Formation of organic electro-grafted films on the surface of electrically conductive or semi-conductive surfaces
The invention relates to a method for grafting an organic film onto an electically conductive or semiconductive surface by electro-reduction of a solution, wherein the solution comprises one diazonium salt and one monomer bearing at least one chain polymerizable functional group. During the electrolyzing process, at least one protocols consisting of an electrical polarization of the surface by applying a variable potential over at least a range of values which are more cathodic that the reduction or peak potential of all diazonium salts in said solution is applied. The invention also relates to an electrically conducting or semiconducting surface obtained by implementing this method. The invention further relates to electrolytic compositions.
1. An electrically conducting or semiconducting surface, comprising an organic film layer, grafted on said surface, or portion of said surface, and an outer layer adhered to the organic film layer by interdigitation, wherein the organic film layer comprises a macro-object comprising a group that can be involved in propagation chain reactions and which is precursor of said organic film layer, and a moiety of an aryldiazonium salt or its electro-reduction by-products,
wherein the organic film layer has a thickness from 10 nm to 10 μm; and
wherein the organic film layer is not homogeneous in a direction perpendicular to the surface; wherein the macro-object is selected from the compounds of formula:
A-P
A-P-B
P(A)n
[M(A)]n
A-[M(B)]n
A-[M(B)]—C
A-P-[M(B)]n
A-P-[M(B)]—C
in which:
(i) P is a macrostructure chosen from organic or inorganic oligomers and polymers; polymers obtained by polycondensation of one or more reagents; polysiloxanes; poly(orthoesters); polyphosphates; parylene polymers; conducting polymers; oligopeptides and proteins; nucleic acid molecules; polysaccharides; substituted or unsubstituted porphyrins; substituted or unsubstituted phthalocyanins; and polymers, copolymers, macromers or telechelics formed from substituted monomers or from substituted macromolecules selected from organic or inorganic oligomers and polymers, polymers obtained by polycondensation of one or more reagents, polysiloxanes, poly(ortho-esters), polyphosphates, parylene, conducting polymers, oligopeptides and proteins, nucleic acid molecules, polysaccharides, substituted porphyrins, substituted phthalocyanins, which may or may not be substituted;
(ii) n is an integer greater than or equal to 1;
(iii) M is a constituent monomer unit of the polymer of type P selected from organic or inorganic oligomers and polymers, polymers obtained by polycondensation of one or more reagents, polysiloxanes, poly(orthoesters), polyphosphates, parylene polymers, conducting polymers, oligopeptides and proteins, nucleic acid molecules, polysaccharides, polymers formed from substituted monomers or from substituted macromolecules as recited in (i), macromers or telechelics based on the monomers and/or macromolecules as recited in (i), copolymers and/or mixtures which can be formed from these polymers, from their constituent monomers or from the macromolecules above, which may or may not be substituted; and
(iv) A, B and C, which may be identical or different, are chosen from chain polymerizable groups selected from vinyl groups or cleavable cyclic molecules,
A, B and C being linked via covalent, ionic or dative bonds, or via hydrogen bonding, with the macrostructural portion P or the monomeric portion M.
2. The surface of claim 1 , wherein the organic film layer is richer in diazonium and its electro-reduction by-products close to the surface, while farther from the surface, the organic film layer is richer in polymer.
3. The surface of claim 1 , wherein P is selected from the group consisting of proteins, nucleic acids, and polysaccharides.
4. The surface of claim 3 , wherein P is selected from the group consisting of antigens, enzymes, growth factors, antibodies, and collagens.
5. The surface of claim 3 , wherein the nucleic acid is selected from the group consisting of single- and double-stranded DNA, and single- and double-stranded RNA.
6. The surface of claim 3 , wherein the polysaccharides are selected from the group consisting of cellulose, substituted celluloses, chitosans, substituted or functionalized chitosans, dextrans and substituted or functionalized dextrans, amyloses, pectins, starch and heparin.
7. An object comprising a surface of claim 1 .
8. The object of claim 7 , wherein the object is biocompatible.
9. The object of claim 7 , wherein the object is a stent.