The invention relates to a method and a device for producing hollow microglass beads (3.4) from molten glass (3), wherein the hollow microglass beads (3.4) are manufactured in a diameter range from 0.01 mm to 0.1 mm in a continuously operating process while avoiding glass filament formation. Molten glass strands (3.1) exiting a melting device (1) are atomized by means of hot gas (14) to form glass particles (3.2). Subsequently, during passage through a rounding/expansion duct (6), the glass particles (3.2) are rounded to form solid microglass beads (3.3) and expanded to form hollow microglass beads (3.4). The hollow microglass beads (3.4) can advantageously be used as a filler for lightweight building materials or as a constituent part of coatings, paints and plasters/renders.

Hollow glass microspheres are produced. An aqueous suspension is prepared of starting materials of finely ground glass and waterglass. Firing material particles are produced from the suspension and are mixed with a pulverulent release agent. The mixture of firing material particles and release agent is introduced into a firing chamber of a furnace where it is expanded at a firing temperature which exceeds the softening temperature of the finely ground glass, to form the hollow microspheres. The release agent is Al(OH).sub.3 and dehydroxylated kaolin.

A process and a plant produce hollow microspheres made of glass. According to the process an aqueous suspension is prepared from starting materials containing glass powder and water glass, feedstock particles having a diameter between 5 ?m and 300 ?m, in particular between 5 ?m and 100 ?m, being produced from the suspension. The feedstock particles are mixed with a pulverulent release agent made of aluminum hydroxide in an intensive mixer. The mixture of feedstock particles and release agent is subsequently introduced into a firing chamber of a furnace. The feedstock particles expand in the firing chamber, at a firing temperature which exceeds the softening temperature of the glass powder, to form the hollow microspheres.

Apparatuses and methods of forming hollow spheres are provided. Hollow sphere forming apparatus incorporate a bubble forming nozzle assembly in which outlets for gas and liquid materials are disposed substantially coaxially. The relative positions of the gas and liquid outlets are adjustable in at least one dimension (e.g., axially, radially or angularly relative to each other), such that a more uniform annular exit region for the gas and liquid outlets may be configured, such that more symmetric bubbles may be formed thus reducing the rejection rate in solidified bubbles due to asymmetry or decentering of entrapped gas.

Hollow glass microspheres (HGMS) with a controlled nanotopographical surface structure (NSHGMS) demonstrate improved isolation and recovery of cells and other biological particles such as bacteria from biological fluid. Such functionalized HGMS are formed by exposing a plurality of hollow glass microspheres to a layer by layer deposition cycle of charged polymeric nanofilms to form a plurality of coated hollow glass microspheres and functionally binding a plurality of biotinylated antibodies to the plurality of coated hollow glass microspheres. Application of these HGMS in related biological particle isolation methods does not require specialized lab equipment or an external power source, and thus, can be used for separation of targeted cells from blood or other fluid in a resource-limited environment.

Apparatuses and methods of forming hollow spheres are provided. Hollow sphere forming apparatus incorporate a bubble forming nozzle assembly in which outlets for gas and liquid materials are disposed substantially coaxially. The relative positions of the gas and liquid outlets are adjustable in at least one dimension (e.g., axially, radially or angularly relative to each other), such that a more uniform annular exit region for the gas and liquid outlets may be configured, such that more symmetric bubbles may be formed thus reducing the rejection rate in solidified bubbles due to asymmetry or decentering of entrapped gas.

Process for the preparation of hollow spherical glass particles comprising at least SiO.sub.2, Al.sub.2O.sub.3, and an alkali metal oxide, wherein the process comprises the preparation of precursor particles comprising at least SiO.sub.2, Al.sub.2O.sub.3, and an alkali metal oxide by mixing the starting materials, slurrying the starting materials with water followed by spry-drying and heat-treating the obtained precursor-particles at a temperature from 1000 C. to 1800 C., preferably from 1300 C. to 1600 C. by contacting the precursor particles with at least one naked flame.