Method for producing hydrophobic aerogels
AssigneeThe Regents of the University of California
InventorsLawrence W. Hrubesh, John F. Poco, Paul R. Coronado
Life of this patent
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Abstract
A method for treating a dried monolithic aerogel containing non-dispersed particles, with an organometallic surface modifying agent to produce hydrophobic aerogels. The dried, porous hydrophobic aerogels contain a protective layer of alkyl groups, such as methyl groups, on the modified surfaces of the pores of the aerogel. The alkyl groups at the aerogel surface typically contain at least one carbon-metal bond per group.
Claims20
A method for increasing the hydrophobicity of a dried fully prepared non-dispersed, monolithic aerogel, said method comprising:
- homogenously contacting a dried aerogel with a gaseous surface modifying agent comprising an organometallic halogen composition to produce a resultant organometallic aerogel;
- and
- removing a halogen-containing by-product composition from said resultant organometallic aerogel to produce a product aerogel.
A method for treating a dried aerogel, said method comprising:
- removing organic molecules from a dried monolithic, transparent aerogel having a surface area greater than 200 m.sup.2 /g and a porosity having at least 90% of the pores of diameter less than 1000 angstroms;
- contacting said dried aerogel with a surface modifying agent comprising at least two alkyl group and at least one halogen atom linked to a metal atom to produce a resultant organometallic aerogel;
- and
- removing a hydrogen-halogen by-product composition from said resultant organometallic aerogel.
A method for increasing the hydrophobicity of a dried metal-oxide aerogel, said method comprising:
- heating a dried aerogel in the range from 50 degrees C. to 500 degrees C. to remove organic molecules from a surface of said dried aerogel;
- contacting said surface of said dried aerogel with a surface modifying agent comprising at least three alkyl group and a halogen atom linked to a metal atom under an elevated pressure from above 1 to about 500 atmospheres to produce a resultant organometallic aerogel;
- and
- removing a hydrogen-halogen composition from said resultant organometallic aerogel.
A method for increasing the hydrophobicity of a dried fully prepared aerogel essentially free of dispersed particles, said method consisting essentially of:
- contacting a dried, monolithic aerogel essentially free of dispersed particles with a surface modifying agent comprising an organometallic halogen composition to produce a resultant organometallic aerogel;
- and
- removing a hydrogen-halogen composition from said resultant organometallic aerogel to produce a product aerogel.
Dependencies are inferred from the claim text.