Lab Desiccants and Drying Agents
Hygroscopic substances and drying agents for use in laboratory settings; drying agents are commonly used to keep other substances and samples dry, or to prevent moisture from forming on/in containers. Products include drying tubes, kits, etc.
Desiccants are typically chemicals or compounds that are hydroscopic (readily absorb moisture). Common desiccants include clays, silica gels, and calcium sulfate.
In the lab, desiccants are commonly used in desiccators and desiccator cabinets, with in-line air and gas drying columns, in absorption bulbs, U-tubes, glove boxes, sealed chambers, and wherever a dry environment is required. They are also used during transport, for storage, and maintaining materials and products ─ everything from clothing to electronics.
The moisture may come from a variety of sources:
- Water vapor in the air
- Moisture in packaging materials
- Moisture from permeation or leakage
Some desiccants contain an indicator or additive that produces a color change with moisture absorption. The indicator allows the user to see when the desiccant has absorbed its maximum amount of moisture and needs to be replaced or regenerated.
Some desiccants can be reused many times simply by heating them in an oven to allow moisture to evaporate. For indicating desiccants, one can also easily tell when the desiccant is again ready to use by the change back to the original color.
Desiccants may be available in a range of mesh or particle sizes. The Tyler Equivalent is a common type of mesh sizing and indicates the number of openings per linear inch of mesh. Common desiccant mesh sizes are 4, 8, and 10 to 12. Size 4 is typically used in gas phase applications; they are larger and less likely to break. Size 8 is smaller and can be more tightly packed.
Thomas Scientific Ascarite II CO2 Absorbent, 1310-73-2, MFCD00003548, 8-20 MESH 500 G
Ascarite II is a specially formulated mixture of Sodium Hydroxide on an inert silica carrier, providing a surface area especially suited for the rapid, high performance and total absorption of CO2 on contact. Ascarite II CO2 Absorbent is an aggressive, high performance quantitative absorbent of carbon dioxide. Utilized by the US military, Ascarite II can be used in environmental labs, chromatographic applications, and chemical and steel manufacturing plants.
Sorbent Technologies Inc Activated Alumina Spheres, 7x14 Mesh, 2.0mm, 1kg
The activated alumina spheres are very porous, have a high surface area, and do not change form. They will not soften or disintegrate when immersed in liquids. When used to adsorb water, they act as an efficient desiccant. Molecules with the highest polarity are preferentially adsorbed. In the absence of irreversible fowling, they may be regenerated by heating to a temperature between 177-316C. Applications: Drying and purification of organic liquids and gases; adsorption of heavy metals such as fluorides, phosphates, arsenic acids, and humic acids; purification of processing liquids, industrial water, and waste water by removing highly polar compounds such as: TBC, alcohols, ethers, etc.; removal of acids formed from the degradation of transformer oils, lubricating oils, and refrigerants; removal of residual halides and water during the manufacture of chlorinated and/or fluorinated hydrocarbons, yielding a non-corrosive product.
Electron Microscopy Sciences Silica Gel Bulk Desiccant, 2 Lbs
Changes color when it reaches max absorption capacity.
eMolecules Oakwood Chemicals Silica gel 40-60Angstoms 5kg 480169645 LC4025 0 000 112926-00-8 MFCD00011232 60 083 O2Si
Oakwood Chemicals Silica gel 40-60Angstoms 5kg 480169645 LC4025 0 000 112926-00-8 MFCD00011232 60 083 O2Si