Tailoring new covalent organic framework for highly efficient iodine capture

Patent metadata

Field	Value
Publication number	US-2025033025-A1
Application number	US-202318227807-A
Country	US
Kind code	A1
Filing date	Jul 28, 2023
Priority date	Jul 28, 2023
Publication date	Jan 30, 2025
Grant date	—

Abstract

The phosphazene covalent organic framework (COF) is a material with high efficiency to improve the removal of iodine from nuclear waste. The COF can be obtained by a solvothermal reaction of hexa(4-formyl-phenoxy)cyclotriphosphazene and 1,3,6,8-tetra(aminophenyl)pyrene. The resulting three-dimensional phosphazene COF has iodine uptakes as high as 9.4 g g−1 due to its 3D framework with higher specific surface areas and interconnected channels.

First claim

1 : A method for making a phosphazene covalent organic framework (MA-COF) comprising:
obtaining a hexa(4-formyl-phenoxy)cyclotriphosphazene having the formula:

obtaining a 1,3,6,8-tetra(aminophenyl)pyrene having the formula:

placing the hexa(4-formyl-phenoxy)cyclotriphosphazene and the 1,3,6,8-tetra(aminophenyl)pyrene in separate vessels, then adding a solvent to each respective vessel and sonicating each respective vessel to obtain a hexa(4-formyl-phenoxy)cyclotriphosphazene homogenous dispersion and a 1,3,6,8-tetra(aminophenyl)pyrene homogenous dispersion;
adding the hexa(4-formyl-phenoxy)cyclotriphosphazene homogenous dispersion to the vessel containing the 1,3,6,8-tetra(aminophenyl)pyrene homogenous dispersion to obtain a suspension;
adding acetic acid to the suspension and leaving the resulting mixture in an autoclave undisturbed for at least about 7 days at a temperature of about 110° C. to about 130° C. to obtain a solid;
collecting the solid by filtration and drying the solid to obtain the phosphazene covalent organic framework (MA-COF) having the formula:

2 : The method of claim 1 , wherein the hexa(4-formyl-phenoxy)cyclotriphosphazene and the 1,3,6,8-tetra(aminophenyl)pyrene are used in an about 1:3 molar ratio.

3 : The method of claim 1 , wherein after the hexa(4-formyl-phenoxy)cyclotriphosphazene homogenous dispersion is added to the vessel containing the 1,3,6,8-tetra(aminophenyl)pyrene homogenous dispersion and acetic acid is also added to the vessel containing the 1,3,6,8-tetra(aminophenyl)pyrene homogenous dispersion.

4 : The method of claim 1 , wherein the solvent added to the respective vessels is 1,2-dichlorobenzene and n-butanol.

5 : The method of claim 1 , wherein the solid collected by filtration is washed with DMF, acetone, and THF separately before drying.

6 : The method of claim 1 , wherein the phosphazene covalent organic framework (MA-COF) is obtained as a yellowish crystalline solid.

7 : The method of claim 1 , wherein the hexa(4-formyl-phenoxy)cyclotriphosphazene is obtained by reacting p-hydroxybenzaldehyde and hexachlorocyclotriphosphazene.

8 : The method of claim 7 , wherein the p-hydroxybenzaldehyde and the hexachlorocyclotriphosphazene are separately dissolved in acetonitrile before being reacted with each other.

9 : The method of claim 8 , wherein the reaction of the p-hydroxybenzaldehyde and the hexachlorocyclotriphosphazene occurs for about 30 min at about 140° C. using microwave protocol.

10 : The method of claim 1 , wherein the 1,3,6,8-tetra(aminophenyl)pyrene is obtained by reacting 1,2,6,8-tetrabromopyrene with 4-aminophenylboronic acid pinacol ester.

11 : The method of claim 10 , wherein the reaction of the 1,2,6,8-tetrabromopyrene with 4-aminophenylboronic acid pinacol ester is conducted by preparing a solution of the 1,3,6,8-tetrabromopyrene and the 4-aminophenylboronic acid pinacol ester with Na 2 CO 3 and Pd(PPh 3 ) 4 in 1,4-dioxane and water.

12 : The method of claim 11 , wherein the reaction of the 1,2,6,8-tetrabromopyrene with 4-aminophenylboronic acid pinacol ester occurs while the solution is heated to reflux for about three days.

13 : A phosphazene covalent organic framework (MA-COF) having the formula:

14 : The phosphazene covalent organic framework (MA-COF) of claim 13 , which is stable in a solvent selected from the group consisting of HCl, NaOH, DMF, DMSO, ethanol, boiling water, and any combination thereof.

15 : The phosphazene covalent organic framework (MA-COF) of claim 13 , having an iodine adsorption capacity of about 9.4 g g −1 .

16 : A method for removing iodine from liquid or vapor, the method comprising:
contacting the phosphazene covalent organic framework (MA-COF) of claim 13 with an iodine-containing liquid or vapor; and adsorbing the iodine from the iodine-containing liquid or vapor onto the phosphazene covalent organic framework (MA-COF).

17 : The method of claim 16 , wherein the phosphazene covalent organic framework (MA-COF) removes about 97% of the iodine from the iodine-containing liquid or vapor.

18 : The method of claim 16 , wherein the phosphazene covalent organic framework (MA-COF) is capable of being reused in the method at least five times.

19 : The method of claim 16 , wherein, after the iodine is adsorbed on the phosphazene covalent organic framework (MA-COF), the iodine can be released from the phosphazene covalent organic framework (MA-COF) at an efficiency of about 73% or greater within about 10 minutes.

20 : The method of claim 16 , wherein, after the iodine is adsorbed on the phosphazene covalent organic framework (MA-COF), the iodine can be released from the phosphazene covalent organic framework (MA-COF) at an efficiency of about 80% or greater within about 60 minutes.

Assignees

• Univ United Arab Emirates

Inventors

• Alneyadi Shaikha
• Alhassani Mohammed Taleb Khamis
• Aleissaee Ali Saeed Saif
• Khalaf Abdullah Ayman
• Alteneiji Abdulrahman Abdullah Alhaj
• Jama Sultan Ali
• Alyaarbi Yaser Yusri Yaser

Classifications

• B01D2258/02

  Other waste gases · CPC title

• B01D53/685

  by treating the gases with solids · CPC title

• B01J20/3085

  Chemical treatments not covered by groups B01J20/3007 - B01J20/3078 · CPC title

• G21F9/12

  by absorption; by adsorption; by ion-exchange · CPC title

• B01D15/203

  Equilibration or regeneration · CPC title