pester
Before processing, it is necessary to thoroughly clean the surface from debris and dust, and plaster large cracks and chips. With a single application, the concrete screed is reliably impregnated with liquid glass to a depth of two to three millimeters. Recoating with the composition is carried out only after solidification of the previous layer. After several treatments, impregnation of the base material up to twenty millimeters can be achieved.
The disadvantage (or features of this coating) is the impossibility of painting or pasting after application. The smoothness of the surface, as well as the high temperature and chemical stability of sodium silicate prevent the diffusion of third-party solvents into its internal structure.
Ideal proportions depend on the desired result.
For construction work, there are several ways to use liquid glass. Instructions for use for each of them have their own characteristics:
- The solution for waterproofing consists of one part of liquid glass and two parts of water. With this proportion, about 300 ml of the resulting composition is left on the 1m 2 coating.
- The primer is used for preliminary preparation before wallpapering or painting. In this case, cement previously mixed with water is mixed with liquid glass in equal proportions.
- In the manufacture of waterproofing plasters, a sand-cement mixture with a silicate additive is prepared in equal proportions of all ingredients (1 x 1 x 1).
- An antiseptic solution is created by mixing water and water glass in equal proportions.
Unusual features of unusual glass
The alkaline properties of sodium silicate, which help to remove fats and oils, neutralize acids and decompose starches and proteins, make it ideal for use in one of the most common consumer products: detergents for washing and dishwashers.
Small amounts of water glass are used for wastewater treatment, where it adsorbs metallic ions and helps in the formation of loose particles, filtering water from unwanted suspended materials.
The solid version of sodium silicate is widely used to make silica gel, a commonly used drying agent.
This is a great glue for glass or porcelain.
The traditional use of water glass is its use as a preservative for eggs, which in cool conditions can be stored for several months in a viscous silicate solution.
Liquid sodium silicate is added to the automobile radiator to seal the engine head.
There are many variations of silicate compounds in which sodium is replaced by other alkali metals, for example potassium or lithium. Each of them is suitable for its needs, but they all have the same property of being a glassy solid, which dissolves in water to form an alkaline solution.