Hierarchical siliceous mesosilicalite nanocarrier

Patent metadata

Field	Value
Publication number	US-11096911-B2
Application number	US-201816138591-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Apr 4, 2017
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A mesosilicalite nanocarrier having a hierarchical silicalite characterized by a molar ratio of aluminum to silica in a range of 1:3000 to 1:1000. The hierarchical silicalite includes mesopores of a hexagonal structure, and micropores of silicalite structure with a microporous volume in the range of 0.05 cc/g to 0.1 cc/g. The nanocarrier has a mesophase content in the range of 30 wt % to 70 wt %, a microphase content in the range of 30 wt % to 70 wt %, and a mean pore diameter in the range of 1.5 nm to 5.5 nm. A method of preparing the stable mesosilicalite nanocarrier with hierarchical micro/mesopores to load an antioxidant or drug for targeted drug delivery is also described.

First claim

The invention claimed is:

1. A method of preparing a mesosilicalite nanocarrier comprising:
a hierarchical silicalite having a silica to aluminum molar ratio in a range of 1000:1 to 3000:1, comprising:
a mesophase with mesopores of a hexagonal structure; and
a microphase with micropores of a microporous volume in the range of 0.05 cc/g to 0.1 cc/g;
wherein the mesophase content is in the range of 30% to 70% relative to a total weight of the nanocarrier, and the microphase content is in the range of 30% to 70% relative to the total weight of the nanocarrier; and
wherein a mean pore diameter of the mesosilicalite nanocarrier is in the range of 1.5 nm to 5.5 nm,

the method comprising:
mixing a silica source with a template to form a first mixture,
hydrothermally aging the first mixture at a temperature of 150° C.-200° C. for 24 hours to 86 hours to produce an aged first mixture;
drying the aged first mixture to form a silicalite;
treating the silicalite with an alkaline solution and a surfactant to form a second mixture;
hydrothermally aging the second mixture at a temperature of 60° C.-120° C. for 12 hours to 36 hours at a rate of 3° C./min to 6° C./min to form an aged second mixture;
neutralizing a pH of the aged second mixture;
hydrothermally aging the aged second mixture at a temperature of 60° C.-120° C. for 12 hours to 36 hours at a rate of 3° C./min to 6° C./min to produce a third mixture; and
drying the third mixture to form the mesosilicalite nanocarrier.

2. The method of claim 1 , wherein the silica source is colloidal silica.

3. The method of claim 2 , wherein the colloidal silica has a surface area in the range of 120 m 2 /g to 150 m 2 /g.

4. The method of claim 3 , wherein the colloidal silica has a density in the range of 1.15 g/mL to 1.35 g/mL at 20° C.-30° C.

5. The method of claim 1 , wherein the silicalite is a crystal having a crystal size of 1 μm to 5 μm.

6. The method of claim 1 , further comprising calcining the silicalite after the drying at a temperature in the range of 545° C.-605° C. for 5 hours to 11 hours and at a rate of 3° C./min to 6° C./min.

7. The method of claim 1 , further comprising calcining the mesosilicalite nanocarrier in a temperature range of 545° C.-605° C.

8. The method of claim 1 , wherein the template is tetrapropylammonium hydroxide.

9. The method of claim 1 , wherein the surfactant is at least one of an alkylammonium halide or an alkylammonium hydroxide.

10. The method of claim 9 , wherein the surfactant is cetyl trimethylammonium bromide.

11. The method of claim 1 , wherein the alkaline solution comprises a base selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and barium hydroxide in a concentration range of 0.1 M to 0.8 M.

12. The method of claim 1 , wherein the alkaline solution consists of sodium hydroxide in water at a concentration of 0.2 M to 0.7 M.

13. The method of claim 1 , further comprising loading the antioxidant into the mesosilicate nanocarrier, the loading comprising:
drying the mesosilicate nanocarrier at 100° C.-120° C. for 72 hours to 86 hours; and
mixing the dried mesosilicate nanocarrier with a solution of the antioxidant for 12 hours to 36 hours at 23° C.-30° C. to form the mesosilicate nanocarrier loaded with the antioxidant at 10% to 50% by weight of a total weight of the mesosilicate nanocarrier.

14. The method of claim 13 , wherein the solution of the antioxidant is an acidic aqueous solution.

15. The method of claim 13 , wherein the solution of the antioxidant has an antioxidant concentration of 0.25 g/L to 15 g/L.

Assignees

• Univ Imam Abdulrahman Bin Faisal

Inventors

• Jermy B Rabindran
• Ravinayagam Vijaya

Classifications

• A61K31/192 Primary

  having aromatic groups, e.g. sulindac, 2-aryl-propionic acids, ethacrynic acid  {(cannabinoids A61K31/658)} · CPC title

• B01J20/10

  comprising silica or silicate · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title

• B01J20/28073

  being in the range 0.5-1.0 ml/g · CPC title

• C01B37/005

  Silicates, i.e. so-called metallosilicalites or metallozeosilites · CPC title