What is silica gel?

Silica gel is a granular, transparent and porous form of silicon dioxide, which is artificially obtained from sodium silicate. This substance is non-toxic, non-flammable, with low reactivity and stable.

Silica gel is usually used in 2 x 3 cm packages as a desiccant and dehumidifier to prevent the damaging effects of moisture or liquids in the deterioration of some products. You have often seen in the boxes of bags, shoes, electronic and computer equipment, cameras, clothes, medicine and various tools.

Since they usually add other chemical compounds to silica gel for greater absorption power, you will encounter the warning “DO NOT EAT” on its packages.

Silica gel is a three-dimensional polymer consisting of tetrahedral units of silicon dioxide. This material is a porous material.

Silica gel is a good absorbent for water, alcohol, phenols, amines, etc., which does this through hydrogen bonds. The absorption capacity of silica gel at low temperatures is higher than that of alumina and zeolite, however, if the humidity is low, it shows less absorption than zeolite.

On the other hand, the regeneration of silica gel is easier and is possible by heating it up to 150 degrees Celsius, while zeolite must be heated up to about 350 degrees Celsius. Due to these properties, silica gel is used in environments where low temperature, moderate water vapor pressure, and high absorption capacity are required.

The use of silica gel in the maintenance of bags and shoes:

The use of silica gel in the maintenance of bags

• cosmetic bag

If you have liquid cosmetics that may leak inside the makeup bag, put a few packets of silica gel inside to prevent moisture from leaking inside the bag.

• sport bag

By putting a few packets of silica gel in your sports bag, prevent any unpleasant odor and moisture, because sports clothes get wet after exercise, and if you forget to take them out of the bag, both your clothes and your bag will smell bad. Prevent unpleasant odors by using silica gel.

• baggage

Suitcases are one of the things that are used only when traveling and otherwise they are unusable and we turn the suitcase into a small storage for our things.

It is often stored either underground or above the closet, and for this reason, they are not used frequently, so prevent moisture absorption and mold growth by placing a few packets of silica gel in the suitcase.

You can use silica gel in all your bags because the main function of silica gel is to absorb moisture and prevent the growth of mold and harmful fungi.

The use of silica gel in the maintenance of shoes

• walking shoes

Those who go for long walks or those who have to keep their feet in their shoes at work are always afraid of smelling their shoes, and we suggest that when you come back from a walk or work, put a packet of silica gel inside Leave your shoes on to absorb moisture and prevent bad odor.

• Leather shoes

There are probably several packets of silica gel in your leather shoe box. If you keep the shoes in their box, the silica gel will prolong the life of the shoes.

Types of silica gel:

Type A

Transparent pellets, approximate pore diameter: 2.5 nm, drying and anti-moisture properties, can be used as catalyst carriers, absorbents, separators and variable pressure absorbents.

B type

Transparent white pellets, pore diameter: 4.5 ⁠ -7.0 nm, liquid absorbents, desiccant and perfume carriers, also may be used as catalyst carriers, cat litter.

C type

Semi-transparent, microporous structure, raw material for preparing silica gel substrate. In addition, dried and sieved, silica gel forms pores that are used as desiccant carriers, adsorbents, and catalysts.

Alumina silica gel

Light yellow, chemically stable, flame resistant, insoluble except in alkaline or hydrofluoric acid. Surface polarity, thermal stability, higher performance than fine pore silica gel.

Stabilizing silica gel

A non-crystalline, non-toxic, flame-resistant solid powder, used in beverages to improve flavor, clarity, color, and foam, and to remove non-microorganism impurities.

Application of silica gel:

dryer

Silica gel is used as a protection tool to control relative humidity in exhibitions, libraries and museums.

chemistry

In chemistry, silica gel is used as a stationary phase in chromatography.

cat litter

Silica gel is used alone or in combination with more traditional materials such as clay as cat litter.

water refinery

Due to the water absorption properties of silica gel, it is used in household water purifier filters.

Transformer

Silica gel with indicator is also used in power line transformers, which is used as an oil strainer and dehumidifier in them.

Features of silica gel:

The high specific surface area of ​​silica gel (about 750-800 m2/g) allows it to absorb water easily, making it useful as a desiccant. Silica gel is often described as a “moisture absorbent”.

In this case, it may be suitable when ignoring the microscopic structure of the gel, such as silica gel packets or other products. However, the material silica gel removes moisture by absorbing the surface of its many pores instead of being absorbed in the bulk of the gel.

Its dangers:

• Silica gel is non-toxic, non-flammable and non-reactive and stable with normal use.
• This substance will react with hydrogen fluoride, fluorine, oxygen difluoride, chlorine trifluoride, strong acids, strong bases and oxidizing agents.
• Silica gel is irritating to the respiratory system and may cause irritation to the digestive system.
• Seed dust may cause skin and eye irritation, so precautions should be taken.
• Crystalline silica dust can cause silicosis, but synthetic amorphous silica gel is immersible, so it does not cause silicosis.
• Additional hazards may arise if the moisture indicator melts.