Electrically conducting ruthenium dioxide aerogel composite

• US 6,649,091 B2
• Filed: 09/19/2001
• Issued: 11/18/2003
• Est. Priority Date: 12/01/1999
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Long, Jeffery W., Berry, Alan D., Merzbacher, Celia I., Ryan, Joseph V., Rolison, Debra R.
• Primary Examiner(s): KOPEC, MARK T
• Application Number:
  US09/955,022
• Publication Number:
  US 20030062512A1
• Time in Patent Office: 790 Days
• Field of Search: 252/518.1, 252/521.3, 423/22, 423/592
• US Class Current: 252/521.3
• CPC Class Codes: H01B 1/14 Conductive material dispersed in non-conductive inorganic material

Abstract

An electrically conducting composite is made by providing an aerogel structure of nonconducting material, exposing the aerogel structure to a mixture of RuO₄ and a nonpolar solvent in an inert atmosphere, wherein the mixture is held initially at a first temperature that is below the temperature at which RuO₄ decomposes into RuO₂ in the nonpolar solvent and in the presence of the aerogel, and allowing the mixture to warm to a second temperature that is above the temperature at which RuO₄ decomposes to RuO₂ in the nonpolar solvent and in the presence of the aerogel, wherein the rate of warming is controlled so that as the mixture warms and the RuO₄ begins to decompose into RuO₂, the newly formed RuO₂ is deposited throughout the aerogel structure as a three-dimensionally networked conductive deposit.

Claims

1. A conducting-composite comprising a partially densified silica aerogel structure and an electronically connected network of RuO₂ throughout the structure.

2. The composite of claim 1, wherein said silica aerogel is partially densified by heating said aerogel to about 900°

C.

3. A conducting composite produced by the following method:

providing a partially densified silica aerogel structure,

exposing the aerogel structure to a mixture of RuO₄ and a nonpolar solvent in an inert atmosphere, wherein the mixture is held initially at a first temperature that is below the ambient temperature and below the temperature at which RuO₄ decomposes into RuO₂ in the nonpolar solvent and in the presence of the aerogel, and

allowing the mixture to warm to a second temperature that is above the temperature at which RuO₄ decomposes to RuO₂ in the nonpolar solvent and in the presence of the aerogel, wherein the rate of warming is controlled so that as the mixture warms and the RuO₄ begins to decompose into RuO₂, the newly formed RiO₂ is deposited throughout the aerogel structure as an electronically connected deposit or network.

4. The composite of claim 3, wherein said silica aerogel is partially densified by heating said aerogel to about 900°

C.