Silica Gel Uses

Silica gel is a vitreous (or glass-like), granular, and highly porous form of silica made synthetically from sodium silicate. Even though it is called a "gel," silica gel is a solid. It is made by taking sodium silicate, a naturally occurring mineral, and purifying and processing it into either a granular or beaded form. It is a desiccant, meaning that it absorbs moisture and causes dryness of nearby substances in a well-sealed container.

  1. Desiccant beads

    • Silica gel is most commonly found as beads packed in a vapor-permeable plastic container and used as a desiccant that controls the humidity of objects around it. It is also used to help avoid some goods from spoiling and degrading due to exposure to moisture. Most people become familiar with this kind of silica gel through the small packages in electronics and vitamins. These packages are clearly labeled "Do not eat" because silica gel is highly poisonous.

    Chromatography

    • Silica gel is used in the chemistry process called "chromatography," which refers to a group of techniques used in the laboratory that separates chemical mixtures. This process involves passing a mixture from a mobile phase through a stationary phase, which separates the molecules in the mixture for later use and acts as purification of the mixture. Silica gel is used in the stationary phase of chromatography because it does not biodegrade in water and soil.

    Kitty Litter

    • Silica gel is used as cat litter, either by itself or in combination with more traditional materials like clays and soil. It was developed in cat litter because it prevents urine odors, since it absorbs uric acid, and it is trackless. Materials like sand or sawdust were used historically, but it was hard to clean. So cat owners were happy when silica gel was added to cat litter because it causes clumping of the soiled material. It also prevents the problem of cats tracking sand, dust or sawdust through the house.