Hybrid Organic-Inorganic Materials and Methods of Preparing the Same
Embodiments of the present invention describe hybrid organic-inorganic aerogel materials wherein a variety of organic components are incorporated into the aerogel. Methods provided herein allow functionalization and or reinforcement of aerogels starting with urea or urethane formation reactions, gelation with inorganic precursors and subsequent drying thereof.
1 . A method of incorporating at least one organic component into a porous silica material comprising the steps of:
a) reacting a first organoalkoxysilane comprising at least one isocyanate group with a second organoalkoxysilane comprising at least one reactive amine group, such that a urea group is formed linking both said first and second organoalkoxysilane and resulting in a urea bridged compound; further wherein said first, second or both organoalkoxysilanes comprise at least one organic component other than a urea or amine;
b) reacting the urea bridged compound with a silica precursor thereby forming a gel network with said organic component covalently bonded therein; and
c) drying said gel thereby obtaining an aerogel material.
2 . The method of claim 1 wherein the gel is dried with a supercritical fluid.
3 . The method of claim 1 where said silica precursor is an alkylalkoxysilane, ethylpolysilicate, tetraethylorthosilicate (TEOS), tetramethylorthosilicate (TMOS), partially hydrolyzed TEOS, partially hydrolyzed TMOS or a combination thereof.
4 . The method of claim 1 wherein the organoalkoxysilanes are organotrialkoxysilanes
5 . The method of claim 4 wherein said organotrialkoxysilanes are organotriethoxysilanes.
6 . The method of claim 1 wherein the urea bridged compound is tolylene 2,4 di-ureapropyltriethoxysilane, 4,4 methylene bis(phenylureapropyltriethoxysilane), 1,6-di(triethoxypropylrea)-hexane, isophorone-di(triethoxypropylurea) or tolylene 2,4 di-(triethoxysilylpropylurea).
7 . The method of claim 1 comprising an olefinic compound, aliphatic compound, arylenic compound, acetylenic compound, organometallic compound, coordination compound, or a combination thereof.
8 . The method of claim 1 further comprising the step of combining the product of step a) with a fibrous structure.
9 . The method of claim 8 wherein the fibrous structure comprises microfibers, mats, felts, woven fabrics, non-woven fabrics, fibrous battings, lofty battings or a combination thereof.
10 . The method of claim 1 comprising the step of incorporating additives in the gel before drying thereof.
11 . The method of claim 10 wherein the additives comprise organic or inorganic fillers, antioxidants, fibers, infrared opacifiers, flame retardants, smoke suppressants, oxidation catalysts or combinations thereof.
12 . The method of claim 11 wherein the opacifiers comprise: B 4 C, Diatomite, Manganese ferrite, MnO, NiO, SnO, Ag 2 O, Bi 2 O 3 , TiC, WC, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron (I) oxide, iron (III) oxide, manganese dioxide, iron titanium oxide, chromium oxide, silicon carbide and any combination thereof.
13 . The method of claim 1 wherein the aerogel material comprises greater than 10% of the urea bridged compound by weight.
14 . The method of claim 1 wherein the aerogel material comprises greater than 40% of the urea bridged compound by weight.
15 . The method of claim 1 wherein the aerogel material has a thermal conductivity of less than about 15 mW/m·K at room temperature and ambient pressure.
16 . The method of claim 1 wherein the aerogel material has a flexural modulus greater than about 480 psi.
17 . The method of claim 1 wherein the aerogel material has a density less than about 0.1 g/cm 3 .
18 . (canceled)
19 . (canceled)
20 . An aerogel material manufactured according to claims 1 .
21 . A method of incorporating at least one organic component into a porous silica material comprising the steps of:
a) reacting a first organoalkoxysilane comprising at least one isocyanate group with a second organoalkoxysilane comprising at least one reactive hydroxyl group, such that a urethane group is formed linking both said first and second organoalkoxysilane and resulting in a urethane bridged compound; further wherein said first, second or both organoalkoxysilanes comprise at least one organic component other than a hydroxyl or amine;
b) reacting the urethane bridged compound with a silica precursor thereby forming a gel network with said organic component covalently bonded therein; and
c) drying said gel thereby obtaining an aerogel material.
22 . The method of claim 21 wherein the gel is dried with a supercritical fluid.
23 . The method of claim 21 where said silica precursor is an alkylalkoxysilane, ethylpolysilicate, tetraethylorthosilicate (TEOS), tetramethylorthosilicate (TMOS), partially hydrolyzed TEOS, partially hydrolyzed TMOS or a combination thereof.
24 . The method of claim 21 wherein the organoalkoxysilanes are organotrialkoxysilanes
25 . The method of claim 21 wherein said organotrialkoxysilanes are organotriethoxysilanes.
26 . The method of claim 21 comprising an olefinic compound, aliphatic compound, arylenic compound, acetylenic compound, organometallic comopund, coordination compound, or a combination thereof
27 . The method of claim 21 further comprising the step of combining the product of step a) with a fibrous structure.
28 . The method of claim 21 wherein the fibrous structure is microfibers, mats, felts, woven fabrics, non-woven fabrics, fibrous battings, lofty battings or a combination thereof.
29 . The method of claim 21 further comprising the step of incorporating additives in the gel before drying thereof.
30 . The method of claim 29 wherein the additives comprise organic or inorganic fillers, antioxidants, fibers, infrared opacifiers, flame retardants, smoke suppressants, oxidation catalysts or combinations thereof.
31 . The method of claim 30 wherein the opacifiers comprise: B 4 C, Diatomite, Manganese ferrite, MnO, NiO, SnO, Ag 2 O, Bi 2 O 3 , TiC, WC, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron (I) oxide, iron (III) oxide, manganese dioxide, iron titanium oxide, chromium oxide, silicon carbide and any combination thereof.
32 . The method of claim 21 wherein the aerogel material comprises greater than 10% of the urea bridged compound by weight.
33 . The method of claim 21 wherein the aerogel material comprises greater than 40% of the urea bridged compound by weight.
34 . The method of claim 21 wherein the aerogel material has a thermal conductivity of less than about 15 mW/m·K at room temperature and ambient pressure.
35 . The method of claim 21 wherein the aerogel material has a flexural modulus greater than about 480 psi.
36 . The method of claim 21 wherein the aerogel material has a density less than about 0.2 g/cm 3 .
37 . (canceled)
38 . (canceled)
39 . An aerogel material manufactured according to claims 21 .