Abstract: Provided are systems for storing and generating hydrogen comprising a solution that comprises a reaction product of (a) a photosensitized oxidation product of methanol; and (b) a reduction product of oxygen and a photoreduced photosensitizer, wherein the system generates hydrogen gas when a basic material is added to the solution. Preferably, the photosensitizer is an anthraquinone. The photosensitizer may be dissolved in the liquid solution or may be in a solid phase in the solution. Preferably, the solid phase is a porous membrane, most preferably an inorganic oxide xerogel membrane, and the photosensitizer is complexed to an inorganic oxide xerogel material. Also provided are methods for storing hydrogen by providing methanol, an oxidative photosensitizer, oxygen, and light that is absorbed by the photosensitizer. Hydrogen gas is generated by the addition of a basic material.

Abstract: The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110° C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

Abstract: Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Preferably, the inorganic oxide comprises an hydrated aluminum oxide of the formula Al2O3.xH2O, wherein x is less than 1.0, and wherein the hydrated aluminum oxide comprises organic substituents, preferably comprising a reaction product of a multifunctional monomer and/or organic carbonate with an aluminum oxide, such as pseudo-boehmite and an aluminum oxide. Also provided are electrochemical cells comprising such separators.

Abstract: Provided are methods of preparing a separator for an electrochemical cell comprising the steps of (a) coating onto a substrate a liquid mixture comprising an inorganic oxide, an organic polymer, a divinyl ether of an ethylene glycol, and/or an organic carbonate; (b) drying the coating; and (c) delaminating the coating from the substrate to form the separator comprising an inorganic oxide and the organic polymer, wherein the inorganic oxide of step (c) comprises a reaction product of the divinyl ether and/or the organic carbonate with the inorganic oxide of step (a). Preferably, the inorganic oxide of step (c) comprises a hydrated aluminum oxide of the formula Al2O3.H2O, wherein x is less than 1.0, and wherein the hydrated aluminum oxide comprises a reaction product of the divinyl ether and/or organic carbonate with the inorganic oxide of step (a), such as pseudo-boehmite.

Abstract: The present invention pertains to organic reflective layers comprising an organic radical cation compound, wherein the layer reflects in the infrared region. Preferably, the organic radical cation compound is a salt of an aminium radical cation. Also provided are marking systems comprising such reflective layers and methods of marking an article utilizing such reflective layers.

Abstract: Provided is an electro-optic reflective modulator comprising a reflective active material, preferably comprising a reflective organic free radical compound, that reflects a wavelength in a highly reflective state and is reversibly switched to a transparent and low reflectivity state at the wavelength by the application of an electric current. Preferably, the electro-reflective optical modulator is solid state with no moving parts such that the active material does not move when reversibly switched between the high and low reflective states. Also provided are methods of modulating an optical signal utilizing such electro-optic reflective modulators.

Abstract: Provided are methods of preparing an article, such as an electrochemical cell, in which a microporous layer is coated on a temporary carrier substrate and a substrate, such as an electrode, is then laminated or contacted to the microporous layer, after or prior to removing the temporary carrier substrate from the microporous layer. The microporous layer comprises one or more microporous xerogel layers comprising a xerogel material, such as a zirconium oxide xerogel material. Also provided are articles, such as electrochemical cells and separators, prepared by such methods.

Abstract: Provided is an electro-optic modulator comprising an organic free radical compound, preferably comprising a reflective organic free radical compound, as an active modulating material. The modulator is reversibly switched between two states of high and low transmission at a wavelength by the application of an electric current. Preferably, the optical modulator is solid state with no moving parts such that the active modulating material does not move when reversibly switched between the two states. Also provided are methods of modulating an optical signal utilizing such electro-optic modulators.

Abstract: Provided is an electro-optic reflective modulator comprising a reflective active material, preferably comprising a reflective organic free radical compound, that reflects a wavelength in a highly reflective state and is reversibly switched to a transparent and low reflectivity state at the wavelength by the application of an electric current. Preferably, the electro-reflective optical modulator is solid state with no moving parts such that the active material does not move when reversibly switched between the high and low reflective states. Also provided are methods of modulating an optical signal utilizing such electro-optic reflective modulators.

Abstract: The present invention pertains to organic reflective layers comprising an organic radical cation compound, wherein the layer reflects in the infrared region. Preferably, the organic radical cation compound is a salt of an aminium radical cation. Also provided are marking systems comprising such reflective layers and methods of marking an article utilizing such reflective layers.