Methods of forming cement pastes, methods of forming concrete, and methods of forming other compositions using mineral particles formed from the one or more of biomineralizing microorganisms and biomineralizing microorganisms. Desired features, such as size and morphology, can be controlled by controlling growth parameters of the biomineralizing microorganisms and biomineralizing microorganisms.

A cristobalite includes: a d50 particle size selected within a range of from 1 μm to 15 μm; an L color coordinate of greater than 96; a color coordinate of less than 1; and a b color coordinate of 1 or less, in which the cristobalite is a powder. Also provided are compositions containing the cristobalite, coatings formed with compositions, and methods of preparing cristobalite.

Provided is a silica that exhibits a high matting property when utilized as a matting agent for a paint, and can also suppress the occurrence of cloudiness. The silica has an aggregated structure in which primary particles are aggregated, has a particle diameter ratio R represented by the following equation (1) of from 4.3 to 5.2, has an absorbance of 0.6 or less for light having a wavelength of 700 nm as an aqueous dispersion having a concentration of 1.48 mass %, and has a particle density measured with a He pycnometer of 2.18 g/cm.sup.3 or more: Equation (1) R=.sup.LD50/.sup.CD50 (in the equation (1), .sup.LD50 represents a volume-based 50% cumulative particle diameter (μm) of the silica measured based on a laser diffraction/scattering method, and .sup.CD50 represents a volume-based 50% cumulative particle diameter (μm) of the silica measured based on a Coulter counter method).

The present invention relates to a method of preparing a high hydrophobic silica aerogel having a low tap density and a hydrophobic silica aerogel prepared thereby. The method of preparing a hydrophobic silica aerogel according to the present invention may have good productivity and economic efficiency, because preparation time is reduced by simultaneously performing surface modification and solvent substitution in a single step, and may control a degree of hydrophobicity of the prepared silica aerogel by controlling a surface modification reaction by including a step of adding ammonium hydroxide. Thus, a hydrophobic silica aerogel having excellent physical properties, such as tap density and specific surface area, as well as high hydrophobicity obtained by controlling the degree of hydrophobicity may be prepared.

A composite filler comprising thermally processed porous inorganic mixed particles of silica and at least one heteroparticle selected from the group consisting of zirconia, hafnia, or yttria and a polymer occupying the pores of the porous inorganic mixed particles, wherein the porous inorganic mixed particles are thermally processed at a temperature of from 650 to 900° C., as well as a dental restorative comprising a resin and a composite filler, and optionally other fillers, wherein said resin has a refractive index that increases upon curing, and wherein the opacities of the both uncured and cured restorative are less than 45.

This invention relates to a defoamer active. The defoamer active may include hydrophobized silica particles obtained by treating silica particles with a hydrophobilizing agent. The silica particles may have a BET surface of less than about 150 m.sup.2/g, a surface pH of at least about 10, and a median particle size ranging from about 2 μm to about 50 μm. The carbon content of the hydrophobized silica particles may not be more than 3%.

A composite filler comprising thermally processed porous inorganic mixed particles of silica and at least one heteroparticle selected from the group consisting of zirconia, hafnia, or yttria and a polymer occupying the pores of the porous inorganic mixed particles, wherein the porous inorganic mixed particles are thermally processed at a temperature of from 650 to 900° C., as well as a dental restorative comprising a resin and a composite filler, and optionally other fillers, wherein said resin has a refractive index that increases upon curing, and wherein the opacities of the both uncured and cured restorative are less than 45.

A method for manufacturing a diatomaceous earth functional filler product with detectable or non-detectable crystalline silica includes the steps of: selecting a diatomaceous earth ore; simultaneously milling and flash-drying the diatomaceous earth ore; beneficiating the milled and flash-dried diamtomaceous earth ore; blending the beneficiated diatomaceous earth ore with a fluxing agent; calcining the blended diatomaceous earth ore and fluxing agent to produce an initial diatomaceous earth powder; air-classifying the initial diatomaceous earth powder to produce a first fraction including the diatomaceous earth functional filler product and a second fraction including coarse particles; further milling the coarse particles to produce additional diatomaceous earth powder; and re-circulating the additional diatomaceous earth powder to blend the additional diatomaceous earth powder with the initial diatomaceous earth powder.

A paint system contains an anti-fouling metal oxide and a fumed silica, wherein the fumed silica has a BET surface area of 150 to 400 m.sup.2/g, a tamped density of 100 to 300 g/l, and a thickening of less than 500 mPas, in which the percentage by weight of silica≤the percentage by weight of the metal and/or oxide thereof, based on the total weight of the paint system. The paint system also contains at least one water-binding organic and/or inorganic filler.

A composite filler comprising thermally processed porous inorganic mixed particles of silica and at least one heteroparticle selected from the group consisting of zirconia, hafnia, or yttria and a polymer occupying the pores of the porous inorganic mixed particles, wherein the porous inorganic mixed particles are thermally processed at a temperature of from 650 to 900 C., as well as a dental restorative comprising a resin and a composite filler, and optionally other fillers, wherein said resin has a refractive index that increases upon curing, and wherein the opacities of the both uncured and cured restorative are less than 45.