Silica Gel Molecular Sieve

No Nitrogen Required! DesiTrays™ convert a Terra Desiccator into a low-RH Drying Cabinet

DesiTray™ Renewable Drying System

• Ideal for low-humidity storage or drying in facilities with no nitrogen source
• Versatile trays fit inside most standard Terra desiccator chambers
• Maintains humidity level down to 5% RH
• Renewable silica gel or molecular sieve drying medium is easy to regenerate for repeated use
• Tray snaps open for replacement of desiccant
• Large volume of desiccant (2 lbs.) extends service before regeneration is required

These DesiTrays™ create a convenient dry storage environment inside any Terra desiccator.

Their low-profile design allows insertion below adjustable shelving, consuming virtually no storage space. The noncontaminating 304 stainless steel housing contains your choice of silica gel or molecular sieve (see comparison sidebar below). To regenerate the DesiTray™, simply heat it inside any appropriate lab oven until the indicating desiccant turns blue (see temperature and oven recommendations below)

	Cat. #	$/Each
304 Stainless Steel DesiTray™ Order one/chamber. Each holds two pounds of desiccant (order below)	1900-01	Login
Silica Gel (20-lb. can)	1900-02
Molecular Sieve (20-lb. can)	1900-03	Login

Molecular Sieve or Silica Gel?

Silica Gel is a hard, translucent amorphous silicate made from naturally occurring sodium silicate and sulfuric acid. It offers an extremely high capacity for moisture adsorption--nearly 40% of its own weight at 100%RH--but loses its ability to adsorb moisture at levels below 40% RH. It also loses its adsorption capacity at temperatures above 77°F, making it a less efficient desiccant at above-ambient temperatures but also easier to desorb (regenerate).

The beads of dry silica gel change color from blue to pink when about 6% water (by weight) has been adsorbed. If used silica beads are warmed to temperatures over 212°F (but not exceeding 350°C) they regain their original blue color and are ready for reuse.

Molecular Sieves are synthetically produced zeolites that feature perfectly uniform pore sizes. They come in several pore sizes; Terra offers Type 4A, with 4 angstrom pores that are effective for regenerable use with water.

Like silica gel, they remove moisture through adsorption and capillary action, but they do so more efficiently, especially at low humidity and high temperature levels. They are preferable to silica gel when the RH falls below 40% or the temperature climbs above 77°F. Because of this affinity for water, a molecular sieve requires somewhat higher temperature for regeneration, typically between 250° and 300°F.