Metal-coated lipid bilayer vesicles and process for producing same

1. A hollow metal-coated material comprising:

a lipid bilayer vesicle having a network of siloxane bonding (Si—O—Si bonding) on its surface, wherein a functional group having the ability of carrying a metal catalyst is rendered to the surface of the lipid bilayer vesicle, said functional group being selected from the group consisting of carboxyl, sulfonic, mercapto, phosphoric, phosphonic, dithiocarbamic, amino, imino, azole, ether, and ketone groups, and combinations thereof, whereby the metal catalyst is immobilized on the surface of the lipid bilayer vesicle, and

a metal coating on the lipid bilayer vesicle having said siloxane bonding network.

2. The metal-coated material according to claim 1 , wherein the metal catalyst contains one or more metals selected from the group consisting of palladium, silver, platinum, gold, rhodium and iridium,

3. The metal-coated material according to claim 1 , wherein the metal coating contains one or more metals selected from the group consisting of nickel, cobalt, iron, tin, palladium, copper, silver, gold, platinum, lead, rhodium and ruthenium.

4. The metal-coated material according to claim 1 , in the form of powder.

5. The metal-coated material according to claim 1 , wherein it is provided in the form of a water dispersion.

6. The metal-coated material according to claim 4 or 5 , having a cumulant average particle diameter from 30 nm to 10 μm.

7. A preparation method for preparing the metal-coated material according to claim 1 , comprising the following steps:

(1) rendering a functional group having the ability of carrying a metal catalyst to the surface of a lipid bilayer vesicle having a network of siloxane bonding (Si—O—Si bonding) on its surface, at or after the formation, by self-organization, of the lipid bilayer vesicle, said functional group being selected from the group consisting of carboxyl, sulfonic, mercapto, phosphoric, phosphonic, dithiocarbamic, amino, imino, azole, ether, and ketone groups, and combinations thereof;

(2) immobilizing a metal catalyst on the surface of the lipid bilayer vesicle;

(3) optionally, reducing the metal catalyst; and

(4) performing electroless plating;

wherein steps (1) to (4) are performed under a temperature environment where the lipid bilayer vesicle maintains a gel state.

8. The preparation method according to claim 7 , wherein step (2) comprises contacting the lipid bilayer vesicle with an aqueous solution containing chloride, hydroxide, oxide, sulfate and/or ammmne complex of one or more precious metals selected from the group consisting of palladium, silver, platinum, gold, rhodium and iridium.

9. The preparation method according to claim 7 , wherein step (3) is performed and comprises contacting the lipid bilayer vesicle on the surface of which the metal catalyst has been immobilized with H 3 PO 2 (hypophosphorous acid), NaH 2 PO 2 (sodium hypophosphite), dimethylamine borane (DMAB), NaBH 4 , KBH 4 , NH 2 NH 2 , HCHO, SnCl 2 , CH 4 NH 2 S, or a mixture thereof.

10. The preparation method according to claim 7 , wherein step (1) includes, at the formation of the lipid bilayer vesicle, introducing an amphiphatic organic compound capable of forming a bilayer by self-organization bearing the functional group having the ability of carrying a metal catalyst, or introducing an alkoxysilane bearing the functional group having the ability of carrying metal catalyst.

11. The preparation method according to claim 7 , wherein step (1) includes, after the formation of the lipid bilayer vesicle, treating the surface of the lipid bilayer vesicle with a silane coupling agent bearing the functional group having the ability of carrying a metal catalyst.

12. An article comprising a base on which a hollow lipid bilayer vesicle having a network of siloxane bonding (Si—O—Si bonding) on its surface is immobilized, wherein a functional group having the ability of carrying a metal catalyst is rendered to the surface of the lipid bilayer vesicle, said functional group being selected from the group consisting of carboxyl, sulfonic, mercapto, phosphoric, phosphonic, dithiocarbamic, amino, imino, azole, ether, and ketone groups, and combinations thereof,

whereby the metal catalyst is immobilized on the surface of the lipid bilayer vesicle, and the lipid bilayer vesicle having said siloxane bonding network is coated with metal.

13. The article according to claim 12 , wherein the metal catalyst contains one or more metals selected from the group consisting of palladium, silver, platinum, gold, rhodium and iridium.

14. The article according to claim 12 , wherein the coating metal contains one or more metals selected from the group consisting of nickel, cobalt, iron, tin, palladium, copper, silver, gold. platinum, lead, rhodium and ruthenium.

15. The article according to claim 12 , wherein the surface material of the base on which the lipid bilayer vesicle is immobilized is selected from the group consisting of glass, mica, quartz, epoxy-resin, polyimide-resin, PET and liquid crystal polymer.

16. The article according to claim 12 , wherein the base is selectively metal-coated at the place where the lipid bilayer vesicle is immobilized.

17. The article according to claim 16 , wherein the metal on the base forms a circuit.

18. A preparation method for preparing the article according to claim 12 , comprising the following steps:

(a) immobilizing on a base a lipid bilayer vesicle having a network of siloxane bonding (Si—O—Si bonding) on its surface by an alternating lamination using an electrostatic interaction;

(b) rendering a functional group having the ability of carrying a metal catalyst to the surface of the lipid bilayer vesicle, said functional group being selected from the group consisting of carboxyl, sulfonic, mercapto, phosphoric, phosphonic, dithiocarbamic, amino, imino, azole, ether, and ketone groups, and combinations thereof;

(c) immobilizing the metal catalyst on the surface of the lipid bilayer vesicle; wherein the steps (a), (b) and (c) are performed in the following sequence;

(a)→(b)→(c), (b)→(c)→(a), or (b)→(a)→(c), and subsequently

(d) optionally, reducing the metal catalyst; and

(e) performing electroless plating;

wherein steps (1) to (4) are performed under a temperature environment where the lipid bilayer vesicle maintains a gel state.

19. The preparation method according to claim 18 , wherein the steps (a), (b) and (c) are performed in the sequence (b)→(c)→(a), or (b)→(a)→(c), and the step (b) comprises, at the formation of the lipid bilayer vesicle, introducing an amphiphatic organic compound capable of forming a bilayer by self-organization bearing the functional group having the ability of carrying a metal catalyst, or introducing an alkoxysilane bearing the functional group having the ability of carrying a metal catalyst.

20. The preparation method according to claim 18 , wherein the step (c) comprises contacting the lipid bilayer vesicle with an aqueous solution containing chloride, hydroxide, oxide, sulfate and/or ammine complex of one or more precious metals selected from the group consisting of palladium, silver, platinum, gold, rhodium and iridium.

21. The preparation method according to claim 18 , wherein the step (d) is performed and comprises contacting the lipid bilayer vesicle on the surface of which the metal catalyst has been immobilized, with H 3 PO 2 (hypophosphorous acid), NaH 2 PO 2 (sodium hypophosphite), dimethylamine borane (DMAB), NaBH 4 , KBH 4 , NH 2 NH 2 , HCHO, SnCl 2 , CH 4 NH 2 S, or a mixture thereof.

22. The preparation method according to claim 18 , wherein the step (b) comprises, after the formation of the lipid bilayer vesicle, treating the surface of the lipid bilayer vesicle with a silane coupling agent hearing the functional group having the ability of carrying a metal catalyst.