The present disclosure concerns expandable silica particles having a coating comprising talc powder and kaolin powder provided on the outer surface of the expandable silica particle and expandable and expanded silica particles comprising silica fume and/or ultrafine quartz silica sand beneath the surface of the particles. Methods for producing expandable and expanded silica particles are disclosed, including a method using a vibration plate and a furnace having a vibration plate for carrying out that method. The expanded silica particles have high compressive strength, substantially uniform cell size and distribution, low water absorption, and low porosity on the outer surface. They are useful as a filler in matrix materials, like concrete or epoxy, as insulation material with various binder materials, and as water filtration medium.

A plurality of glass bubbles having, in combination, a D50 size of no greater than 13 micrometers, an average true density of no greater than 0.42 grams per cubic centimeter, and a 90% crush strength of at least 55 megapascals are described. Methods of making such glass bubbles and compositions and articles such as sheet molding compounds and dielectric layers prepared from such glass bubbles are also described.

Novel cellular solids and foams from amorphous materials with a glass transition temperature (T.sub.g) and methods of forming such materials are provided. In particular, foams are formed by expanding or compressing hollow spheres made of a high strength amorphous material, which is defined as a material having high strength characteristics, but also possessing a glass transition within a confined space. Using such a method, it has been unexpectedly found that it is possible to make cellular structures, including both open and closed cell foams, with customizable properties from materials that have been inaccessible with conventional methods. Moreover, based on calculations high specific strengths and stiffnesses are expected.

Glass microbubbles include on an average weight basis: from 25.0 to 37.4 percent by weight of silicon; from 5.7 to 8.6 percent by weight of calcium; from 5.2 to 14.9 percent by weight, on a total combined weight basis, of at least one of sodium or potassium; from 0.3 to 0.9 percent of boron; and from 0.9 to 2.6 percent of phosphorus, wherein the weight ratio of phosphorus to boron is in the range of from 1.4 to 4.2, and wherein the glass microbubbles comprise less than 0.4 percent by weight of zinc. A raw product including the glass microbubbles, and methods of making the raw product are also disclosed.

Provided are methods of manufacturing hollow glass microspheres where a feed composition comprising a glass powder and a blowing agent entrained in the glass powder is introduced into an opening at a first end of a vertically-aligned furnace. Agglomerated glass, unmelted oxides, or natural glassy materials can be used in place of, or in addition to, the glass powder in the feed composition.

The present invention provides a method of manufacturing a three-dimensional product having uniform mechanical properties using an SLS 3D printer including the steps of: preparing a mixed powder material by mixing resin powder and glass bubbles, wherein the specific gravity of the glass bubbles is from about 0.8 to about 1.2 times that of the resin powder; supplying the mixed powder material to the 3D printer using a roller; and selectively sintering the mixed powder material by irradiating the powder material using a laser based on 3D data of the product to be manufactured.

Novel cellular solids and foams from amorphous materials with a glass transition temperature (T.sub.g) and methods of forming such materials are provided. In particular, foams are formed by expanding or compressing hollow spheres made of a high strength amorphous material, which is defined as a material having high strength characteristics, but also possessing a glass transition within a confined space. Using such a method, it has been unexpectedly found that it is possible to make cellular structures, including both open and closed cell foams, with customizable properties from materials that have been inaccessible with conventional methods. Moreover, based on calculations high specific strengths and stiffnesses are expected.

The present invention relates to compositions with self-cleaning properties. More particularly, the invention concerns coatings or paints comprising particles coated with a catalytically active composition. In particular, a self-cleaning coating composition (paint) is provided, comprising micro-sized particles coated with a functional layer, wherein the micro-sized particles are hollow or solid beads, or any combination/ratio of hollow and solid beads, wherein the beads comprise one or more material(s) selected from ceramic material(s); polymeric material(s); cermet material(s); metallic material(s); pigmented material(s); light-absorbing and/or light reflecting material(s); including any combination thereof, wherein said layer is covalently bound to said particles, wherein the photocatalytic layer comprises TiO.sub.2 in the crystal form of anatase; and wherein the coating composition (paint) comprises less than 0.1 anatase particles derived/released from the micro-sized beads, determined as weight/weight of released anatase/total amount of anatase. The invention provides paint essentially without presence of unbound anatase crystals which is highly undesired, as it is believed that their presence has a negative influence on essential components of the paint, such as binder, pigment and/or additives and furthermore, anatase may cause eye, skin, and respiratory tract irritation.

A composite particle includes a discrete, hollow, ceramic spheroid and a fluoropolymer layer disposed thereon. The fluoropolymer is a homopolymer or copolymer of a perfluoroalkyl vinyl ether; a perfluoroalkoxy vinyl ether; at least one fluoroolefin independently represented by formula C(R).sub.2CFRf, wherein Rf is fluorine or a perfluoroalkyl having from 1 to 8 carbon atoms and R is hydrogen, fluorine, or chlorine; or a combination thereof. Methods of making the composite particles, composite materials, and articles including them are also disclosed.

A glass bubble includes a hollow glass body having an outer surface with a diameter of between about 16 micrometers and about 25 micrometers and a surface roughness of about 0.01% to about 0.1% of that diameter. A low density sheet molding compound incorporating a plurality of glass bubbles and resin is also disclosed.