Microwave-attenuating composite materials, methods for preparing the same, intermediates for preparing the same, devices containing the same, methods of preparing such a device, and methods of attenuating microwaves
View Patent ↗The present invention provides microwave attenuating, filled composite materials which contain a polymer or ceramic matrix and metallic tubules and processes for making the same and devices which contain such materials.
1. A process for producing a metallic lipid microtubule comprising,
(a) suspending a lipid in an alcohol-water solvent, to form lipid microtubules;
(b) adding a polyanion mixture, to obtain a lipid microtubule-polyanion mixture;
(c) incubating said lipid microtubule-polyanion mixture, to obtain an incubated lipid microtubule-polyanion mixture;
(d) adding a polycation mixture to said incubated lipid microtubule-polyanion mixture, to obtain a polycation-lipid microtubule-polyanion mixture;
(e) adding a palladium catalyst to said polycation-lipid microtubule-polyanion mixture, to obtain a catalyst mixture, wherein said palladium catalyst is selected from the group consisting of PD1A and PD1B;
(f) incubating said catalyst mixture for a minimum of 30 minutes; and
(g) electroless coating the lipid microtubules.
2. The process according to claim 1 , wherein said lipid is suspended at a concentration of 2.5 mg/ml.
3. The process according to claim 1 , wherein said alcohol-water solvent comprises 70 wt. % of an alcohol mixture and 30 wt. % distilled water.
4. The process according to claim 3 , wherein said alcohol mixture comprises 20 to 80 wt. % methanol and 20 to 80 wt. % ethanol.
5. The process according to claim 1 , wherein said polyanion mixture has a concentration ranging from 0.1 to 1.0 mg/ml.
6. The process according to claim 1 , wherein said polyanion mixture comprises polystyrenesulfonate.
7. The process according to claim 1 , wherein said incubating said lipid microtubule-polyanion mixture is carried out for 15 to 45 minutes.
8. The process according to claim 1 , wherein said polycation mixture has a concentration ranging from 0.5 to 1.5 mg/ml.
9. The process according to claim 1 , wherein said polycation mixture comprises polyethyleneimine or chitosan.
10. The process according to claim 1 , wherein the said incubating results in the formation of a cross-linked polycation layer on the surface of said lipid microtubules.
11. The process according to claim 1 , wherein said PD1A is added in the form of a solution or dispersion which comprises 3.5 to 3.75 mM [Pd(II)], 120 to 130 mM [Cl − ], and 15 to 20 mM [MES] at a pH of 5.
12. The process according to claim 11 , wherein said solution or dispersion comprises about 3.67 mM [Pd(II)], about 127 mM [Cl − ], and about 18 mM [MES] at a pH of 5.
13. The process according to claim 1 , wherein said PD1B is added in the form of a solution or dispersion which comprises 3.5 to 3.75 mM [Pd(II)], 115 to 120 mM [Cl − ], and 15 to 20 mM [MES] at a pH of 5.
14. The process according to claim 13 , wherein said solution or dispersion comprises about 3.67 mM [Pd(II)], about 118 mM [Cl − ], and about 18 mM [MES] at a pH of 5.
15. The process according to claim 1 , wherein said palladium catalyst is added in the form of a solution or dispersion at a volume ratio of 1:500 of said solution or dispersion to said polycation-lipid microtubule-polyanion mixture.
16. The process according to claim 1 , wherein said electroless coating comprises adding a formulation comprising a metal selected from the group consisting of copper, nickel, cobalt, iron, and a permalloy metal.