Vadodara, Gujarat, India - Silica gel blue is free of any kind of moisture then it is very dark blue in color. As they absorb moisture, they start to change color from dark blue to lighter shades of blue. When these gels turn pink in color, need of replacement or regeneration is indicated. Similar is the case with silica gel orange. These also have indicators in them that are responsive to the change in the moisture levels around them.
Silica gel is basically an amorphous form of silicon dioxide. These are hard, irregular granules that are prepared synthetically. The basic reason behind the moisture absorption property of silicon is that it has porous surface. In these porous surface, no absorption takes place. The process that takes place is basically adsorption. The things that makes this adsorption possible is the difference in the relative humidity. The difference in the relative humidity level is what gives the pores the ability to store water in them. This ability stops when the state of equilibrium is reached, that is when the relative humidity at the pores of the gel and the atmosphere is equal. The self-indicating silica gel have a special chemical component added that is sensitive to humidity and changes color when exposed to different amounts of humidity. In the orange silica gels, an organic indicator is present that changes color from orange to green. They are used mostly in the form of dust. These gels are seen to absorb as high as 40 percent of their original body weights. They also have indefinite shelf life if they are stored properly in air tight containers. The best way of driving off moisture out of these gels is by gently heating them.
These beads find various applications in various industries. The most basic use is for the drying and cleaning of the air and gases. These beads find great use in any kind of a dehumidification process. Silica beads are also used in the drying of analytical sample as they don’t participate in any type of a chemical reaction. They are also used to protect the sensitive optical instruments and lenses from damage caused due to humidity.