What is the Difference Between Desiccant and Silica Gel

The main difference between desiccant and silica gel is that desiccants are drying agents that attract moisture in the surrounding environment, whereas silica gel is a type of desiccant.

Earth is made of different chemical compounds. These chemical compounds are of different sizes, different masses, different shapes, and different properties. These differences are due to the differences in the chemical composition of compounds. Among the properties are combustibility, ductility, electric conductivity, heat conductivity, and moisture absorption. Desiccants are simply drying agents. The special chemical properties of desiccants make them attract moisture. In fact, this property makes desiccants a widely used commercial product to remove moisture in the surrounding.

Key Areas Covered

1. What is a Desiccant
      – Definition, Composition, Features
2. What is a Silica Gel
      – Definition, Composition, Features
3. Difference Between Desiccant and Silica Gel
      – Comparison of Key Differences

Key Terms

Desiccant, Silica Gel

Difference Between Desiccant and Silica Gel - Comparison Summary

What is a Desiccant

Desiccants are drying agents that attract moisture in the surrounding environment. Desiccants have a high affinity to water. They are the opposite of humectants, which promote the increase in moisture content of the surrounding. Desiccants remove humidity in the air. In addition to removing moisture, desiccants serve other purposes too. Desiccants are mostly available in the solid state. Some desiccants are liquids such as alcohol. They either absorb or adsorb water; hence they are hygroscopic materials. Additionally, desiccants are available in various forms. Some examples of desiccants include silica gel, activated charcoal, molecular sieve, activated alumina, charcoal sulphate, and calcium chloride.

Desiccants are generally chemically inert, meaning that they do not react with water or the substance they are to protect. They are sold in desiccant units. Desiccants are widely used in various industries and in day-to-day life. Some desiccants also absorb odor in addition to moisture.

Desiccant vs Silica Gel

Manufacturers commonly use desiccants in packages used in transportation and storage, especially to absorb moisture inside of the package. The usage of desiccants prevents corrosion of substances and microbial spoilage, such as mold growth, due to the reduction of humidity. Desiccants are also used in electrical appliances and circuits to prevent harm due to moisture. Sometimes they are used in sealants in insulated windows. Desiccants prevent the formation of hydrates of certain chemicals. Furthermore, some of the industries that use desiccants are the food packaging industry, industries that produce electrical equipment and appliances, industries that manufacture medical equipment, and the chemical industry.

What is Silica Gel

Silica gel is a combination of water and silica that is in the form of small pellets. Silica gel has many pores on it, which could retain and trap water molecules. But it does not fully absorb water. Water molecules are held onto the surface of silica gel. It has high adsorption properties. Moreover, silica gel is not an edible substance. If someone swallows silica gel accidentally, he or she should immediately go into an emergency room. Sometimes silica gel has a coating of cobalt chloride, which is very toxic. Hence, manufacturers only use food-grade silica gel packets for food storage.

Compare Desiccant and Silica Gel - What's the difference?

There are three groups of silica gel in terms of the value of density: regular, intermediate, and low density gels. Regular-density silica gels have high surface areas, whereas low-density and intermediate-density silica gels have comparatively low densities.

Furthermore, in commercial usage, silica gel is packeted in small packets and included in the storage boxes of electronics, clothing, food and baked goods, and leather.

Difference Between Desiccant and Silica Gel

Definition

Desiccants are drying agents that attract moisture in the surrounding environment, while silica gel is a combination of water and silica that is in the form of small pellets.

Nature of Absorption

Desiccants either adsorb or absorb water, whereas silica gel only adsorbs water.

Relationship

There are different types of desiccants as activated charcoal, molecular sieve, activated alumina, charcoal sulphate, and calcium chloride, while silica gel is one type of desiccant.

Composition

The chemical composition of desiccants varies according to the type of desiccant, whereas the chemical composition of silica gel is simply water and silica.

Conclusion

Different chemical compounds have different chemical properties. The ability to attract moisture is one of them. A desiccant is simply a dehydrant that attracts moisture from the surrounding vicinity. Meanwhile, silica gel is a type of desiccant that only adsorbs water. Thus, this is the main difference between desiccant and silica gel.

Reference:

1. “Overview of Silica Gel.” Science Direct.
2. “Overview of Desiccant.” Science Direct.

Image Courtesy:

1. “Desiccant Canister” By Pharmadesiccants – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “White silica gel” (Public Domain) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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