A composite structure including a metal form. The composite structure further includes an aerogel matrix formed of an aerogel, with the aerogel matrix being nanoporous and including a plurality of aerogel pores. A polymer occupies at least a portion of the aerogel pores of the aerogel matrix. The polymer is a thermoplastic. The thermoplastic is nanoporous and includes a plurality of thermoplastic pores. The thermoplastic pores are less than 10 nanometers in size. The polymer is impregnated within the aerogel pores of the aerogel matrix. The aerogel comprises at least 20% by weight of the composite structure. The aerogel pores are less than 10 nanometers in size. The composite structure further contains filler material. The filler material may be graphene. The composite structure further contains reinforcing agents.

A composite structure including a metal form. The composite structure further includes an aerogel matrix formed of an aerogel, with the aerogel matrix being nanoporous and including a plurality of aerogel pores. A polymer occupies at least a portion of the aerogel pores of the aerogel matrix. The polymer is a thermoplastic. The thermoplastic is nanoporous and includes a plurality of thermoplastic pores. The thermoplastic pores are less than 10 nanometers in size. The polymer is impregnated within the aerogel pores of the aerogel matrix. The aerogel comprises at least 20% by weight of the composite structure. The aerogel pores are less than 10 nanometers in size. The composite structure further contains filler material. The filler material may be graphene. The composite structure further contains reinforcing agents.

A method of freeze-drying comprising rapidly freezing either liquid or supercritical carbon dioxide in and around a material having pores at a rate of at least 0.2° C./min to limit the size of crystals formed from the carbon dioxide so as to avoid the formation of gas bubbles and damage to the pores and exposure of the material to gas-liquid interfaces. During freezing a solid layer primarily of solid carbon dioxide is formed on and surrounding the material by transferring heat with a cryogenic liquid circulating about the material. This solid layer protects the material from gas-liquid interfaces and surface tension before decreasing pressure about the material by venting carbon dioxide.

A method of freeze-drying comprising rapidly freezing either liquid or supercritical carbon dioxide in and around a material having pores at a rate of at least 0.2° C./min to limit the size of crystals formed from the carbon dioxide so as to avoid the formation of gas bubbles and damage to the pores and exposure of the material to gas-liquid interfaces. During freezing a solid layer primarily of solid carbon dioxide is formed on and surrounding the material by transferring heat with a cryogenic liquid circulating about the material. This solid layer protects the material from gas-liquid interfaces and surface tension before decreasing pressure about the material by venting carbon dioxide.

A classifying and purifying apparatus of a solid blowing agent includes a classifier which classifies a supplied solid blowing agent into first microspheres and second microspheres, a storage connected to the classifier, in which the classified first microspheres flow in to be stored and emitted, and a filter arranged on the moving route of the solid blowing agent or the first microspheres which separates metallic substance from the object of filtering comprising the solid blowing agent or the first microspheres.

A classifying and purifying apparatus of a solid blowing agent includes a classifier which classifies a supplied solid blowing agent into first microspheres and second microspheres, a storage connected to the classifier, in which the classified first microspheres flow in to be stored and emitted, and a filter arranged on the moving route of the solid blowing agent or the first microspheres which separates metallic substance from the object of filtering comprising the solid blowing agent or the first microspheres.

A method of producing a metal form containing dispersed aerogel particles impregnated with polymers comprising a method of impregnating an aerogel with polymers, placing the aerogel impregnated with polymers within a dissolved polymer, cooling the dissolved polymer to create a polymer form with dispersed aerogel particles impregnated with polymers, adding molten metal to the polymer form, vaporizing the polymer form, replacing the polymer form with molten metal, and cooling the molten metal to yield a metal form containing dispersed aerogel particles impregnated with polymers. Dispersing the aerogel particles impregnated with polymers within the polymer form prior to adding molten metal allows the aerogel particles to be fully dispersed throughout the metal form.

A method of producing a metal form containing dispersed aerogel particles impregnated with polymers comprising a method of impregnating an aerogel with polymers, placing the aerogel impregnated with polymers within a dissolved polymer, cooling the dissolved polymer to create a polymer form with dispersed aerogel particles impregnated with polymers, adding molten metal to the polymer form, vaporizing the polymer form, replacing the polymer form with molten metal, and cooling the molten metal to yield a metal form containing dispersed aerogel particles impregnated with polymers. Dispersing the aerogel particles impregnated with polymers within the polymer form prior to adding molten metal allows the aerogel particles to be fully dispersed throughout the metal form.

Antioxidant-containing expandable resin particles including composite resin particles containing 100 to 400 parts by mass of polystyrene-based resin relative to 100 parts by mass of polypropylene-based resin, and a blowing agent and an antioxidant contained in the composite resin particles, wherein the polypropylene-based resin is abundantly present on the surface of the composite resin particles and poorly present at the center of the particles, and the composite resin particles contain 150 to 1500 ppm of antioxidant.

Low-density thermoplastic expandable microspheres are disclosed. Various low-density structures, in particular, sandwich panels, based on foam prepared from the low-density microspheres, are also disclosed. Process of preparing low-density polymeric microspheres, per se, and the corresponding low-density structures, based on the microsphere foam, are also disclosed.