Silica gel was patented by chemistry professor Walter A. Patrick at Johns Hopkins University, Baltimore, Maryland in 1919. Prior to that, it was used in World War I for the absorption of vapors and gases in gas mask canisters. The substance was in existence as early as the 1640s as a scientific curiosity.
In World War II, silica gel was indispensable in the war effort for keeping penicillin dry, protecting military equipment from moisture damage, as a fluid cracking catalyst for the production of high octane gasoline, and as a catalyst support for the manufacture of butadiene from ethanol, feedstock for the synthetic rubber program.