The foamed sheet of the present invention is a foamed sheet obtained by crosslinking and foaming a polyvinylidene fluoride-based resin composition comprising a polyvinylidene fluoride-based resin, wherein the polyvinylidene fluoride-based resin comprises a vinylidene fluoride-hexafluoropropylene copolymer, a density of the foamed sheet is not more than 180 kg/cm.sup.3, and an average cell diameter of the foamed sheet is not less than 100 μm and not more than 500 μm. According to the present invention, a crosslinked polyvinylidene fluoride-based resin foamed sheet having both good flame retardance and good flexibility and a process for producing the foamed sheet are provided.

A polymeric sheet, at least partially cross-linked and/or foamed, having a substantially open cell foam structure is described. A continuous method of manufacturing of an at least partially cross-linked, open cell foamed polymeric sheet is also described.

An example device includes a nanovoided polymer element, a first electrode, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. In some examples, the nanovoided polymer element may include anisotropic voids. In some examples, anisotropic voids may be elongated along one or more directions. In some examples, the anisotropic voids are configured so that a polymer wall thickness between neighboring voids is generally uniform. Example devices may include a spatially addressable electroactive device, such as an actuator or a sensor, and/or may include an optical element. A nanovoided polymer layer may include one or more polymer components, such as an electroactive polymer.

A method for modifying a cellular polymer foam with apparent porosity, which includes providing a cellular polymer foam with apparent porosity, placing the cellular polymer foam in contact with at least one compound in order to obtain a cellular polymer foam including on the surface thereof an intermediate phase formed from the compound having at least one catechol unit. The foam may be used as a catalyst substrate.

A composition for forming a foamed silicone elastomer is disclosed. The composition comprises: A) an organopolysiloxane having at least two silicon-bonded ethylenically unsaturated groups per molecule; B) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; C) a hydrosilylation catalyst; D) a chemical blowing agent; and E) a physical blowing agent. The hydrosilylation catalyst C) is present in a catalytically effective amount. The chemical blowing agent D) has at least one hydroxyl (OH) group, and is present in an amount to provide a OH content >0 and <500 parts per million (ppm). The physical blowing agent E) undergoes a phase change from a liquid to a gaseous state during exposure to atmospheric pressure and a temperature ≥0° C. The blowing agents D) and E) are different from one another. A foamed silicone elastomer, and methods of forming the composition and foamed silicone elastomer are also disclosed.

The present invention includes a hydrogel and a method of making a porous hydrogel by preparing an aqueous mixture of an uncrosslinked polymer and a crystallizable molecule; casting the mixture into a vessel; allowing the cast mixture to dry to form an amorphous hydrogel film; seeding the cast mixture with a seed crystal of the crystallizable molecule; growing the crystallizable molecule into a crystal structure within the uncrosslinked polymer; crosslinking the polymer around the crystal structure under conditions in which the crystal structure within the crosslinked polymer is maintained; and dissolving the crystals within the crosslinked polymer to form the porous hydrogel.

Embodiments of the disclosure are generally directed to systems and methods for switchable electroactive devices for head-mounted displays (HMDs). In particular, a method may include (1) applying an electric field to an electroactive element of an electroactive device via electrodes of the electroactive device that are electrically coupled to the electroactive element to compress the electroactive element, which comprises a polymer material defining nanovoids, such that an average size of the nanovoids is decreased and a density of the nanovoids is increased in the electroactive element, wherein the electroactive device is positioned at a distance from a user's eye, and (2) emitting image light from an emissive device positioned such that at least a portion of the image light is incident on a surface of the electroactive device facing the user's eye.

The present invention provides porous materials for use in solid phase extractions and chromatography. In particular, the materials exhibit superior properties in the SPE analysis of biological materials. In certain aspects, the porous materials comprise a copolymer of a least one hydrophobic monomer and at least one hydrophilic monomer, wherein more than 10% of the BJH surface area of the porous material is contributed by pores that have a diameter greater than or equal to 200 Å, wherein said material has a median pore diameter of about 100 Å to about 1000 Å, or both. In some embodiments, the at least one hydrophilic monomer has a log P value of less than 0.5. In some embodiments, the at least one hydrophilic monomer is selected from 4-acryloymorphine, N-(3-methoxypropyl)acrylamide, N,N′-methylenebis(acrylamide), acrylonitrile, ethylene glycol dimethacrylate, methyl acrylate, 4-acetoxystyrene, 4-vinyl pyridine, or a boronic-acid-containing monomer, among others.

An example device includes a nanovoided polymer element, which may be located at least in part between the electrodes. In some examples, the nanovoided polymer element may include anisotropic voids, including a gas, and separated from each other by polymer walls. The device may be an electroactive device, such as an actuator having a response time for a transition between actuation states. The gas may have a characteristic diffusion time (e.g., to diffuse half the mean wall thickness through the polymer walls) that is less than the response time. The nanovoids may be sufficiently small (e.g., below 1 micron in diameter or an analogous dimension), and/or the polymer walls may be sufficiently thin, such that the gas interchange between gas in the voids and gas absorbed by the polymer walls may occur faster than the response time, and in some examples, effectively instantaneously.

Described herein are physically crosslinked, closed cell continuous multilayer foam structures that includes a foam layer comprising polypropylene, polyethylene, or a combination of polypropylene and polyethylene and a polyamide cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer and at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.