A method of making a porous structure configured for use in a particulate filter includes bonding a plurality of glass bubbles to one another, and breaching the plurality of glass bubbles. Voids within individual breached glass bubbles open into one another to form cavities that extend through the porous structure.

A high-strength geopolymer hollow microsphere, a preparation method thereof and a phase change energy storage microsphere are provided, including: dissolving sodium hydroxide, sodium silicate and spheroidizing aid in water to form a solution A, and adding active powder to the solution A, stirring and uniformly mixing to form a slurry B, adding the slurry B to an oil phase, stirring and dispersing into balls, filtering to obtain geopolymer microspheres I, washing the geopolymer microspheres I, and then carrying out a high-temperature calcination to obtain the high-strength geopolymer hollow microspheres II; using the high-strength geopolymer hollow microsphere as a carrier, absorbing a phase change material into the carrier, and mixing a microsphere carrying the phase change material with an epoxy resin, adding a powder dispersant and stirring to disperse the microsphere, after the epoxy resin is solidified, screening the superfluous powder dispersant to obtain the phase energy storage microsphere.

Microspheres comprising a plurality of hollow microspheres, each of the plurality of hollow microspheres comprising a plurality of glass walls, and a plurality of hollow spaces, wherein the plurality of glass walls enclosing at least one of the plurality of hollow spaces, wherein the plurality of glass walls comprising a second glass, wherein the second glass comprising a processed first glass melt, wherein the processed first glass melt comprising a melt of a batch and a plurality of redox active group components capable of providing at least one of a plurality of redox reactions and a plurality of events in the second glass.

Hollow microbeads of glass are produced during a number of operating phases in which an upwardly directed hot gas flow is produced in a firing chamber by firing a vertical furnace. The firing chamber is continuously charged with microparticles of a starting glass material and the microparticles are expanded in the hot gas flow into the hollow microbeads. Expanded hollow microbeads are discharged out of the firing chamber with the gas flow through a gas outlet at the upper end of the vertical furnace. Between successive operating phases there is respectively provided a charging break, during which the charging of the firing chamber with the microparticles is suspended. In these charging breaks, the microparticles remaining in the firing chamber are respectively removed from the firing chamber.

Methods and apparatus are disclosed for producing seeds that are transformed into hollow spheres. A seed includes a core and a coating. Upon heating, the coating becomes viscous and expands responsive to an internal gas pressure created by the core. Example applications for the seeds and/or cores are disclosed, including bricks and other construction materials having the hollow spheres incorporated therein.

Methods for producing a hollow spheres, optionally with a vacuum inside, are disclosed. An example method includes providing a seed with a core and a coating. The seed is heated to a temperature sufficient to transform the coating into a continuous shell having an interior and an exterior. The shell isolates the core from the exterior of the shell. The temperature is also sufficient to cause a reaction with the materials of the core, and the reaction converts the core to a gas within said shell. Controlling the rate of heating and the pressure surrounding the shell allows the shell to expand responsive to gas pressure within the shell. Cooling the shell causes the gases within the shell to revert to a solid form, thereby creating a vacuum within the shell. Products incorporating the hollow spheres are also disclosed.

The present invention is directed to hollow aluminosilicate glass particles and a process for the production thereof. Further, the present invention is directed to an article comprising said hollow aluminosilicate glass particles as well as the use of said particles as a filler for high temperature products, molten metal, injection moulded synthetic materials, flame-retardant insulating foams, cement slurries, mortars, concretes and oil field applications.

A method for producing hollow glass microspheres includes preparing an aqueous suspension of starting materials including finely ground glass and waterglass. Combustible particles are produced from the suspension and are mixed with an AlO(OH)-containing pulverulent release agent. The mixture of combustible particles and release agent is introduced into a combustion chamber of a furnace where it is expanded at a combustion temperature which exceeds the softening temperature of the finely ground glass, to form the hollow microspheres. Hollow glass microspheres produced according to the method are also provided.

Transparent and insulating materials having evacuated capsules are provided. According to an aspect of the invention, a method includes forming evacuated capsules within a solution, and dispersing and suspending the evacuated capsules within the solution such that a packing density of the evacuated capsules within the solution is greater than 30%, and a visible light transmission of the solution including the evacuated capsules is greater than 75%. According to another aspect of the invention, a layer includes a plurality of evacuated capsules distributed within a dried sol-gel. A thermal conductivity of the layer is between 0.02 W/m-K and 0.001 W/m-K, and the layer has a visible light transmission of greater than 30%.

A hollow spherical glass particle, comprising aluminum oxide Al.sub.2O.sub.3, silicon dioxide SiO.sub.2 and at least one metal oxide, wherein the metal oxide is selected from the group consisting of alkali metal oxides and alkaline earth metal oxides, wherein the ratio of aluminum atoms to alkali metal atoms is about 1:1 and the ratio of aluminum atoms to earth alkali atoms is about 2:1, with the proviso that the hollow spherical glass particle is free of boron.