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At present, liquid silicone bracelets are very popular in the market. However, in order to save costs, some manufacturers have caused a large number of inferior silicone bracelets to flow into the market. Silicone bracelet.

Silica gel is a porous material with different particle sizes formed by dehydration of silicic acid gel mSiO2 · nH2O. It has an open porous structure, a large specific surface (surface area per unit mass), and can absorb many substances. It is a good desiccant, adsorbent and catalyst carrier. The adsorption of silica gel is mainly physical adsorption, which can be regenerated and used repeatedly.

Add acid to the alkali metal silicate (such as sodium silicate) solution to acidify it, and then add a certain amount of electrolyte to stir, that is, generate a silicic acid gel; or add acid to a more concentrated sodium silicate solution or Ammonium salts can also generate silicic acid gel. Silicic acid gel is allowed to stand for several hours to aging, then soluble salts are washed away with hot water, dried at 60-70 ° C and activated at about 300 ° C to obtain silica gel.

Dissolve the silicic acid gel with cobalt chloride solution, then dry and activate it to obtain discolored silica gel. When it is used as a desiccant, it is blue before absorbing water, and becomes red after absorbing water. From the color change, we can see the degree of water absorption and whether regeneration treatment is required. Liquid silicone bracelet silica gel is also widely used in steam recovery, petroleum refining and catalyst preparation.