Surface functionalisation method

Abstract

The invention relates to a method for functionalising a surface of a solid substrate with at least one acrylic acid polymer layer, said method including the steps of: i) placing the surface in contact with a solution having of at least one acrylic acid homopolymer, a solvent and, optionally, metal salts; ii) removing the solvent from the solution in contact with the surface; and iii) binding the polymer to the surface by thermal treatment.

Claims

1. A process for functionalizing a surface of a solid support with at least one layer of polymer of acrylic acid, said process comprising the stages of: i) bringing said surface into contact with a solution consisting of: at least one acrylic acid homopolymer; and a solvent; ii) removing the solvent from the solution in contact with said surface; and iii) fixing the polymer to said surface by heat treatment at a temperature of between 150° C. and 300° C.; the solid support being selected from the group consisting of metal oxides, papers, and carbon fibers.

2. The process as claimed in claim 1, in which the polymer is applied to the surface of the solid support by dipping, centrifuging, sprinkling, projection or transfer.

3. The process as claimed in claim 1, in which the process additionally comprises stages ii.sub.1) and ii.sub.2), subsequent to stage ii) of: ii.sub.1) rinsing the surface of the solid support obtained in stage ii) with water; and ii.sub.2) drying said surface.

4. The process as claimed in claim 1, comprising a stage, subsequent to stage iii), of covalent grafting of at least one molecule to the polymer layer obtained.

5. The process as claimed in claim 4, in which the at least one molecule is a biological molecule or a resin.

6. The process as claimed in claim 4, in which the at least one molecule consists of two molecules as a two-component resin.

7. The process as claimed in claim 1, wherein the support comprises metal oxides.

8. The process as claimed in claim 1, wherein the support is selected from the group consisting of papers and carbon fibers.

9. The process as claimed in claim 1, wherein the support comprises papers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1:

(2) 1-a) Photograph of a glass strip partially immersed (right-hand part (3×1 cm)) in a palladium activation bath and then in a nickel metallization bath in the presence of a PAA layer.

(3) 1-b) Enlargement of a portion of the metalized glass strip showing residues of bonding substance from the adhesive tape used to test the adhesion of the metal layer. Illustration of the good adhesion of the metal to the glass.

(4) 1-c) and 1-d) Photographs of two glass strips partially immersed in a palladium activation bath and then in a nickel metallization bath in the absence of a PAA layer. The test with the adhesive tape this time shows a very easy detachment of the metal layer at several locations.

(5) 1-e) Photograph of a glass strip partially immersed in a palladium activation bath and then in a nickel metallization bath in the presence of a residual and conforming PAA film with a thickness of a few nanometers. The heat treatment of the thin PAA film is carried out with a heat gun.

(6) FIG. 2:

(7) Photograph of a glass strip immersed in a palladium activation bath and then in a nickel metallization bath in the presence of a PAA film locally deposited on the surface using an adhesive stencil. The metallization took place only at the locations where PAA was deposited.

(8) FIG. 3:

(9) 3(a) and 3(b): Photographs of a PVC surface partially immersed in a palladium activation bath and then in a nickel metallization bath in the presence of a PAA layer (a) and in the absence of a PAA layer (b).

(10) 3(c): Photograph of a PTFE surface which has been degreased and then partially immersed in a palladium activation bath and then in a nickel metallization bath in the absence of a PAA layer. No metallization detectable.

(11) 3(d): Photograph of a PTFE surface which has been immersed in a PAA solution and then partially immersed in a palladium activation bath and then in a nickel metallization bath. No metallization detectable.

(12) 3(e): Photograph of a PTFE surface pretreated by argon plasma, thus rendering it wetting with regard to a PAA solution in which it is immersed, then partially immersed in a palladium activation bath and then in a nickel metallization bath.

(13) FIG. 4:

(14) Photograph of a PVC surface locally metalized by using the PAA solution as an ink deposited by a fountain pen.

(15) FIG. 5:

(16) IR transmittance as a function of the wavelength of a polyimide (PI) support functionalized by PAA.

(17) FIG. 6:

(18) IR transmittance as a function of the wavelength of a PolyEthylene Terephthalate (PET) support functionalized by PAA A) PET B) PET+PAA before VUV irradiation C) PET+PAA+VUV copiously rinsed with water, irradiated side D) PET+PAA+VUV copiously rinsed with water, nonirradiated side.

(19) FIG. 7:

(20) IR transmittance as a function of the wavelength of a PolyEthylene (PE) support functionalized by PAA A) PE B) PE+PAA before VUV irradiation C) PE+PAA+VUV copiously rinsed with water, irradiated side D) PE+PAA+VUV copiously rinsed with water, nonirradiated side.

(21) FIG. 8:

(22) Immobilization and structuring by VUV irradiation of a thin PAA film on a gilded glass strip. Top: visible image. Bottom left: profilometric measurement carried out on the black line of the image. Bottom right: IR spectrum outside and inside the irradiated region.

(23) FIG. 9:

(24) (a) chemical mechanism responsible for the adhesion of the amine hardener of the resin to the anhydride groups of the support.

(25) (b): results of the standardized adhesion tests in the absence (top) and in the presence (bottom) of the anhydride layer.

(26) (c): representation of the surface of the substrate after the adhesion tests in the absence (top) and in the presence (bottom) of the anhydride layer (red line).

(27) FIG. 10:

(28) Increase in the surface energy of the hydrophobic PVC. Measurement of the contact angles before (left—70°) and after (right—30°) treatment.

(29) FIG. 11:

(30) Decrease in the surface energy of a gilded surface. Hydrophilic gold layer became hydrophobic by grafting a long alkyl layer. Top: IR transmittance as a function of the wavelength of a gilded support (gold layer evaporated onto glass) functionalized by PAA and grafted by a Cu alkyl amine. Bottom: Measurement of the contact angles. (Left) Gold alone, (center) Gold+PAA, (right) Gold+PAA+C.sub.11 amine.

(31) FIG. 12:

(32) IR transmittance as a function of the wavelength of a support made of gold functionalized by an adsorbed residual layer of PAA.

(33) FIG. 13:

(34) IR transmittance as a function of the wavelength relating the different stages of grafting of proteins with activation of the surface in an organic medium. a) Spectrum of PAA grafted to a gilded support and modified at the surface via the formation of functional groups of activated ester (COOSu) type b) Spectrum of PAA grafted to a gilded support, after coupling of the functional groups of activated ester (COOSu) type with a protein. The spectrum of the protein alone is superimposed.

(35) FIG. 14:

(36) IR transmittance as a function of the wavelength relating the different stages of grafting of proteins with activation of the surface in an aqueous medium. a) Spectrum of the functionalized PAA support after NHS/EDC activation in an aqueous medium: formation of the anhydride functional groups by the chemical route. b) Spectrum of the support activated as anhydride functional groups after coupling of these functional groups with a protein. c) Spectrum of the PAA-functionalized support after NHS/EDC activation in an aqueous medium, having been immersed in DI water at a pH equal to 6 for 15 minutes: persistence of the anhydride functional groups.

(37) FIG. 15:

(38) Photographs a) of the fibers of the virgin carbon felt before coating and b) and c) of the fibers of the carbon felt coated with the PAA film.

(39) FIG. 16:

(40) Treated carbon felts and column treatment device.

(41) FIG. 17:

(42) Metallization of a sheet of carbon-epoxy composite used in the aeronautical industry.

(43) FIG. 18:

(44) Energy of different chemical bonds as a function of the wavelength.

(45) The following examples illustrate the invention without, however, limiting it.

DETAILED DESCRIPTION

Examples

Example 1: Metallization of the Surfaces

Example 1-a/: Full Surface Metallization of a Glass Surface. (Heat Treatment)

(46) i) Coating and Immobilization of the Coating of Acrylic Acid Polymer (PAA).

(47) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(48) A glass strip of microscope slide type (7.5×2.5 cm) is degreased (washing with a surfactant typically followed by an alcohol rinsing) and then dried (with a dry nitrogen gas blower and then by placing in an oven at 100° C. for 15 min).

(49) For a metallization of full surface type, the PAA solution is applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness of 50 to 70 nm. The deposition of PAA takes place then on both sides of the glass strip (FIG. 1).

(50) The glass strips coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(51) ii) Activation

(52) Preparation of the activation solution. The solution can be prepared in advance.

(53) Typically:

(54) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml 0.5M HCl, 150 ml of distilled water (DI) and 1.4 g of NaCl. Wait until dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions.

(55) For the activation of the PAA layer, the glass strips are first of all immersed in an aqueous solution of pH=9 in order to rapidly hydrolyze the anhydrides, thus restoring the chemical formula of the PAA. Then the glass strips are placed at ambient temperature for 10 min in the activation solution. Rinsing with DI water is carried out.

(56) iii) Metallization

(57) The activated glass strip is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C.

(58) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(59) The activated glass strips are left for 10 minutes in order to have a complete and homogeneous metallization.

(60) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(61) iv) Adherence/Adhesion of the Metal Coating to the Substrate

(62) The adherence/adhesion of the metal layer is determined by applying the standardized Scotch tape test ASTM D3359.

(63) v) Comparative Substrate

(64) By way of comparison, a glass strip which has not been covered with a PAA layer was metalized by immersion in the palladium acetate activation solution described above. Due to the hydrophilic nature of the glass substrate, the palladium ions are adsorbed on the surface. This strip is subsequently transferred into the electroless bath and the metallization process takes place. A rinsing operation of water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 200 nm.

(65) vi) Results

(66) FIG. 1 shows:

(67) 1-a): photograph of a glass strip metalized over a portion (right-hand part); the glass which has not been coated with PAA in the left-hand part.

(68) 1-b): residues of the layer of bonding substance of the Scotch Tape® which has been used to carry out the adhesion test and which have remained adhesively bonded to the metal are observed. There is thus cohesive failure of the adhesive tape used for the adhesion test. The adhesive strength of the metal on the glass is thus greater than that of the bonding substance of the adhesive on its own band (which is rarely observed).

(69) 1-c) and 1-d): comparative example: metallization without PAA. The adhesion test with adhesive tape carried out on a portion of the metalized strip (black circle) shows the detachment of the metal film. At different locations (red circles), it is observed that the internal stress of the metal film is sufficient to spontaneously produce a partial detachment of the metal film.

Example 1-b/: Full Surface Metallization of a Glass Surface with a PAA Film with a Conforming Residual Thickness. (Heat Treatment)

(70) i) Coating and Immobilization of the Coating of Polymer with Acrylic Acid (PAA).

(71) A PAA (M.sub.n 130 000) solution with a concentration of 5 mg in 10 ml of ethanol is prepared by dissolution.

(72) A glass strip of microscope slide type (7.5×2.5 cm) is degreased (washing with a surfactant typically followed by an alcohol rinsing) and then dried by a heat gun for one minute at a temperature exceeding 200° C. without exceeding 300° C.

(73) For a metallization of full surface type, the PAA solution is applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogenous PAA film with a thickness of 10 nm. The deposition of PAA takes place then on both sides of the glass strip.

(74) The glass strips coated by the PAA are then typically rinsed with deionized water in order to remove the nonadsorbed PAA chains. The polyelectrolytic interactions govern the persistence of a thin residual film of a few nanometers (less than 5 nm). This residual film is subsequently heat treated by a heat gun for 90 seconds at a temperature exceeding 200° C. and not exceeding 300° C.

(75) ii) Activation with Palladium

(76) Preparation of the activation solution. The solution can be prepared in advance.

(77) Typically:

(78) 13 mg of Pd(NH.sub.3).sub.4Cl.sub.2 per 1 ml of deionized water. As the PAA film is thin, unlike the preceding example, the anhydride form is immersed directly in the palladium solution for 2 minutes. Hydration of the anhydrides and the complexing of the palladium take place concomitantly. A drying operation with the nitrogen blower is carried out.

(79) iii) Metallization

(80) The activated glass strip is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C. The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(81) The activated glass strips are left for 10 minutes in order to have a complete and homogeneous metallization.

(82) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(83) iv) Results

(84) FIG. 1-e) shows that a PAA film of a residual thickness (less than 5 nm), by virtue of its perfectly conforming nature, makes it possible to obtain a metal layer of high optical quality of “mirror finish” type. Furthermore, a test with the adhesive tape was carried out and no detachment was observed.

Example 1-c/: Localized Metallization of a Glass Surface. (Heat Treatment)

(85) i) Coating and Immobilization of the PAA Coating.

(86) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(87) A glass strip of microscope slide type (7.5×2.5 cm) is degreased (washing with a surfactant followed by an alcohol rinsing) and then dried (by a dry nitrogen gas blower and then by placing in an oven at 100° C. for 15 min).

(88) For a localized metallization, the PAA solution is applied with a stencil (masking) and a sprayer. The pattern of the adhesive stencil is in this instance drops of water (FIG. 2).

(89) The adhesive stencil is removed after drying the PAA layer.

(90) The glass strips coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(91) ii) Activation.

(92) Preparation of the activation solution. The solution can be prepared in advance.

(93) Typically:

(94) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2). 50 ml of 0.5M HCl, 150 ml of DI H.sub.2O and 1.4 g of NaCl. Wait until dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions.

(95) For the activation of the PAA layer, the glass strips are first of all immersed in an aqueous solution of pH=9 in order to rapidly hydrolyze the anhydrides and to thus restore the chemical formula of the PAA. Then the glass strips are placed at ambient temperature for 10 min in the activation solution. Rinsing with DI water is carried out.

(96) iii) Metallization.

(97) The activated glass strip is immersed in the electroless bath regulated at the temperature of 34° C.

(98) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(99) The activated glass strips are left for 10 minutes in order to have a complete and homogeneous metallization.

(100) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(101) iv) Results

(102) FIG. 2 shows that only the regions initially coated with PAA have been metalized.

Example 1-d/: Full Surface Metallization of a PVC Surface. (VUV Radiative Treatment)

(103) Coating and immobilization of the PAA coating.

(104) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(105) The flexible PVC sheet (format and manufacture for a credit card) is degreased (typically washing with a surfactant typically followed by an alcohol rinsing) and then dried (typically by a dry nitrogen gas blower).

(106) For a metallization of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm. The PAA deposition will take place then on both sides of the PVC sheet (FIG. 3).

(107) The PVC sheets are typically subjected to irradiation by VUV (Vacuum Ultraviolet) radiation for two minutes at a distance of 15 cm in an atmosphere purged of air by flushing with thy nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with maximum at 172 nm.

(108) ii) Activation.

(109) Preparation of the activation solution. The solution can be prepared in advance.

(110) Typically:

(111) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of DI H.sub.2O and 1.4 g of NaCl. Wait until dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions.

(112) For the activation of the PAA layer, the PVC sheets are placed at ambient temperature for 10 min in the activation solution. Rinsing with DI water is carried out.

(113) iii) Metallization.

(114) The activated PVC sheet is immersed in the electroless bath regulated at the temperature of 34° C.

(115) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(116) The activated PVC is left for 10 minutes in order to have a complete and homogeneous metallization.

(117) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(118) iv) Comparative Substrate

(119) By way of comparison, a PVC sheet which has not been covered with a PAA layer is immersed in the solution of activator based on palladium acetate described above. However, due to the hydrophobic nature of this material, the Pd.sup.2+ ions cannot be adsorbed on the substrate and initiate the metallization process.

(120) v) Results

(121) The metalized (activation and metallization) region corresponding to the presence of the PAA coating is presented in FIG. 3-a). FIG. 3-b) shows the result of the same experiment but in the absence of coating and immobilization of a PAA coating.

Example 1-e/: Full Surface Metallization of a PTFE Support. (VUV Radiative Treatment)

(122) Plasma activation of the surface of the Teflon.

(123) An argon plasma treatment of 10 minutes makes it possible for the surface of the support made of PTFE to be homogeneously wetted by the PAA solution and to thus deposit a PAA film of homogeneous thickness. On the face not exposed to the plasma, the wettability was not sufficient to coat the PTFE with the PAA film.

(124) ii) Coating and Immobilization of the PAA Coating.

(125) A PAA (M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(126) For a metallization of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm.

(127) The PTFE supports coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(128) At this stage, the PAA is in the form of anhydride functional groups. An immersion for 10 minutes in water makes it possible to hydrolyze the anhydride functional groups and to restore the chemical form of the PAA.

(129) iii) Activation with Palladium.

(130) Preparation of the activation solution. The solution can be prepared in advance.

(131) Typically:

(132) 70 mg of palladium acetate Pd(CH.sub.3CO.sub.2).sub.2, 50 ml of 0.5M HCl, 150 ml of DI H.sub.2O and 1.4 g of NaCl. Wait until the dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions.

(133) For the activation of the PAA layer, the PTFE supports are placed at ambient temperature for 10 min in the activation solution. A rinsing operation with DI water is carried out.

(134) iv) Metallization.

(135) The activated PTFE support is immersed in the electroless bath regulated at the temperature of 34° C.

(136) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(137) The activated PTFE is left for 10 minutes in order to have a complete and homogeneous metallization.

(138) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(139) v) Comparative Substrate

(140) By way of comparison, PTFE supports which have not been covered (FIG. 3-c) or which have been poorly covered (FIG. 3-d) with a PAA layer are immersed in the activated solution based on palladium acetate described above. However, due to the hydrophobic nature of this material, the Pd.sup.2+ ions and/or the PAA coating cannot be adsorbed on the substrate and make possible the development of the metallization process.

(141) vi) Results

(142) FIG. 3-e shows the metalized (activation and metallization) region corresponding to the presence of the PAA coating.

Example 1-f/: Local Metallization of a PVC Surface. (Radiative Treatment)

(143) i) Coating and Immobilization of the PAA Coating.

(144) A PAA (M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(145) The flexible PVC sheet (format and manufacture for a credit card) is degreased (washing with a surfactant typically followed by an alcohol rinsing) and then dried (typically by a dry nitrogen gas blower).

(146) The deposition of the PAA solution is localized in this example by using a writing pen dipped beforehand in the PAA solution (FIG. 4).

(147) The PVC sheets are typically subjected to irradiation by VUV radiation for two minutes at a distance of 15 cm in an atmosphere purged of air by flushing with dry nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with maximum at 172 nm.

(148) ii) Activation.

(149) Preparation of the activation solution. The solution can be prepared in advance.

(150) Typically:

(151) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of DI H.sub.2O and 1.4 g of NaCl. Wait until dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions.

(152) For the activation of the PAA layer, the PVC sheets are placed at ambient temperature for 10 min in the activation solution. Rinsing with DI water is carried out.

(153) iii) Metallization.

(154) The activated PVC sheet is immersed in the electroless bath regulated at the temperature of 34° C.

(155) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(156) The activated PVC is left for 10 minutes in order to have a complete and homogeneous metallization.

(157) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(158) iv) Results

(159) FIG. 4 shows that a localized metallization of the PVC has been obtained: the metalized parts were obtained using the PAA solution as an ink. The pattern was produced with a writing pen.

Example 2: Immobilization of the PAA on Different Polymer Supports

Example 2-a/: Thermal Immobilization of PAA on Polyimide

(160) i) Coating of the Support.

(161) A PAA (M.sub.n 130 000) solution with a concentration of 100 mg in 10 ml of ethanol is prepared by dissolution.

(162) A flexible polyimide (PI) sheet of 50 μm is degreased (washing with a surfactant followed by an alcohol rinsing) and then dried (by a dry nitrogen gas blower and then by placing in an oven at 100° C. for 15 min).

(163) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 150 to 250 nm. The PAA deposition will then take place on both sides of the polyimide sheet (FIG. 5).

(164) ii) Immobilization of the PAA on the Support

(165) The flexible polyimide sheets coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(166) At this stage, the PAA is in the form of anhydride functional groups which can be used in order to be coupled to other complementary functional groups of advantageous materials.

(167) An immersion in water for 10 minutes makes it possible to hydrolyze the anhydride functional groups and to restore the chemical form of the PAA.

(168) FIG. 5 shows that the peaks related to the presence of a PAA film of 200 nm on the PI persist after a washing operation in water lasting 120 h.

Example 2-b/: Immobilization by Subjecting to VUV Irradiation a PAA Film on a Flexible Polyethylene Terephthalate (PET) Sheet

(169) 1) Coating of the Support

(170) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(171) A flexible polyethylene terephthalate (PET) sheet of 50 μm is degreased (typically washing with a surfactant typically followed by an alcohol rinsing) and then dried (typically by a dry nitrogen gas blower).

(172) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm. The PAA deposition will take place then on both sides of the PET sheet (FIG. 6).

(173) ii) Immobilization of the PAA on the Support

(174) The flexible PET sheets coated with the PAA are then typically irradiated by VUV (Vacuum Ultraviolet) radiation for 2 minutes at a distance of 15 cm in an atmosphere purged of air by flushing with dry nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with a maximum of 172 nm.

(175) The persistence of the PAA film in its carboxylate form due to the rinsing with water, irradiated side, and the removal of the PAA, nonirradiated side, are seen in FIGS. 6c and 6d.

Example 2-c/: Immobilization by Subjecting to VUV Irradiation a PAA Film on a Flexible Polyethylene (PE) Sheet

(176) i) Coating of the Support

(177) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(178) A flexible Polyethylene (PE) sheet of 50 μm is degreased (washing with a surfactant followed by an alcohol rinsing) and then dried (by a dry nitrogen gas blower).

(179) For a coating of full surface type, the PAA solution is applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm. The PAA deposition will take place then on both sides of the PE sheet (FIG. 7). An oxidative pretreatment of the surface by UV-ozone or oxygen plasma can be carried out before the coating thereof in order to improve the wetting of the PAA solution.

(180) ii) Immobilization of the FAA on the Support

(181) The flexible PE sheets coated with the PAA are then irradiated by VUV (Vacuum Ultraviolet) radiation for 2 minutes at a distance of 15 cm in an atmosphere purged of air by flushing with dry nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with a maximum at 172 nm.

(182) The persistence of the PAA film in its acid and carboxylate form due to the rinsing with water, irradiated side, and the removal of the PAA, nonirradiated side, are seen in FIGS. 7c and 7d.

Example 3: Immobilization and Structuring by Subjecting to VUV Irradiation a Thin Film of PAA on Gold

(183) This example demonstrates the possibility of immobilizing and structuring a thin film of PAA on any one surface at submillimetric scales by photolithographic methods.

(184) Coating of the Support

(185) A PAA (M.sub.n 130 000) solution with a concentration of 100 mg in 10 ml of ethanol is prepared by dissolution.

(186) A gold surface (gilded glass strip) is cleaned by UV-ozone treatment for 5 minutes in order to remove the surface organic contaminants.

(187) For a coating of full surface type, the PAA solution is applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 150 to 250 nm.

(188) ii) Structuring of the Coated Support and Immobilization of the PAA

(189) A mask is deposited by direct contact on the gold surface coated with the PAA and then the assembly is irradiated with VUV (Vacuum Ultraviolet) radiation for 15 minutes at a distance of 7 cm in an atmosphere purged of air by flushing with dry nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with a maximum at 172 nm.

(190) After irradiation, the mask is removed and the sample is copiously washed with water. The PAA film which has not been subjected to the irradiation is removed by the washing with water, whereas the irradiated film for its part withstands this washing operation. The experiment is illustrated by FIG. 8. The photographic image (at the top) of the gold surface after the VUV irradiation and the effective removal of the nonirradiated PAA by washing with water is examined. The white lines of the optical image correspond to the drying rims. Within the white lines, the PAA film is grafted by subjecting to irradiation and withstands copious rinsing with water. Outside the white lines, the PAA film has been removed by the copious rinsing with water.

(191) The black line represents the line measured by profilometry (at the bottom at the left) and makes it possible to see that the difference of thickness between the irradiated region and the nonirradiated region is of the order of 200 nm, i.e. of the same order of magnitude as the initial thickness of the PAA film on the gilded substrate. This demonstrates i) the lack of effect of the washing with water on the PAA deposit in the irradiated region and ii) the effectiveness of the washing in removing virtually all of the deposit in the nonirradiated region.

(192) This is confirmed by the IR analyses (at the bottom on the right) carried out in the different regions after washing:

(193) i) in the irradiated region after washing with water, the absorption bands characteristic of the PAA film remain clearly visible and strong,

(194) ii) in the nonirradiated regions after washing with water, the very weak intensities detected confirm the virtually complete removal of the deposit.

Example 4: Structural Adhesive Bonding Via the Anhydride Groups. (Heat Treatment)

Example 4-a/: Adhesive Bonding of an Epoxy Resin to a Stainless Steel Surface

(195) i) Coating of the Support

(196) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(197) A stainless steel strip, mechanically polished down to a roughness of 1 μm (mirror), is degreased (typically washing with a surfactant typically followed by an alcohol rinsing) and then dried (typically by a dry nitrogen gas blower and then by placing in an oven at 100° C. for 15 min).

(198) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after the evaporation of the ethanol, a covering and homogenous PAA film with a thickness typically of 70 to 100 nm.

(199) ii) Immobilization of the PAA on the Support

(200) The stainless steel surfaces coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(201) The heating will make it possible to cause the PAA to adhere to the stainless steel, to form reactive anhydride groups and to crosslink the film by decarboxylation.

(202) iii) Structural Adhesive Bonding to the Coated Support

(203) Preparation of the epoxy resin of two-component type: Epiglass HT900 (epoxy resin and amine hardener) in an 80-20 proportion.

(204) The mixture is prepared and applied as a thin layer of 300 μm to the stainless steel (use of a stencil of screenprinting type). The bubbles are eliminated naturally in 5 minutes and a final drying is carried out at 100° C. for one hour.

(205) The epoxy film is applied to a virgin stainless steel surface (comparative substrate) and under the same conditions to a stainless steel surface with a PAA-anhydride coating.

(206) A standardized adhesion test with Scotch tape ASTM D3359 is carried out (“squares” tests with a six-bladed scratching tool).

(207) The test in which the Scotch tape is torn off the stainless steel which has been simply polished (comparative substrate) results in a significant detachment of the epoxy film beyond the cross-hatched region. The same test in which the Scotch tape is torn off the stainless steel coated with the PAA-anhydride does not show any detachment, even after several tests. The amine functional groups of the hardener, before the resin has completely hardened, have spontaneously reacted with the anhydride functional groups of the coated surface. The results and the chemical mechanism of grafting between the resin and the PAA-anhydride film are shown in FIG. 9.

Example 5: Control of the Surface Energy of a Substrate

Example 5-a/: A Hydrophilically Modified Hydrophobic Substrate (PVC)

(208) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(209) The flexible PVC sheet (format and manufacture for a credit card) is degreased (typically washing with a surfactant typically followed by an alcohol rinsing) and then dried (typically by a dry nitrogen gas blower). At this stage, the PVC surface is very hydrophobic.

(210) For a treatment of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm.

(211) The PVC sheets are typically subjected to irradiation by VUV (Vacuum Ultraviolet) radiation for two minutes at a distance of 15 cm in an atmosphere purged of air by flushing with dry nitrogen. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with maximum at 172 nm.

(212) The surface energy of the substrate is determined by the measurement of the contact angle. The contact angle measurements were carried out with a device of Apollo Instrument brand, controlled via the Sca 20 software.

(213) The results observed are shown in FIG. 10. The crude PVC is very hydrophobic when it is clean and exhibits a contact angle of approximately 100°. Its surface energy is low. Once modified by a grafted film of PAA, the surface energy is increased and the contact angle measured is approximately 30°.

Example 5-b/: A Hydrophobically Modified Hydrophilic Substrate (Glass Substrate Covered with a Gold Layer)

(214) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(215) A glass strip of microscope slide type (7.5×2.5 cm) covered with a gold layer (gilded substrate) is directly treated with UV-ozone for 5 min in order to remove the traces of organic contamination of atmospheric origin.

(216) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm. The glass strips coated with the PAA are then typically heated at 200° C. for 30 min in an ordinary oven at an atmospheric pressure and without specific precautions.

(217) The heating will make it possible to cause the PAA to adhere to the gilded substrate, to form reactive anhydride groups and to crosslink the film by decarboxylation.

(218) A molecule comprising a hydrophobic part (C.sub.11 alkyl group) and a primary amine functional group is applied to the activated surface, in a pure (undiluted) form, by laying down a drop and by then spreading it with the application of a coverglass on top, or in a form diluted in a solvent, for example of hexane or cyclohexane type, which does not interfere with the coupling reaction between the anhydrides and the amines (FIG. 11). (cf scheme below).

(219) The contact angle of the clean gold after a UV-03 treatment lies between 20 and 30°. This substrate coated with the PAA exhibits a contact angle typically between 30 and 50°. Then, when the C.sub.11 amine is grafted to the substrate coated with PAA, this contact angle reaches 100°. IR spectroscopy makes it possible to demonstrate the chemical reaction between the acid surface of the gilded substrate covered with PAA and the amine by the presence of the amide bands (FIG. 11).

(220) ##STR00005##

Example 6: Preparation of PAA Film with a Residual and Constant Thickness

(221) For biological applications in SPRI (surface plasmon resonance imaging), for example, or for applications for the preparation of reflecting surfaces (metalized surface of “mirror finish” optical quality), it is valued to have very fine and very homogeneous PAA layers (conforming to the surface).

(222) The methods of coating by projection or by transfer are limited in the quality of deposition by the stage of application and then of evaporation of the solvent, which are never perfectly homogeneous.

(223) PAA is a polyelectrolyte which can be adsorbed by electrostatic interactions on certain surfaces. These interactions develop over a distance which is dependent on the nature of the polymer and on the substrate and can consequently be variable. The balance of these different forces results in the deposition of a thin layer of perfectly defined thickness after several successive rinsing operations. The asymptotic thickness obtained after the rinsing operations is then governed by the surface.

(224) One method for the preparation of these thin conforming PAA layers consists in applying a PAA coating with a thickness greater than the desired thickness without specific precautions and in then removing, by rinsing, the PAA polymer chains which do not interact physically with the surface.

(225) By way of example, a PAA film is deposited by dipping-withdrawing (immersion-emersion) on a support made of gold (deposition of a gold layer on a glass strip) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm.

(226) Prolonged rinsing operations with water, which is a very good solvent for PAA, are subsequently carried out in order to remove the polymer which does not interact with the surface, until a residual PAA film of stable thickness is obtained.

(227) The residual films obtained on gold asymptotically converge toward a constant thickness of 15 nm, as is shown by the IR intensities of FIG. 12. This residual thickness is controlled by the polyelectrolytic interactions in connection with the surface properties.

(228) These films are highly reproducible in thickness and conform perfectly to the surface (FIG. 12).

(229) A final annealing at 200° C. for 30 minutes makes it possible to definitively stabilize the film and again to make use of either the anhydride or acid functional groups for chemical couplings.

(230) By way of example, it is possible to obtain the metallization of a glass strip with the “mirror finish” optical quality by applying the metallization process starting from a PAA coating layer of conforming residual layer type (cf example 1-b), FIG. 1-e).

Example 7: Coupling of Biological Molecules to a PAA Surface

(231) The stable coupling of biological molecules to a surface is an important objective of numerous analytical and medical diagnosis methods.

(232) The following example illustrates the possibility of chemically and covalently grafting proteins to an activated adhesion primer itself covalently grafted to a substrate.

(233) In a first step, activated surfaces are created and then these activated surfaces are used to carry out the coupling proper with the proteins.

(234) The coupling of the proteins is carried out conventionally for biologists by passing through the activated form of the acid, referred to as activated ester. This activated ester reacts favorably in a buffered medium with the amine groups of the proteins to create stable and hydrolysis-resistant amide bonds. For further information regarding such couplings, reference may be made to the work by Greg T Hermanson, “Bioconjugate Techniques”, 2nd edition, Elsevier, 2008.

(235) Two protocols have been followed in order to obtain the activated adhesion primer: a protocol for formation of activated esters in an organic medium and a protocol for formation of anhydrides in an aqueous medium. The subsequent coupling with the proteins is for its part always carried out in an aqueous medium.

(236) 1) Protocol for Activation in an Organic Medium of the Adhesion Primer.

(237) i) Preparation of the Activation Solutions. 40 mg of dicyclohexylcarbodiimide (DCC) are dissolved in 17 ml of acetonitrile 22 mg of N-hydroxysuccinimide (NHS) are dissolved in 13 ml of acetonitrile.

(238) ii) Condition for Activation of the PAA Surface:

(239) A PAA strip grafted in its acid form is immersed in a solution containing 8 ml of acetonitrile, 1 ml of the dicyclohexylcarbodiimide (DCC) solution and 1 ml of the N-hydroxysuccinimide (NHS) solution. The PAA surface is left to react for 30 minutes.

(240) iii) Condition for the Coupling with the Proteins:

(241) A 1 mg/ml solution of protein (calmodulin) in DI water at a pH equal to 6 is prepared.

(242) The PAA surface activated according to the conditions described above is immersed in 2 ml of the protein solution. The combination is placed in an incubator at 37° C. and under gentle stirring for 1 h.

(243) FIG. 13 illustrates the formation of activated esters at the surface of the PAA film (FIG. 13-a) and then the result of the coupling with the protein: appearance of a component bonded to the protein (FIG. 13-b). As the PAA film is not swollen by the acetonitrile, the NHS and DCC reactants have not penetrated into the PAA layer and only the surface carboxylic acid (COOH) groups are modified. 2) Protocol for activation in an aqueous medium of the adhesion primer:

(244) i) Preparation of the Activation Solutions. 24 mg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) are dissolved in 10 ml of DI water. 16 mg of N-hydroxysuccinimide (NHS) are dissolved in 10 ml of DI water.

(245) ii) Condition for Activation of the PAA Surface:

(246) A grafted PAA strip in its acid form is immersed in a solution containing 8 ml of DI water at pH=4.5, 1 ml of the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) solution and 1 ml of the N-hydroxysuccinimide (NHS) solution. The strip is left to react for 30 minutes.

(247) iii) Condition for the Coupling of the Proteins:

(248) A 1 mg/ml solution of protein (calmoduline) in DI water at a pH equal to 6 is prepared.

(249) The PAA surface prepared according to the conditions described above is immersed in 2 ml of the protein solution. The assembly is placed in an incubator at 37° C. and under gentle stirring for 1 h.

(250) FIG. 14 illustrates the formation of the anhydrides by the chemical route in an aqueous medium in the presence of NHS and EDC (FIG. 14-a), and the result of the coupling with the protein (FIG. 14-b). It was confirmed beforehand that the anhydride functional groups persisted after immersion of the activated support in DI water at a pH equal to 6 for 15 minutes (FIG. 14-c). Thus, the disappearance of the anhydride functional groups after coupling with the protein is indeed the result of the reaction which took place between these functional groups and the protein.

Example 8: Thermal Immobilization of PAA on Carbon Felt for the Preparation of Filtering Elements for Industrial Heavy Metals (Cu, Zn, Ni, and the Like) in the Treatment of Liquid Effluents

(251) It is a matter of capturing salts of metal elements in solution on filters composed of carbon felt, which filters are coated with polyacrylic acid.

(252) i) Manufacture of the Active Felts:

(253) Disks of carbon felts (RVG 4000—0.7 m.sup.2/g—d=0.088) with a diameter of 2.8 cm (340 mg) are subjected to an Ar-02 [90-10%] plasma treatment for 10 minutes in order to become wetting. This treatment limits the withdrawal of the liquid during the drying and makes it possible to obtain covering coatings with the whole of the fibers.

(254) A PAA, Mn 130 000, solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(255) A solution of polyethyleneimine (PEI), of MW 25000, of 5 mg in 10 ml of DI water is prepared by dissolution.

(256) A first impregnation is carried out with a 5 mg/10 ml aqueous polyethyleneimine (PEI) solution.

(257) The felt is filled using a Pasteur pipette until it is visually detected that the impregnation is complete.

(258) The felt is left to dry. The PEI (polymer exhibiting positive charges) coating reinforces the polyelectrolytic properties of the PAA (negatively charged) and results in a better subsequent encasing of the fibers by the PAA.

(259) A second impregnation is carried out with a 50 mg/10 ml solution of PAA in ethanol until it is visually detected that the impregnation is complete.

(260) The felt is left to dry.

(261) A curing is carried out at 200° C. for 30 min.

(262) The process makes possible an encasing which covers individual fibers of the carbon felt. Interference colors over the whole of the fibers, whether at the surface of the felt or inside the felt, are detected by optical microscopy.

(263) After the heat treatment, the PAA is in the anhydride chemical form. In order to restore the carboxylic acid form which will capture the heavy metals, the hydrolysis of the anhydrides is carried out at pH=9 for 10 minutes.

(264) The film thus manufactured is chemically stable on the fibers. For example, it withstands a basic aqueous solution of pH=10 which is nevertheless an excellent solvent for PAA).

(265) The dry residue after drying is 16 mg and represents a mean thickness of PAA film encasing the fibers of 70 nm.

(266) ii) Treatment on a Column of Solutions Containing Copper Salts.

(267) 13 felts thus prepared (which represents 211 mg of PAA immobilized on the 13 felts) are placed in a column (100 ml plastic syringe), and 2.4 l of a 45 mg/l solution of Cu.sup.++ in faucet water are slowly filtered through the column.

(268) With regard to the first liter filtered, the copper concentration of the filtrate recovered is 100 μg/L, which demonstrates the effectiveness of the capturing.

(269) In the end, a fixing capacity (expressed as milligrams of copper per gram of felt) of 22 mg/g is observed. With respect to the weight of PAA, 22 mg of fixed copper are obtained per 50 mg of PAA, i.e. a value very close to the expected stoichiometry (two COO— functional groups per 1 Cu.sup.++ ion). In other words, in the system according to the invention, 440 mg of Cu are captured per gram of PAA immobilized on the felt; this result is superior to the best resins in the bead form, where 50 to 200 mg/g are generally observed.

Example 9: Electroless Metallization of Woven Kevlar Fibers by Nickel and Copper

(270) A/ Coating and Immobilization of the Polyacrylic Acid (PAA) Coating

(271) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(272) A fabric of woven Kevlar fibers of 9 cm.sup.2 without specific cleaning.

(273) For a complete metallization covering the whole of the fibers and each fiber individually, the PAA solution is applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness of 50 to 70 nm. The PAA deposition is carried out then over all the fibers.

(274) The fabric of Kevlar fibers coated with the PAA is then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(275) For the metallization of the PAA layer, the Kevlar fabric is first of all immersed in an aqueous solution of pH=9 in order to rapidly hydrolyze the anhydrides, thus restoring the chemical form of the PAA. A rinsing operation with DI water is carried out.

(276) B/ Electroless Nickel Metallization of PAA-Coated Kevlar Fabric

(277) B1) Nickel Metallization Activation

(278) Preparation of the activation solution. The solution can be prepared in advance.

(279) Typically:

(280) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of distilled water (DI) and 1.4 g of NaCl. After complete dissolution, the pH is adjusted to between 5 and 6 with concentrated NaOH and HCl solutions.

(281) B2) Electroless Nickel Metallization

(282) The fabric of activated fibers is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C.

(283) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(284) The tissue of activated fibers is left for ten minutes in order to have a complete and homogeneous metallization.

(285) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

(286) C/ Electroless Copper Metallization of PAA-Coated Kevlar Fabric

(287) C1) Copper Metallization Activation

(288) The PAA-coated Kevlar fabric is immersed in an ammonium cupric sulfate solution at pH=12 for 5 min. A rinsing operation with DI water is carried out before the reduction of the copper salts by 2.5 g/l NaBH.sub.4 in 0.1M NaOH medium (pH=13). The reduction bath is regulated at 50° C. and the reduction is typically carried out for 5 to 10 min. The fabric is rinsed with DI water.

(289) C2) Electroless Copper Metallization.

(290) The electroless copper bath is a bath sold by Pegastech which metalizes at 2 μm per hour at 45° C. and pH=13.

(291) A Kevlar fabric metalized with copper is obtained.

Example 10: Aeronautic-Type Carbon-Epoxy Composite Metallization

(292) A/ Coating and Immobilization of the Polyacrylic Acid (PAA) Coating

(293) A PAA (M.sub.n 130 000) solution with a concentration of 50 mg in 10 ml of ethanol is prepared by dissolution.

(294) A sheet of carbon-epoxy composite of aeronautic type.

(295) For a complete metallization covering the sheet of carbon-epoxy composite individually, the PAA solution is applied by dipping-withdrawal (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness of 50 to 70 nm. The PAA deposition takes place then on the fraction of sheet immersed.

(296) The sheet of carbon-epoxy composite coated with the PAA is then typically heated at 200° C. for 30 min in an ordinary oven at atmospheric pressure and without specific precautions.

(297) For the metallization of the PAA layer, the sheet of carbon-epoxy composite is first of all immersed in an aqueous solution of pH=9 in order to rapidly hydrolyze the anhydrides, thus restoring the chemical form of the PAA. A rinsing operation with DI water is carried out.

(298) B/ Electroless Nickel Metallization of the PAA-Coated Sheet of Carbon-Epoxy Composite

(299) B1) Nickel Metallization Activation

(300) Preparation of the activation solution. The solution can be prepared in advance.

(301) Typically:

(302) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of distilled water (DI) and 1.4 g of NaCl. After complete dissolution, the pH is adjusted to between 5 and 6 with concentrated NaOH and HCl solutions. A rinsing operation with DI water is carried out.

(303) B2) Electroless Nickel Metallization

(304) The sheet of carbon-epoxy composite is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C.

(305) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(306) The sheet of carbon-epoxy composite is left for 10 minutes in order to have a complete and homogeneous metallization.

(307) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm. In FIG. 17, it is observed that the lower part has been coated with grafted PAA and then metalized. The metallization has taken place only on the PAA-treated part.

(308) An electrical measurement with a conventional measuring device typically observes a resistance of 30 ohms between the two electrodes 5 cm apart. The metal coating is thus conductive.

Example 11: Metallization of Polymer Substrates of ABS Type

(309) A/ Coating and Immobilization of the Polyacrylic Acid (PAA) Coating

(310) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(311) The ABS surfaces are convex surfaces of mirror quality. They concern virgin components made of ABS used in particular in bathroom installations, such as, for example, bath plugs. The components are prepared with a simple degreasing with a surfactant and a rinsing operation with water and are then dried (typically by a dry nitrogen gas blower).

(312) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogeneous PAA film with a thickness typically of 50 to 70 nm.

(313) The samples are typically subjected to irradiation by VUV irradiation for two minutes at a distance of 15 cm in an atmosphere purged of air by flushing with thy nitrogen for 10 minutes. The characteristics of the VUV lamp are: excimer lamp of the Osram brand, Xeradex model. Power of 140 W. Radiation 150 to 190 nm with a maximum at 172 nm. These characteristics remain the same for the following examples.

(314) The immobilization of the thin PAA films is tested by a washing operation with ethanol and with water, which are very good solvents for PAA. The resistance of the films is observed over all the substrates. The tests of rinsing with alcohol or water before the irradiation very clearly show the complete removal of the PAA.

(315) B/ Electroless Nickel Metallization of the ABS Substrate Coated with PAA

(316) B1) Nickel Metallization Activation

(317) Preparation of the activation solution. The solution can be prepared in advance.

(318) Typically:

(319) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of distilled water (DI) and 1.4 g of NaCl. Wait until dissolution is complete.

(320) Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions. A rinsing operation with DI water is carried out.

(321) B2) Electroless Nickel Metallization

(322) The ABS substrate is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C.

(323) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(324) The ABS substrate is left for 10 minutes in order to have a complete and homogeneous metallization.

(325) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.

Example 12: Metallization of Polymer Substrates of COP Type

(326) A/ Coating and Immobilization of the Polyacrylic Acid (PAA) Coating

(327) A PAA (typically M.sub.n 130 000) solution with a concentration typically of 50 mg in 10 ml of ethanol is prepared by dissolution.

(328) The surfaces of COP (Cyclic Olefin Polymer) sold by Zeon (Zeonex®) are prepared with a simple degreasing operation with a surfactant and a rinsing operation with water and then dried (typically by a dry nitrogen gas blower).

(329) For a coating of full surface type, the PAA solution is typically applied by dipping-withdrawing (immersion-emersion) in order to obtain, after evaporation of the ethanol, a covering and homogenous PAA film with a thickness typically of 50 to 70 nm.

(330) The samples are typically subjected to irradiation by VUV radiation for 2 minutes at a distance of 4 cm in an atmosphere purged of air by flushing with dry nitrogen for 10 minutes.

(331) The immobilization of the thin PAA films is tested by a washing operation with ethanol and with water, which are very good solvents for PAA. The resistance of the films is observed over all the substrates. The tests of rinsing with alcohol or water before irradiation very clearly show the complete removal of the PAA.

(332) B/ Electroless Nickel Metallization of the COP Substrate Coated with the PAA

(333) B1) Nickel Metallization Activation

(334) Preparation of the activation solution. The solution can be prepared in advance.

(335) Typically:

(336) 70 mg of palladium acetate (Pd(CH.sub.3CO.sub.2).sub.2), 50 ml of 0.5M HCl, 150 ml of distilled water (DI) and 1.4 g of NaCl. Wait until dissolution is complete. Adjust the pH to between 5 and 6 with concentrated NaOH and HCl solutions. A rinsing operation with DI water is carried out.

(337) B2) Electroless Nickel Metallization

(338) The COP substrate is immersed in an electroless bath (that is to say, a nonelectrolytic bath) regulated at the temperature of 34° C.

(339) The bath is typically a commercial Niposit™ PM 988 bath. Its pH is 9.4. The reducing agent is sodium hypophosphite (NaH.sub.2PO.sub.2.H.sub.2O).

(340) The COP substrate is left for 10 minutes in order to have a complete and homogeneous metallization.

(341) A rinsing operation with water and then a drying operation with the dry gas blower are sufficient. The thickness of the nickel film is typically 500 nm.