Self-indicating porous metal hydroxides incorporating metal reactants for toxic chemical removal and sensing

#The invention relates to compositions, methods and devices that may be used to monitor the presence or absence of a hazardous chemical in the environment. More specifically, porous sorbents, specifically metal oxides and metal hydroxides, are provided for the removal of toxic chemicals and the self-indicating color/spectral changes associated with said toxic chemical removal. The methods and devices provided by the invention are applicable to several fields including catalysis, decontamination, sensing, separations, gas storage, and others. The provided compositions may be used in respirators and/or collective protection filters for use as end-of-service life indicators (ESLI) and/or residual life indicators (RLI). Exemplary devices employing the invention alert a user to when it is time to change-out the filter.

#Air purification, including individual and collective protection filtration, is of major concern to the military, first responders, and industrial workers. Filters typically containing activated, impregnated carbons are employed to filter toxic chemicals, and have limited lifetimes after exposure. Furthermore, due to interaction with environmental contaminants, such as low level concentrations of SOx, NOx, hydrocarbon vapors, etc., the capacity of filters can degrade even before a toxic chemical event.

#In individual protection having an end-of-service-life indicator (ESLI) that tells the user when the filter has run out of protective capability is a major development thrust, and a need for the community. Here, an ESLI should interact/react with toxic chemicals such that a response (ideally visible, but not necessarily) occurs. There are ESLI technologies currently being fielded; however, there are severe shortcomings to these, such as poor sensing of reactive gases or insufficient reactivity.

#The patent or patent application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

#FIG. 1 illustrates the colorimetric changes of various sorbents following exposure to an array of toxic chemicals;

#FIG. 2 illustrates FTIR analyses of colorimetric changes of the sorbent 7% KMnO4/Zr(OH)4 following exposure to an array of toxic chemicals;

#The following description of particular embodiment(s) is merely exemplary in nature and is in no way intended to limit the scope of the invention, its application, or uses, which may, of course, vary. The invention is described with relation to the non-limiting definitions and terminology included herein. These definitions and terminology are not designed to function as a limitation on the scope or practice of the invention but are presented for illustrative and descriptive purposes only. While the compositions are described as using specific materials in a particular order, it is appreciated that the described materials or order may be interchangeable such that the description of the invention includes multiple parts or steps arranged in many ways as is readily appreciated by one of skill in the art.

#The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms, including “at least one,” unless the content clearly indicates otherwise. “Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. The term “or a combination thereof” means a combination including at least one of the foregoing elements.

#Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.