Formulation and method for preparing gels comprising hydrous aluminum oxide
View Patent ↗Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.
1. A formulation for preparing gels, the formulation comprising:
a metal salt comprising aluminum in the form of aluminum nitrate;
an organic base; and
a complexing agent,
wherein a mole ratio of the organic base to the aluminum ranges from greater than 0 to about 3; and a mole ratio of the complexing agent to the aluminum is at least about 1.
2. The formulation of claim 1 , wherein a mole ratio of the organic base to the aluminum ranges from about 0.1 to about 2.8.
3. The formulation of claim 1 , wherein a concentration of the aluminum ranges from about 0.7 M to about 1.7 M.
4. The formulation of claim 1 , wherein a concentration of the organic base ranges from about 0.1 M to about 2.5 M.
5. The formulation of claim 1 , further comprising a source of hydroxide.
6. The formulation of claim 5 , wherein a mole ratio of the hydroxide to the aluminum ranges from greater than 0 to about 2.
7. The formulation of claim 5 , wherein the source of hydroxide comprises ammonium hydroxide.
8. The formulation of claim 1 , wherein the organic base comprises hexamethylenetetramine, and the complexing agent comprises urea.
9. The formulation of claim 1 , wherein a concentration of the aluminum ranges from about 0.7 M to about 1.7 M, a concentration of the organic base ranges from about 0.1 M to about 2.5 M, the organic base comprises hexamethylenetetramine and the complexing agent comprises urea.
10. The formulation of claim 9 , further comprising a source of hydroxide, wherein a mole ratio of the hydroxide to the aluminum ranges from greater than 0 to about 2, and the source of hydroxide comprises ammonium hydroxide.
11. The formulation of claim 9 wherein the mole ratio of the organic base to the aluminum ranges from about 0.1 to about 2.8.
12. The formulation of claim 11 , further comprising a source of hydroxide, wherein a mole ratio of the hydroxide to the aluminum ranges from greater than 0 to about 2, and the source of hydroxide comprises ammonium hydroxide.
13. A formulation for preparing gels, the formulation comprising:
a metal salt comprising aluminum in the form of aluminum nitrate;
an organic base; and
a complexing agent,
wherein a concentration of the aluminum ranges from about 0.7 M to about 1.7 M.
14. The formulation of claim 13 , wherein a concentration of the organic base ranges from about 0.1 M to about 2.5 M.
15. The formulation of claim 13 , further comprising a source of hydroxide, wherein a concentration of the hydroxide ranges from about 0.3 M to about 3.5 M.
16. A method of preparing gels comprising hydrous aluminum oxide, the method comprising heating a volume of a formulation to a temperature sufficient to induce gel formation, wherein the formulation comprises:
a metal salt comprising aluminum in the form of aluminum nitrate;
an organic base; and
a complexing agent,
wherein a mole ratio of the organic base to the aluminum ranges from greater than 0 to about 3; and a mole ratio of the complexing agent to the aluminum is at least about 1.
17. The method of claim 16 , wherein the volume of the formulation is heated to a temperature of at least about 60° Celsius.
18. The method of claim 17 , wherein the volume of the formulation is heated to a temperature of about 60° Celsius to about 90° Celsius.