Porous Materials

Abstract

A porous membrane material comprising a porous membrane substrate coated with a thin, uniform coating of a metal or metal alloy. The membrane material can have high electrical conductivity. The membrane material can exhibit a very high ratio of electrical conductivity to thermal conductivity. The porous membrane substrate may be removed to form the membrane.

Claims

1. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin and uniform coating of one or more metals or metal alloys, the coating having a thickness that falls in the range from ˜10 nm to ˜1 μm, wherein the coating extends all through the thickness of the porous material and wherein the coating imparts high conductivity to the membrane such that the porous material has an equivalent conductivity of from 0.05 S/cm to 440,000S/cm and wherein the porous material has a volume fraction of solid of less than 80%.

2. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin, uniform coating of one or more metals or metal alloys, the coating having a thickness that falls in the range from ˜10 nm to ˜1 μm, wherein the coating extends all through the thickness of the porous material and wherein the coating imparts high conductivity to the membrane such that the porous material has an equivalent conductivity of from 10 to 440,000S/cm and wherein the porous material has a volume fraction of coating of less than 80%.

3. A porous material as claimed in claim 1 wherein an equivalent conductivity of the porous material is at least ˜0.016% of that obtained for thin films of similar composition and thickness deposited on solid substrates.

4. A porous material as claimed in claim 1 wherein an equivalent conductivity of the porous material is 0.0065% or greater than that obtained for solid materials of similar composition, or ˜ 1/50.sup.th or greater than that obtained for solid materials of similar composition, or ˜ 1/20.sup.th or greater than that obtained for solid materials of similar composition, or ˜ 1/10.sup.th or greater than that obtained for solid materials of similar composition, or ˜⅕.sup.th or greater than that obtained for solid materials of similar composition, or ½ or greater than that obtained for solid materials of similar composition.

5. A porous material as claimed in claim 1 wherein an equivalent solid conductivity of the porous material ranges from about 10 S/cm to 281000 S/cm, or from10 S/cm to 1500 S/cm, or 100 S/cm to 1500 S/cm.

6. A porous material as claimed in claim 1 wherein the one or more metals or metal alloys is selected from the group consisting of copper, tin, nickel, iron, aluminum, titanium, cobalt, zinc, manganese, silver, gold, antimony, cadmium, tellurium, bismuth, platinum, palladium, ruthenium, rhodium, chromium, magnesium, calcium, beryllium, zirconium, molybdenum, lead, vanadium, potassium, niobium, cadmium, iridium, osmium, rhenium, indium, gallium, germanium, thallium, selenium and alloys thereof, and alloys comprising SnNi, SnFe, SnBi, SnSe, SnSb, SnSbNi, SnSbCo, CuSn, CuZn, Mg.sub.2Si, MnSn, MgSn, alloys based on the combination of titanium and aluminum.

7. A porous material as claimed in claim 1 wherein the material is post-treated to add additional functionality.

8. A porous material as claimed in claim 1 wherein the different material of the coating comprises nanoparticles such that the nanoparticles are applied to a surface of the substrate.

9. A porous material as claimed in claim 1 wherein the coating comprises nanolayers of the different material.

10. A porous material as claimed in claim 9 wherein the coating comprises a plurality of nanolayers.

11. A porous material as claimed in claim 1 wherein the porous material has a ratio of compressive strength (measured in Mpa) to volume fraction of solids (measured as volume fraction) of greater than 5 Mpa/v.sub.f, or greater than 10 MPa/v.sub.f, or greater than 50 MPa/v.sub.f, or greater than 100 MPa/v.sub.f.

12. A porous material as claimed in claim 1 wherein a thin layer of solid material is placed on top of the uniform coating, to provide a contacting surface.

13. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin, uniform coating of a one or more metals or metal alloys wherein the coating extends all through the thickness of the porous material and wherein the coating imparts high conductivity to the membrane and wherein the porous material has a volume fraction of solid of less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5% wherein the porous material has a ratio of compressive strength (measured in Mpa) to volume fraction of solids (measured as volume fraction) of greater than 5Mpa/v.sub.f, or greater than 10 MPa/v.sub.f, or greater than 50 MPa/v.sub.f, or greater than 100 MPa/v.sub.f.

14. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin, uniform coating of one or more metals or metal alloys wherein the coating extends all through the thickness of the porous material and wherein the coating imparts an equivalent solid conductivity in the range of 0.05 S/cm to 440,000 S/cm to the membrane and wherein the porous material has a volume fraction of solid of less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

15. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin, uniform coating of one or more metals or metal alloys wherein the coating extends all through the thickness of the porous material and wherein the coating imparts an equivalent solid conductivity in the range of 0.05 S/cm to 1500 S/cm to the membrane and wherein the porous material has a volume fraction of coating of less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

16. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin uniform coating of one or more metals or metal alloys, the coating having a thickness that falls within the range of from ˜10 nm to ˜200 nm wherein the coating extends all through the thickness of the porous material and wherein the coating imparts an equivalent solid conductivity in the range of 0.05 S/cm to 1500 S/cm to the membrane and wherein the porous material has a volume fraction of solid of less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

17. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin uniform coating of a different material, the coating having a thickness that falls within the range of from ˜10 nm to ˜200 nm wherein the coating extends all through the thickness of the porous material and wherein the coating imparts an equivalent solid conductivity in the range of 0.05 S/cm to 1500 S/cm to the membrane and wherein the porous material has a volume fraction of coating of less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

18. A porous material as claimed in claim 1 wherein the coating has a thickness that falls in the range of from ˜10 nm to ˜860 nm, or from ˜10 nm to ˜300 nm, or from ˜10 nm to ˜280 nm, or from ˜10 nm to -260 nm, or from ˜10 nm to ˜200 nm.

19. A porous material as claimed in claim 1 wherein the coating further comprises sulfur.

20. A porous material as claimed in claim 19 wherein the sulfur is present as a distinct layer.

21. A porous material as claimed in claim 19 wherein the sulfur is intimately mixed with one or more of the metals or metal alloys.

22. A porous material as claimed in claim 1 wherein the one or more metal alloys contain cobalt and one or more other metals.

23. A porous material as claimed in claim 1 wherein the volume fraction of solid is less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

24. A porous material as claimed in claim 2 wherein the volume fraction of solid is less than 50%, or less than 40%, or less than 30%, or less than 25% or less than 5.5%.

25. A porous material as claimed in claim 6 wherein the one or more metals or metal alloys are selected from copper, tin, nickel, iron, aluminium, titanium, cobalt, zinc, manganese, silver, gold, and alloys thereof.

26. A porous material comprising a porous polymeric membrane substrate having a pore size in a range from 0.1 μm to 10 μm and coated with a thin and uniform coating of one or more metal phosphides, the coating having a thickness that falls in the range from ˜10 nm to ˜1 μm, wherein the coating extends all through the thickness of the porous material and wherein the coating imparts high conductivity to the membrane such that the porous material has an equivalent conductivity of from 0.05 S/cm to 440,000 S/cm and wherein the porous material has a volume fraction of solid of less than 80%.

27. A porous material as claimed in claim 26 wherein the one or more metal phosphides are selected from one or more of copper phosphide, iron phosphide, tin phosphide, and nickel phosphide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

[0073] FIG. 1 shows a scanning electron micrograph of the porous material obtained in Example 1;

[0074] FIG. 2 shows a compositional analysis of the porous material obtained in Example 1;

[0075] FIGS. 3 and 4 show scanning electron micrographs of the porous material obtained in Example 2;

[0076] FIG. 5 shows a scanning electron micrograph of the porous material obtained in Example 4;

[0077] FIGS. 6 to 8 show scanning electron micrographs of the coated material obtained in Example 12;

[0078] FIGS. 9 and 10 show scanning electron micrographs of the porous material obtained in Example 13;

[0079] FIGS. 11 to 13 show scanning electron micrographs of the porous material obtained in Example 14;

[0080] FIGS. 14 to 16 show scanning electron micrographs of the coated material obtained in Example 15;

[0081] FIGS. 17 to 19 show scanning electron micrographs of the porous material obtained in Example 16;

[0082] FIGS. 20 and 21 shows scanning electron micrographs of the porous material obtained in Example 18;

[0083] FIG. 22 shows a scanning electron photomicrograph of the porous material obtained in Example 20; and

[0084] FIGS. 23 and 24 shows scanning electron photomicrographs of the porous material obtained in Example 22.

[0085] In order to better understand embodiments of the present invention, the following examples are provided.

EXAMPLES

Example 1

[0086] A porous polymeric substrate, with a non-woven fibrous composite structure, which contains cellulose fibers and has a thickness of 40 μm, was pretreated with an activator pre-treatment by contacting the substrate with a solution of 0.4 g/L PdCl.sub.2 and 10 g/L SnCl.sub.2 in 12M HCl at a temperature of 27.5° C. for 3 minutes. A copper coating was then applied to the substrate using electroless deposition. A Macdermid Copper 85 solution, which is a proprietary commercially available electroless copper depositions solution, was used. Electroless deposition of copper took place at 45.5° C. with a contact time of 30 minutes. A copper coating was formed on the substrate. FIG. 1 shows SEM photomicrographs of the coated material. The copper coating was seen to be uniformly applied to the substrate. FIG. 2 shows a compositional analysis of the material. The material was found to contain 90 atomic % copper.

Example 2

[0087] In this example, a substrate was coated with a mixed nickel/cobalt or a nickel/cobalt alloy. A porous polymeric substrate with a non-woven fibrous composite structure, which predominantly consists out of cellulose fibers 80 um thick, non-woven membrane reinforced through lamination to a Nylon scrim of 10-20 um thickness was pretreated with an activator comprising a solution of 0.4 g/L PdCl.sub.2 and 10 g/L SnCl.sub.2 in 12M HCl at a temperature of 27.5° C. for 3 minutes. A coating comprising nickel and cobalt was then applied by using a proprietary coating composition from Enthone that contains a Ni/Co ratio of 1:10. The substrate was contacted with this composition at 76° C. for 30 minutes, at a pH of 5.7. FIGS. 3 and 4 show SEM photomicrographs of the coated material. The nickel coating appeared to be uniformly applied to the substrate. The coating retained significant porosity.

Example 3

[0088] In this example, a substrate was coated with a nickel coating. A porous polymeric substrate with a non-woven fibrous composite structure with a thickness of 80 μm was pretreated lI at a temperature of 27.5° C. for 3 minutes. A nickel coating was then applied by using electroless deposition. The substrate was contacted with a nickel electroless solution containing Ni—18.13 g/L Nickel (II) chloride, 9.06 g/L sodium citrate, 32 g/L ammonium chloride and 18.06 g/L sodium hyposphosphite. The substrate was contacted with this composition at 67-72° C. for 90 minutes, at a pH of 9. The nickel coating extends throughout substantially all of the material. The coated material has the following composition:

TABLE-US-00001 TABLE 1 C O Na P Cl Fe Ni Cu A1 49.5 7.3 2.0 1.6 0.3 1.2 37.1 0.6 A2 30.1 8.3 3.8 2.2 0.7 1.2 51.9 0.8 A3 62.8 16.6 1.7 1.0 0.7 1.2 15.2 0.3 A4 42.3 11.4 3.3 1.6 0.9 1.3 38.0 0.5 A5 36.4 12.1 3.5 2.4 0.9 0.8 42.2 0.8 A5 56.0 8.1 2.0 1.0 0.2 0.6 30.5 0.8

Example 4

[0089] In this example, a coating comprising bismuth and tellurium was applied to a porous polymeric substrate. The substrate was a cellulose acetate (CA) membrane with a pore size of either 0.45 μm or 0.2 μm. The substrate was pretreated by immersing in a solution containing 1 mM PdCl.sub.2 at a pH of 5.50 for 10 to 15 minutes. The substrate was then contacted with an electroless nickel solution (a proprietary solution from Caswell) at a temperature of from 50 to 90° C. for 30 seconds. The substrate was subsequently contacted with a solution containing bismuth (III) chloride dissolved in 0.4 L 6wt % HCl, 5.2 g/L EDTA, 8.4 g/L Sodium hydroxide and Te-9.6 g/L Telluride powder, 6 g/L Sodium borohydride for a period of 3.5 hours. An outer coating comprising bismuth and telluride was formed. FIG. 5 shows an SEM photomicrograph of the coated porous material.

Examples 5 to 11

[0090] Examples 5 to 11 are set out in the table below. In examples 5 to 11, electroless deposition was used to form the final metal coatings on the porous polymeric substrate. A seed layer containing palladium chloride and tin chloride was first applied, followed by an optional accelerator step, followed by electroless deposition. Electrical conductivity of the porous material was determined. For some of the examples, the equivalent solid conductivity was also determined.

TABLE-US-00002 Equivalent solid Compositions used in Metal Conductivity conductivity Example Process Parameters process coatings Substrate (S/cm) (S/cm) 5 Electroless Activator— Sample pre-treatment: Copper Fibrous, 4506 91108 27.5° C., 3 min Activator—Macuplex non-woven, Accelerator— D34C with HCl 12M 20 μm 48.5° C., 1 min Accelerator— thickness Cu—46.5° C., Macuplex 9338 with 20 mins 12M HCl Copper coating: MacDermid Copper 85 6 Electroless Activator— Sample pre-treatment: Copper Fibrous, 18149 196547 27.5° C., 3 min Activator—Macuplex non-woven, Accelerator— D34C with HCl 12M 20 μm 48.5° C., 1 min Accelerator— thickness Cu—46.5° C., Macuplex 9338 with 60 mins 12M HCl Copper coating: MacDermid Copper 85 7 Electroless Activator— Sample pre-treatment: Copper Fibrous, 33832 280986 27.5° C., 3 min Activator—Macuplex non-woven, Accelerator— D34C with HCl 12M 20 μm 48.5° C., 1 min Accelerator— thickness Cu—46.5° C., Macuplex 9338 with 120 mins 12M HCl Copper coating: MacDermid Copper 85 8 Electroless Activator— Sample pre-treatment: Nickel Fibrous, 6497 98572 27.5° C., 3 min— Activator —Nickel non-woven, Ni—70-75° C., coating: 20 g/L Nickel 80 μm 40 mins, pH 9 (II) chloride, 10 g/L thickness Sodium citrate, 35 g/L Ammonium chloride, 0.1M Sodium hypophosphite 9 Electroless Activator— Sample pre-treatment: Nickel-Cobalt Fibrous, 1379 Not 27.5 C., 3 min, Activator—0.4 g/L alloy/co- non-woven, determined Ni—60° C., PdCl2 with 12M HCL, deposit 186 μm  30 mins, pH 8 10 g/L SnCl2 with 12M thickness HCL Nickel-cobalt coating: 38 g/L Nickel (II) chloride hexahydrate, 20 g/L Sodium citrate, 7.5 g/L Ammonium chloride, 0.9 g/L Cobalt (II) chloride, 2L DI H2O 10 Electroless Activator— Sample pre-treatment: Nickel-Cobalt Fibrous, 1976 Not 27.5 C., 3 min, Activator—0.4 g/L alloy/co- non-woven, determined Ni—75° C., PdCl2 with 12M HCL, deposit 55 μm 20 mins, pH 8 10 g/L SnCl2 with 12M thickness HCL Nickel-cobalt coating: 38 g/L Nickel (II) chloride hexahydrate, 20 g/L Sodium citrate, 7.5 g/L Ammonium chloride, 0.9 g/L Cobalt (II) chloride, 2L DI H2O 11 Electroless Activator— Sample pre-treatment: Copper, Fibrous, 9429 Not 27.5 C., 3 min Activator—Macuplex followed non-woven, determined Accelerator— D34C with HCl 12M by tin 65 μm 48.5 C., 1 min Accelerator— thickness Cu—30-40° C., Macuplex 9338 with 120 mins 12M HCl Copper Sn—29-30° C., coating: MacDermid 27 mins Copper 85 Tin coating: Sulfuric acid, 38.05 g/L Thiourea, 21.48 g/L Tin (II) sulfate, 53 g/L Sodium hypophosphite

Example 12

[0091] Substrate preparation: Cellulose acetate (CA) membranes with a pores size of 0.45 μm and a thickness of 127 μm and Polyethersulfone (PES) membranes with a pore size of 0.45 μm and a thickness of 100 μm were pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5), then coated using electroless deposition with either nickel or nickel followed by copper. Ni-28.3 g/L Nickel (II) sulfate, 42.03 g/L citric acid, 25 g/L sodium hydroxide, 3.3 g/L DMAB, Cu-15 g/L Copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L Sodium hydroxide, Formaldehyde—Zn Enthone CLZ-970 electrolytic plating solution. The electroless deposition was over a period of 10 minutes for nickel and three minutes for copper. The electrodeposition of zinc took place over a period of 40 minutes at 27° C. using a current of 100 mA. Metal coatings comprising nickel, copper and zinc were formed. FIGS. 6 to 8 are SEM photomicrographs showing the porous material produced in this example. Table 2 shows the composition of the coated material.

TABLE-US-00003 TABLE 2 C O S Ni Cu Zn A2 61.0 6.1 0.6 15.0 3.5 13.4 A3 36.1 6.9 1.6 16.9 14.3 24.2 A4 42.9 11.8 2.3 15.8 10.5 16.7 A5 60.2 14.2 2.7 6.5 5.6 10.8 A6 51.6 12.1 2.2 8.0 7.0 19.2

Example 13

[0092] In this example a polymeric membrane with a non-woven fibrous composite structure and a thickness of 115 μm was coated with nickel and iron using electroless deposition. The porous polymeric substrate was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). An electroless deposition solution comprising 0.08M Iron (II) sulfate hepahydrate, 28.3 g/L nickel (II) sulfate, 42.03 g/L citric acid, 25 g/L sodium hydroxide, 3.3 g/L DMAB was contacted with the substrate at 45° C. for a period of 12 minutes at pH 9. SEM photomicrographs are shown in FIGS. 9 and 10.

Example 14

[0093] A porous polymeric membrane such as a cellulose acetate (CA) membrane with a pore size of 0.45 μm and a thickness of 127 μm was coated using electroless deposition to form an outer coating containing gold. A combination of sensitization and activation steps was used to prepare the porous polymeric membrane for the electroless deposition of a layer of gold. The following conditions were used:

[0094] Pd—The membrane was immersed in an aqueous solution containing 1 mM PdCl2 at pH of 5 (pH was adjusted with NaOH). The membrane was soaked in the solution for 4h. Sn—The membrane was immersed in a solution that contained 0.026M tin (II) chloride, 0.07M trifluoracetic acid, 50%/50% methanol/water at room temperature for three minutes. Ag—The membrane was then transferred and immersed into an aqueous solution of ammoniacal silver nitrate (0.029M) at room temperature for two minutes. Au—1 ml/40 ml Oromerse part B, 0.127M sodium thiosulfate, 0.625M formaldehyde at room temperature, overnight. FIGS. 11, 12 and 13 show SEM photomicrographs of the porous material formed in this example. The composition of the various layers shown in FIG. 11 are set out in the table below (percentages given in atomic %). The gold coating extends throughout substantially all of the material. The coated material had the following composition:

TABLE-US-00004 TABLE 3 C O Pd Ag Sr Au A1 49.7 11.4 — 0 0.8 38.1 A2 34.6 1.5 0.8 1.26 — 61.9 A3 37.7 3.1 0.8 — — 57.7 A4 44.2 3.5 0.1 0.62 0.6 51.1 A5 46.3 11.4 0.4 0.53 0.2 41.4

Example 15

[0095] A porous Polyethersulfone (PES) substrate with a pore size of 0.45 μm was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). A layer of nickel was then deposited using electroless deposition. Sulphur was then deposited on the nickel using vapor phase deposition. The following conditions were used:

[0096] Ni—28.29 g/L nickel (II) sulfate, 42.03 g/L citric acid, 25 g/L sodium hydroxide, 3.6 g/L DMAB, at 45° C. for 60 minutes, pH 9. S—powder was placed in vapor deposition chamber under argon and not in contact with the nickel coated membrane. A temperature of 175° C. and a time of 180 minutes was used for the vapor phase deposition of sulfur. FIGS. 14 to 16 show SEM photomicrographs of the porous material obtained in this example. The composition of the regions marked in FIG. 20 are set out below (percentages given in atomic %):

TABLE-US-00005 TABLE 4 C O Si S Ni Cu Zn A1 25.3 27.2 0.0 12.5 33.2 1.4 0.5 A2 34.4 27.8 0.1 14.2 23.6 — — A3 39.8 39.2 0.1 8.4 12.4 — 0.2 A4 32.6 29.5 0.2 15.2 26.0 0.6 0.0 A5 45.1 22.0 0.5 16.2 15.8 0.5 —

Example 16

[0097] A porous polymeric membrane with a non-woven fibrous composite structure and a thickness of 115 μm was coated with copper and tin using electroless deposition. The substrate was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). The following conditions were used in the coating step:

[0098] Cu—15 g/L copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L sodium hydroxide, formaldehyde, for a period of 15 minutes. Sn—Sulfuric acid, 38.05 g/L thiourea, 21.48 g/L tin (II) sulfate, 53 g/L sodium hypophosphite, for a period of 10 minutes. FIGS. 17 to 19 show SEM photomicrographs of the porous material obtained in this example. The material had the following composition:

TABLE-US-00006 TABLE 5 C O Sn Cu Sn/Cu A1 59.7 2.1 21.8 16.2 1.3 A2 69.1 3.7 14.1 13.0 1.1 A3 64.1 2.1 14.3 19.3 0.7 A4 69.4 3.1 15.1 12.3 1.2 A5 65.2 7.9 19.0 7.7 2.5

Example 17

[0099] In this example, the porous polymeric membrane with a non-woven fibrous composite structure and a thickness of 115 μm was coated with nickel using electroless deposition followed by coating with iron and zinc using electrodeposition. The conditions used in the coating steps were as follows:

[0100] The substrate was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). Electroless coating of nickel and electroless coating of FeZn were completed under the following conditions:

[0101] Ni—28.29 g/L nickel (II) sulfate, 42.03 g/L citric acid,25 g/L sodium hydroxide, 0.12M sodium hypophosphite, for a period of 15 minutes at 65° C. and pH 8. FeZn—0.05M Ferrous glucanate dihydrate, 0.15M zinc oxide, 6.6M potassium hydroxide at room temperature and the current of 0.96 A.

Example 18

[0102] In this example, a porous polymeric cellulose acetate (CA) substrate with a pore size of 0.45 μm and a thickness of 127 μm was coated with a coating of copper and then a coating of tin using electrodeposition. The substrate was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). Electrodeposition was then used to sequentially apply copper and then tin. The following conditions were used in the electroless and electrodeposition steps:

[0103] Cu—15 g/L Copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L sodium hydroxide, formaldehyde, 30° C., 4.5 minutes, 30mA current. Sn—15 g/L Tin methanesulphonate, 100 g/L gluconic acid sodium salt, 0.8 g/L triton X, 0.1 g/L 2 bipyridyl, room temperature, 104 minutes, 30mA current. FIGS. 20 and 21 show SEM photomicrographs of the porous material must obtained. The composition of the layers shown in FIG. 20 is as follows (percentages given in atomic %):

TABLE-US-00007 TABLE 6 C O Al Cu Sn A1 27.7 12.8 0.4 49.0 10.2 A2 37.5 15.9 — 44.7 1.8 A3 52.4 26.4 — 20.4 0.8 A4 48.2 22.2 — 27.6 1.0 A5 36.4 16.6 — 44.7 2.4

Example 19

[0104] A porous polymeric cellulose acetate (CA) substrate with a pore size of 0.45 μm and a thickness of 127 μm was used in this example. The substrate was pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5). A thin nickel coating layer was applied using electroless deposition prior to the electrodeposition step. The electrodeposition step used a solution containing Ni—250 g/L Nickel (II) sulfate hexahydrate, 50 g/L nickel (II) chloride, 35 g/L boric acid. The temperature during electrodeposition was 45 to 47° C. Electrodeposition occurred over a period of 120 minutes using a current of 50 mA. A substantially uniform coating of nickel was obtained.

Example 20

[0105] In this example, an electroless copper coating was applied to a porous polymeric, non-woven substrate consisting out of polyethylene terephthalate fibers (PET). The thickness of the substrate was 15 μm. The substrate was pretreated with an activator comprising Macuplex D34C with 12M HCl. Macuplex D34C is a proprietary commercially available activator that contains palladium chloride and tin chloride. The activation step took place at 27.5° C. for a period of three minutes. The substrate was then contacted with an accelerator comprising Macuplex 9338 with 12M HCl. Contact between the accelerator and the substrate took place at 48.5° C. for a period of one minute. A copper layer was then applied by contacting the substrate with MacDermid Copper 85 at a temperature of 46.5° C. for a period of 120 minutes. FIG. 22 shows an SEM photomicrograph of the coated porous material. The coating was evenly applied. Significant porosity was retained.

Example 21

[0106] A porous polymeric membrane with a non-woven fibrous composite structure and which has a thickness of 115 μm was coated with copper and a tin-nickel alloy using electroless deposition. The following conditions were used in the coating step:

[0107] Cu—15 g/L Copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L sodium hydroxide, formaldehyde, for a period of 15 minutes. SnNi—Tin(II) chloride dehydrate 20 g/L, nickel(II) chloride hexahydrate 20 g/L, sodium hypophosphite 60 g/L, thiourea 60 g/L, citric acid monohydrate 20 g/L, tartaric acid dehydrate 40 g/L, hydrochloric acid 70 g/L for a period of 20 min at temperature between 60-75° C. The material had the following composition (percentages given in atomic %):

TABLE-US-00008 TABLE 7 C O Sn Ni Cu Sn/Ni Ni/Cu A1 60.8 5.4 9.4 7.1 16.8 1.3 0.4 A2 59.4 10.5 10.6 7.2 11.6 1.5 0.6 A3 66.4 8.8 8.5 6.4 9.6 1.3 0.7 A4 76.0 12.1 4.4 3.5 3.8 1.3 0.9 A5 71.5 10.9 7.1 5.1 5.3 1.4 1.0

Example 22

[0108] A porous polymeric membrane with a composite structure comprising a polyethylene and ethyl vinyl alcohol, which has a pore size of 1.5 μm and a thickness of 60 μm was coated with copper using electroless deposition. The following conditions were used in the coating step:

[0109] Cu—15 g/L Copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L sodium hydroxide, formaldehyde, for a period of 19 minutes at 30° C. FIGS. 23 and 24 show SEM photomicrographs of the porous material obtained in this example. Compositional analysis at various regions of the porous material are shown in Table 8, which shows that the copper extends throughout the thickness of the material.

TABLE-US-00009 TABLE 8 C O Cu A1 33.0 0.8 65.5 A2 60.2 1.1 38.3 A3 58.5 1.3 39.5 A4 65.6 1.5 32.3 A5 54.6 2.2 42.6

Example 23

[0110] A porous polymeric nylon substrate, was coated with copper using electroless deposition. The following conditions were used in the coating step:

[0111] Cu—15 g/L Copper (II) sulfate pentahydrate, 27 g/L EDTA, 8.75 g/L sodium hydroxide, formaldehyde, for a period of 30 minutes at 30° C. The substrate could be pre-treated to accept electroless deposition (such as by using the pre-treatment steps of examples 1 to 5).

Example 24

[0112] In this example, the porous polymeric membrane was a non-woven fibrous composite structure and a thickness of 115 μm. The substrate was first coated with a conductive layer by using electroless deposition to apply a layer of nickel. Electro-precipitation was then used to sequentially apply a nickel-cobalt-zinc alloy. The following conditions were used in the deposition steps:

[0113] Ni—A commercial nickel chemistry from Technic was used for the electroless deposition of the first nickel layer. The deposition was carried out for 45 minutes at 50° C.

[0114] NiCoZn—1.5M Nickel nitrate hexahydrate, 0.14M cobalt (II) chloride hexahydrate, 0.07M zinc (II) nitrate hexahydrate, room temperature, 5 h, 100 mA current.