Silica gel is an amorphous adsorptive substance with stable chemical properties and has a highly complicated porous structure. It is odorless, tasteless, and non-toxic, and offers an excellent capacity for physical and chemical dehumidification because of good absorbability, chemical stability, wide surface area and higher mechanical strength. Therefore, silica gel is used for packing food, pharmaceuticals, goods for export and precision instruments. Silica gel is easy to handle and silica gel saturated with moisture can be regenerated to offer new moisture protection by simply reheating under specified condition.
Q: How are desiccants best used? Q: Who are our customers? No, silica gel isn't a gel like a hair gel. It is a solid material that comes in granular or beaded forms. These granules or beads are sorted according to their size. For silica gel in sachets, the grain size is not usually important, but for uses such as drying flowers, a fine grain silica gel is more suitable than a large grain silica gel. The larger grain sizes are suited for dynamic drying applications where air is dried by being passed through a bed of silica gel.
Q: But, does silica gel get wet as it adsorbs water? No it doesn't, one tremendous asset of silica gel is that it traps water molecules inside its pores yet remains totally dry and appears physically unchanged. It does not swell or change shape. Q: So, silica gel is a desiccant then? Yes, it adsorbs water vapor by physical means, not a chemical reaction. Water vapor is attracted inside the silica gels crystalline structure. Q: So, does silica gel now come in many colors?
Yes, now it does. Silica gel comes in either non-indicating or self-indicating forms. Non-indicating silica gel is white and stays white as it adsorbs moisture. Self-indicating silica gels have traditionally been impregnated with a moisture sensitive cobalt chloride indicator.
This gives a blue silica gel, which slowly changes color as it adsorbs moisture until it becomes pink. New self-indicating silica gels feature a number of other colors because they have different moisture sensitive indicators , but all have the same purpose to indicate when the silica gel is saturated and unable to take up any more moisture.
It is technically a xerogel but gets shortened to gel even though it is hard, just to confuse people. Water molecules stick to its surface, which is called adsorption. The similar-sounding phenomenon of absorption, involves the material being chemically incorporated into the material itself. Each silica bead has many tiny interconnected pores, resulting in high surface area. The tiny pores also hang on to moisture through capillary condensation, which means that, even when saturated with moisture, the beads seem dry.
Fancier types of silica gel contain other chemicals that change colour when they are saturated with moisture. The silica gels work best when in a sealed container, and the beads themselves are in a breathable bag. But, in the case of the seaweed silica packet, the wrapping seemed to be plastic, which didn't seem right, so I put it in water.
The water and it did not seem to pass through to the silica. This makes me wonder how useful it really was. I then repackaged seaweed into two resealable bags and had one with the silica gel and one without. A day later, they both seemed fine, so that did not really tell me much. White silica gel is a non-indicating silica gel.
It means that when the silica gel adsorbs moisture, it will continue to be white. This kind of silica gel is commonly used in packet.
White silica gel is a kind of gel you find in the small packets when you buy some products. Blue silica gel has cobalt chloride, which allows the blue silica gel change its color to pink when it reached its maximized adsorption capacity. Once pink it can be reactivated with heat to dry out the moisture. Do not use blue silica gel around food since the cobalt chloride is poisonous. Orange silica gel has methyl violet which is capable of changing from orange to green, or orange to colorless.
It is also toxic and potentially poisonous, even though it does have some medicinal merits. Like blue silica gel, once the color changes to indicate maximum adsorption, it can be reactivated with heat to dry out the moisture. Any product that will damage with high humidity such as leather, vitamins and electrical goods may have silica gel within the packaging. Drying processes like flower or seed preservation might also include silica get desiccants.
Call or email us to find out which is the best silica gel for your humidity problem. Silica Gel Desiccant Silica Gel is used in protecting goods against excess moisture, which can promote the growth of mold, spoilage and corrosion.
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