Layered silicate material and applications of layered materials with porous layers
Layered silicate materials and applications are disclosed. In one aspect, the invention features layered silicate materials having pores that run generally perpendicular to the layers. In another aspect, the invention features composite materials including layered framework materials (e.g., layered silicate materials, layered Aluminophosphate materials, layered tin sulfides) having pores or openings that run generally perpendicular to the layers.
1. A layered silicate material comprising:
a first layer including a plurality of tetrahedral SiO 4 units, the first layer having a first plurality of channels extending from a top side of the first layer to a bottom side of the first layer, wherein each channel in the first plurality of channels is defined by an X-membered ring where X is an integer and is the same for each channel;
the first layer further including a second plurality of channels extending essentially parallel to the top side of the first layer.
2. The layered silicate material of claim 1 , wherein X is 8.
3. The layered silicate material of claim 1 , wherein X is 12.
4. The layered silicate material of claim 1 , wherein the channels in the first plurality of channels have diameters in a range of about 3–6 Angstroms.
5. The layered silicate material of claim 1 , wherein the top side is approximately parallel to the bottom side.
6. The layered silicate material of claim 1 , further comprising a second layer comprising a plurality of SiO 4 units and having a plurality of channels extending from a first side of the second layer to a second side of the second layer.
7. The layered silicate material of claim 6 , wherein the bottom side of the first layer is approximately parallel to the top side of the second layer.
8. The layered silicate material of claim 6 , wherein the first plurality of channels in the first layer are registered with the channels in the second layer.
9. The layered silicate material of claim 6 , further comprising a plurality of cations located between the bottom side of the first layer and top side of the second layer.
10. The layered silicate material of claim 9 , wherein the cations comprise sodium ions or strontium ions.
11. The layered silicate material of claim 1 , wherein the first layer is no more than about 50 Angstroms thick.
12. The layered silicate material of claim 1 , further comprising a third plurality of channels extending essentially parallel to the top side of the first layer and essentially perpendicular to the second plurality of channels.
13. The layered silicate material of claim 1 , further comprising another element substituted for a portion of the Si atoms in the material.
14. The layered silicate material of claim 13 , wherein the element provides acid catalytic sites within the layer.
15. The layered silicate material of claim 13 , wherein the element provides base catalytic sites within the layer.
16. The layered silicate material of claim 13 , wherein the element is Al, B, Ge, Ce, or Ti.
17. A composite material, comprising a continuous phase and a dispersed phase, wherein the continuous phase comprises a polymer and the dispersed phase comprises the layered silicate material of claim 1 .
18. The composite material of claim 17 , wherein the polymer is selected from the group of nylon, polyolefin, polystyrene, ethylene-vinyl acetate copolymer, polyurethane, polyimide and poly(ethylene terephthalate).
19. A porous membrane comprising the composite material of claim 17 .
20. The layered silicate material of claim 1 , wherein each channel in the first plurality of channels has a minimum diameter of more than about 3 Angstroms and a maximum diameter of less than about 20 Angstroms.
21. A layered silicate material comprising a first layer including a plurality of tetrahedral SiO 4 units, the first layer having a plurality of channels extending from a top side of the first layer to a bottom side of the first layer, wherein each channel is defined by an X-membered ring where X is an integer and is the same for each channel, and wherein the channels have diameters in a range of about 3–6 Angstroms.