A microsphere of oxide has an opening on its surface connected to a hollow core inside, forming a cavity. The oxide the microsphere is made of is selected from the group consisting of alumina, silica, zirconia, magnesium oxide, calcium oxide and titania. The microsphere of oxide shows better mass and heat transfer characteristics, and has strength significantly higher than that of existing products with similar structures. A FT synthesis catalyst has the microsphere of oxide as a support and an active metal component disposed on the support. The active metal component is one or more selected from the group consisting of Co, Fe, and Ru.

To provide hollow silica particles having a dense silica shell layer. A method for producing hollow silica particles, which comprises: adjusting the pH of an oil-in-water emulsion containing an aqueous phase, an oil phase and a surfactant to at most 3.0 and adding a first silica material to the oil-in-water emulsion, adding a second silica material to the emulsion having the first silica material added, at its pH of at least 8, in the presence of alkali metal ions, to obtain a hollow silica precursor dispersion, and obtaining a hollow silica precursor from the hollow silica precursor dispersion and obtaining hollow silica particles from the hollow silica precursor.

To provide hollow silica particles having a dense silica shell layer.

A method for producing hollow silica particles, which comprises: adjusting the pH of an oil-in-water emulsion containing an aqueous phase, an oil phase and a surfactant to at most 3.0 and adding a first silica material to the oil-in-water emulsion, adding a second silica material to the emulsion having the first silica material added, at its pH of at least 8, in the presence of alkali metal ions, to obtain a hollow silica precursor dispersion, and obtaining a hollow silica precursor from the hollow silica precursor dispersion and obtaining hollow silica particles from the hollow silica precursor.

This invention describes the encapsulation of and self-assembly of meso (nano) porous silica particles from inorganic an inexpensive silica precursor, sodium silicate. The particles have a well defined shape, high surface area, and high uniformity of the pore size, the properties that are typically found for high quality mesoporous material synthesized from organic silica precursors. The disclosure illustrates a synthesis of hard spheres, discoids, and a mixture comprising discoids, gyroids and fibers, termed as origami.

The object of the present invention is to provide silica particles which can provide a silica particle dispersion exhibiting excellent uniformity. The present invention is silica particles having an average primary particle diameter d.sub.BET calculated from a specific surface area by a BET method of 1 nm or more and 100 nm or less and a ratio (d.sub.DLS/d.sub.BET) of an average secondary particle diameter d.sub.DLS measured by a dynamic light scattering method to the d.sub.BET of 1.2 or less. The silica particles of the present invention preferably have a coefficient of variation in a particle diameter measured using a transmission electron microscope at a magnification of 200,000 of 20% or less.

The object of the present invention is to provide silica particles which can provide a silica particle dispersion exhibiting excellent uniformity. The present invention is silica particles having an average primary particle diameter d.sub.BET calculated from a specific surface area by a BET method of 1 nm or more and 100 nm or less and a ratio (d.sub.DLS/d.sub.BET) of an average secondary particle diameter d.sub.DLS measured by a dynamic light scattering method to the d.sub.BET of 1.2 or less. The silica particles of the present invention preferably have a coefficient of variation in a particle diameter measured using a transmission electron microscope at a magnification of 200,000 of 20% or less.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, optionally in the presence of an aluminium compound; wherein at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation. It also relates to a novel precipitated silica and to its uses.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, optionally in the presence of an aluminium compound; wherein at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation. It also relates to a novel precipitated silica and to its uses.

Silica particles having a d50 median particle size from 8 to 20 μm, a sphericity factor (S.sub.80) of at least 0.9, a BET surface area from 0.1 to 8 m.sup.2/g, a total mercury intrusion pore volume from 0.35 to 0.8 cc/g, and a loss on ignition from 3 to 7 wt. %, are disclosed, as well as methods for making these silica particles, and dentifrice compositions containing the silica particles.

Silica particles having a d50 median particle size from 8 to 20 μm, a sphericity factor (S.sub.80) of at least 0.9, a BET surface area from 0.1 to 8 m.sup.2/g, a total mercury intrusion pore volume from 0.35 to 0.8 cc/g, and a loss on ignition from 3 to 7 wt. %, are disclosed, as well as methods for making these silica particles, and dentifrice compositions containing the silica particles.