Rapidly dissolvable nanoparticles
AssigneePall Corporation
InventorsShane Edward Harton, Yolando David
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Abstract
Disclosed are silica nanoparticles that are suitable as templates for preparing membranes of controlled pore sizes and pore arrangements. The silica nanoparticles have a density of about 1.96 g/cm3 or less. Also disclosed is a method of preparing such nanoparticles which involves reacting an orthosilicate and an alcohol or a mixture of alcohols in an aqueous medium in the presence of a salt of the metal or a metalloid compound, optionally in combination with ammonium hydroxide, isolating the resulting nanoparticles, and treating the resulting particles with an acid.
Claims19
Silica nanoparticles having a diameter of about 50 nm to about 1000 nm, a particle density of about 1.96 g/cm3 or less, and a rate of dissolution in 1N KOH solution of more than 10 nm/min, wherein the rate is measured by mixing 1-5 mg/mL silica nanoparticles in 1N aqueous KOH solution at 25° C. and measuring the change in diameter as a function of time by the Dynamic Light Scattering method or measuring the turbidity decay as a function of time using a nephelometric turbidity meter.
A method of preparing silica nanoparticles having a diameter of about 50 nm to about 1000 nm, a particle density of about 1.96 g/cm3 or less, and a rate of dissolution in 1N KOH solution of more than 10 nm/min, wherein the rate is measured by mixing 1-5 mg/mL silica nanoparticles in 1N aqueous KOH solution at 25° C. and measuring the change in diameter as a function of time by the Dynamic Light Scattering method or measuring the turbidity decay as a function of time using a nephelometric turbidity meter, said method comprising:
- (a) reacting an orthosilicate and an alcohol or a mixture of alcohols in an aqueous medium in the presence of a salt of a metal of Group Ia or Group IIa or in the presence of a metalloid compound, optionally in combination with ammonium hydroxide,
- b) isolating the resulting nanoparticles, and
- (c) treating the nanoparticles from (b) with an acid.
Dependencies are inferred from the claim text.