Production method for core-shell porous silica particles

Patent metadata

Field	Value
Publication number	US-11964253-B2
Application number	US-201917252042-A
Country	US
Kind code	B2
Filing date	Jun 17, 2019
Priority date	Jun 15, 2018
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

Provided is a production method for core-shell porous silica particles, the production method including: a preparation step of preparing an aqueous solution comprising non-porous silica particles, a cationic surfactant, a basic catalyst, an electrolyte, and an alcohol; a shell precursor formation step at adding a silica source to the aqueous solution to form a shell precursor on a surface of the non-porous silica particles; and a shell formation step of removing the cationic surfactant from the shell precursor to form a porous shell.

First claim

The invention claimed is:

1. A method for producing core-shell porous silica particles, the method comprising:
a preparation step of preparing a dispersion comprising an aqueous solution comprising a cationic surfactant, a basic catalyst, an electrolyte, an alcohol, and non-porous silica particles dispersed in the aqueous solution;
a shell precursor formation step of adding a silica source to the dispersion to form a shell precursor on a surface of the non-porous silica particles; and
a shell formation step of removing the cationic surfactant from the shell precursor to form a porous shell.

2. The production method according to claim 1 , wherein a concentration of the electrolyte the aqueous solution is from 1 mM to 4 mM.

3. The production method according to claim 1 , wherein the electrolyte is a chlorine-based electrolyte, a bromine-based electrolyte, or an iodine-based electrolyte.

4. The production method according to claim 3 , wherein the chlorine -based electrolyte is sodium chloride, potassium chloride or lithium chloride.

5. The production method according to claim 3 , wherein the bromine -based electrolyte is sodium bromide, potassium bromide, or lithium bromide.

6. The production method according to claim 3 , wherein the iodine-based electrolyte is sodium iodide, potassium iodide, or lithium iodide.

7. The production method according to claim 1 , wherein the cationic surfactant is a hexadecyltrimethylammonium halide or an octadecyltrimethylammonium halide.

8. The production method according to claim 1 , wherein the basic catalyst is ammonia.

9. The production method according to claim 1 , wherein the alcohol is ethanol.

10. The production method according to claim 1 , wherein the silica source is tetraethoxysilane.

11. The production method according to claim 1 , wherein the non-porous silica particles has a volume average particle size, Dv, of 20 nm to 1.5 μm.

12. The production method according to claim 1 , wherein the non-porous silica particles has a volume average particle size, Dv, of 40 nm to 1.0 μm.

13. The production method according to claim 1 , wherein a concentration of the electrolyte in the aqueous solution is from 1 mM to 8 mM.

14. The production method according to claim 1 , wherein a specific surface area of the non-porous silica particles is 50 m 2 /g or less.

Assignees

• Univ Tohoku
• Daicel Corp

Inventors

• Nagao Daisuke
• Ishii Haruyuki
• Ishikawa Shunho

Classifications

• B01J20/103 Primary

  comprising silica · CPC title

• B01J20/28021

  Hollow particles, e.g. hollow spheres, microspheres or cenospheres · CPC title

• B01J20/283

  based on silica · CPC title

• B01J20/3204

  Inorganic carriers, supports or substrates · CPC title

• B01J20/3214

  characterised by the method for obtaining this coating or impregnating · CPC title