A method can include milling a plurality of silicon particles to form a plurality of milled silicon particles. The milled silicon particles can optionally include collecting the milled silicon particles, powdering the milled silicon particles, and milling the milled silicon particles a second time.

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.

A silicon material can include a silicon aggregate comprising a plurality of porous silicon nanoparticles welded together. The silicon aggregate can optionally have a polyhedral morphology. A method can include: receiving a plurality of porous silicon nanoparticles and cold welding the plurality of porous silicon nanoparticles into an aggregated silicon particle.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.

There are disclosed aqueous pigment dispersions containing dispersant-improving-agents, and methods of preparing and using the same.

A method may include wet ball milling a plurality of iron nitride nanoparticles in the presence of a surface active agent to modify a surface of the plurality of iron nitride nanoparticles and form a plurality of surface-modified iron nitride nanoparticles for a variety of biomedical applications and soft magnetic materials related applications.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO.sub.2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m.sup.2/g of the specific surface area of the particle to be coated.