Provided herein are methods for fabricating a porous polymer material, methods for revealing hidden anti-counterfeiting patterns, chromogenic sensors having hidden anti-counterfeiting patterns, and the like. Chromogenic sensors including porous polymer materials are provided. The chromogenic sensors can reveal hidden patterns such as anti-counterfeiting patterns and the pattern can be re-hidden.

Provided herein are methods for fabricating a porous polymer material, methods for revealing hidden anti-counterfeiting patterns, chromogenic sensors having hidden anti-counterfeiting patterns, and the like. Chromogenic sensors including porous polymer materials are provided. The chromogenic sensors can reveal hidden patterns such as anti-counterfeiting patterns and the pattern can be re-hidden.

Provided herein are materials, methods of making materials, and methods of use, wherein the materials have switchable adhesive properties. Materials of the present disclosure can reversibly change coloration in conjunction with the changing adhesive state. The films, made from a porous polymer material, can be reversibly changed from a smooth state to a rough state, allowing for reversible and tunable gripping and/or adhesive properties.

Provided herein are materials, methods of making materials, and methods of use, wherein the materials have switchable adhesive properties. Materials of the present disclosure can reversibly change coloration in conjunction with the changing adhesive state. The films, made from a porous polymer material, can be reversibly changed from a smooth state to a rough state, allowing for reversible and tunable gripping and/or adhesive properties.

A composition that includes porous polyurethane particles is provided. The porous particles are formed by curing an isocyanate component with water in the presence of a polyester filler and a hydrocarbon phase. A method for the preparation of porous polyurethane particles is also provided. The method includes providing a dispersed medium that contains a hydrocarbon phase, water, and a polyester filler. Then, an isocyanate component that is immiscible with the hydrocarbon phase may be added to the dispersed medium to form polyurethane prepolymer droplets, that may be cured by the water in the medium. An additional method for porous polymer particle preparation that includes providing a dispersed medium comprising a hydrocarbon phase, an isocyanate component that is immiscible in the hydrocarbon phase, and a polyester filler is provided. The dispersed medium may be agitated to form polyurethane prepolymer droplets, that may be cured by adding water.

A composition that includes porous polyurethane particles is provided. The porous particles are formed by curing an isocyanate component with water in the presence of a polyester filler and a hydrocarbon phase. A method for the preparation of porous polyurethane particles is also provided. The method includes providing a dispersed medium that contains a hydrocarbon phase, water, and a polyester filler. Then, an isocyanate component that is immiscible with the hydrocarbon phase may be added to the dispersed medium to form polyurethane prepolymer droplets, that may be cured by the water in the medium. An additional method for porous polymer particle preparation that includes providing a dispersed medium comprising a hydrocarbon phase, an isocyanate component that is immiscible in the hydrocarbon phase, and a polyester filler is provided. The dispersed medium may be agitated to form polyurethane prepolymer droplets, that may be cured by adding water.

The present disclosure provides for porous polymer materials that include an ordered array of voids separated by a polymer framework. The porous polymer material can have a recovery state where the voids are in an uncollapsed state and iridescent color, and a deformed state having voids in a collapsed state that is non-iridescent or substantially transparent. The materials can have regions of both states simultaneously. Also described are methods for fabricating a polymer material as above, as well as chromogenic sensors including the polymer material. The sensors can have hidden anti-counterfeiting patterns, hydrophobic/oleophobic properties, and chromogenic transformation can be triggered by various stimuli such as solid target compounds, light energy, and more.

The present disclosure provides for porous polymer materials that include an ordered array of voids separated by a polymer framework. The porous polymer material can have a recovery state where the voids are in an uncollapsed state and iridescent color, and a deformed state having voids in a collapsed state that is non-iridescent or substantially transparent. The materials can have regions of both states simultaneously. Also described are methods for fabricating a polymer material as above, as well as chromogenic sensors including the polymer material. The sensors can have hidden anti-counterfeiting patterns, hydrophobic/oleophobic properties, and chromogenic transformation can be triggered by various stimuli such as solid target compounds, light energy, and more.