3m Innovative Properties Company

J Christopher Thomas

Neal A Rakow

Duane Douglas Fansler

John E Trend

Maria Lenni Zelinsky

Kevin A Frankel

Denise L Goddard

Melissa A Checky

Maria L Zelinsky

Layered filtered cartridge systems with an End of Service Life Indicating system include a filter cartridge that includes filter media. The filter media includes a multi-layer construction, of a first sorbent layer, a second sorbent layer, and a sensing element adjacent to the first and second sorbent layers such that an indicating element of the sensing element is located at the interface between the first and second sorbent layers. The first sorbent layer has a higher adsorption capacity and/or higher adsorption rate than the second sorbent layer. The sensing element indicates the passage of an adsorption wavefront through the filter cartridge.

End of service life indicating systems for layered filter cartridges

Chemical indicators for acidic or basic gases include an inert, porous substrate, an indicator dye or mixture of dyes contained within at least some of the pores of the inert, porous substrate, and an inert adhesive layer attached to the inert, porous substrate. The porous substrate may be a microporous substrate.

Porous chemical indicator for gaseous media

Multi-layered optical sensor films are disclosed. The sensor films include a first reflective layer, a detection layer over the reflective layer, and optionally a second reflective layer over the detection layer. The detection layer contains a hydrophobic, amorphous, substantially microporous, analyte-sensitive organosilicate composition. The analyte-sensitive organosilicate composition provides an optical change in the film upon analyte exposure.

Organic chemical sensor with microporous organosilicate material

Growing community of inventors

Saint Paul, MN, United States of America

J Christopher Thomas