Method for producing core-shell porous silica particles

Patent metadata

Field	Value
Publication number	US-12030783-B2
Application number	US-201917271704-A
Country	US
Kind code	B2
Filing date	Aug 13, 2019
Priority date	Aug 28, 2018
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

An object of the present disclosure is to provide a method for producing a core-shell porous silica particle with an increased thickness of the shell. The object is met by a method for producing a core-shell porous silica particle, the method including the following steps: (a) preparing; (b) forming a shell precursor; (c) forming a shell; (d) preparing; (e) forming a shell precursor; and (f) forming a shell; wherein the steps (d) through (f) are further repeated one to three times, in which case the step of forming a shell described in step (d) refers to step (f).

First claim

The invention claimed is:

1. A production method for a core-shell porous silica particle, the method comprising:
(a) preparing an aqueous solution containing a non-porous silica particle, a cationic surfactant, a basic catalyst, and an alcohol;
(b) adding a silica source to the aqueous solution to form a shell precursor on a surface of the non-porous silica particle;
(c) removing the cationic surfactant from the shell precursor and forming a porous shell;
(d) preparing an aqueous solution containing a porous silica particle resulting from the forming the porous shell, a cationic surfactant, a basic catalyst, and an alcohol;
(e) adding a silica source to the aqueous solution to form a shell precursor on a surface of the porous silica particle; and
(f) removing the cationic surfactant from the shell precursor and forming a porous shell; wherein
the steps (d) to (f) are further repeated one to three times, in which case the “forming the porous shell” in step (d) refers to the “forming a porous shell” in step (f).

2. The production method according to claim 1 , wherein the cationic surfactant is at least one selected from the group consisting of a hexadecyltrimethylammonium halide and an octadecyltrimethylammonium halide.

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

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

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

6. The production method according to claim 1 , wherein:
the cationic surfactant is a hexadecyltrimethylammonium halide;
the basic catalyst is ammonia;
the alcohol is ethanol; and
the silica source is tetraethoxysilane.

7. The production method according to claim 6 , wherein the steps (d) to (f) are repeated one time.

Assignees

• Univ Tohoku
• Daicel Corp

Inventors

• Fukuda Daisuke
• Nagao Daisuke
• Ishii Haruyuki
• Ishikawa Shunho

Classifications

• C01P2006/16

  Pore diameter · CPC title

• C01P2006/14

  Pore volume · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2004/82

  two phases having the same anion, e.g. both oxidic phases · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title