Method for producing copper nanoparticles and use of said particles

Abstract

The invention relates to copper nanoparticles and to a method for producing them, including the following steps: dissolving at least one copper salt, oxide or hydroxide in distilled water in a container; dissolving at least one stabilizer in distilled water in a container; mixing the two solutions in a reactor; adding a primary complexing agent; adding an alkali; adding an anti-foaming agent; adding at least one reducing agent, stopping the reaction by cooling to a temperature reaction between 0° C. and 25° C. while maintaining the stirring; adding at least one antioxidant; adding at least one secondary complexing agent; and maturing and washing the mixture; The invention also relates to the use of copper nanoparticles.

1 . A method for obtaining copper nanoparticles, wherein it comprises the following stages:
 i) dissolving in a container at least one copper salt, oxide or hydroxide in water, preferably distilled water, until a solution of a concentration of 0.1 M to 1.5 M is obtained;   ii) dissolving in a container at least one stabilizer in water, preferably distilled, until a stabilizer solution of a concentration of 0.5 to 20 M is obtained;   iii) mixing the two solutions in a reactor and maintaining with stirring in the range of between 5 to 10,000 rpm for a time between 1 min and 24 hours;   iv) adding to the reaction mixture obtained in step iii) at least one primary complexing agent in a molar concentration from 5 to 12 M, stirring the complexing reaction mixture for a time between 1 min and 24 hours;   v) adding an alkali to the above reaction mixture, until the mixture is adjusted to a pH>5;   vi) then adding a defoamer to the reaction mixture in a concentration not greater than 1% of the total mixture and heating the reaction mixture between 25-120° C. with stirring in the range of between 5 to 10,000 rpm;   vii) adding at least one reducer to the reaction mixture of step vi) with stirring in the range of 5 to 10,000 rpm which is in a molar concentration from 0.5 to 3 M; stirring the reaction mixture for a time between 1 min and 24 hours of reduction;   viii) stopping the reaction by cooling to a reaction temperature between 0° C. to 25° C. while maintaining stirring in the range of 5 to 10,000 rpm;   ix) adding at least one antioxidant pre-dissolved in distilled water with a molar concentration from 0.5 to 3 M;   x) adding at least one secondary complexer pre-dissolved in distilled water in a molar concentration of 0.1 to 1.5 M;   xi) maturing the mixture of step x) for a time of 1 min to 15 days, at a temperature of 10° C. to 70° C. with or without stirring in the range of 5 to 10,000 rpm;   xii) washing the nanoparticles by centrifugation and/or dialysis with at least one solvent.   
     
     
         2 . The method for obtaining copper nanoparticles according to  claim 1 , wherein the copper salt, oxide or hydroxide of stage i) is selected from the group consisting of copper (I) chloride (CuCl), Copper (II) Chloride (CuCl 2 ), copper (I) cyanide (CuCN), copper sulfate (CuSO 4 ), copper nitrate (Cu(NO 3 ) 2 , copper acetate (CH 3 COO) 2 Cu, copper carbonate (CuCO 3 ), copper acetylacetonate C 5 H 7 CuO 2 , copper (II) perchlorate, copper (II) stearate, copper (II) ethylenediamine, copper (II) trifluoroacetylacetonate, copper (II) hexafluoroacetylacetonate, copper (II) formate, copper (II) methacrylate, copper (II) neodecanoate, copper (II) ethylhexanoate, copper (II) trifluoroacetate, copper (I) oxide (Cu 2 O), copper (II) oxide (CuO), copper (II) hydroxide (CuOH) 2 . 
     
     
         3 . The method for obtaining copper nanoparticles according to  claims 1  to  2 , wherein the stabilizer of step ii) is selected from the group consisting of polymers such as poly (vinylpyrrolidone) (PVP), polyvinyl alcohol, polycarbonates, polyphenols, polyethylene glycol and polyols such as ethylene glycol, diethylene glycol, tri-ethylene glycol, propylene glycols, alkyldiols such as butanediols, dipropylene glycol and polyethylene glycols, chitosan and its derivatives, polyacids and derivatives thereof, mercaptoalkanoates, and oxybenzoic acids; wherein the polyacids include one or more of those selected from the group of poly (acrylic acid), poly (maleic acid), poly (methyl methacrylate), poly (acrylic acid-co-methacrylic acid), poly (maleic acid-co-acrylic acid), and poly (acrylamide-coacrylic acid), cellulose acetates, polyvinylacetates, polysulfones, polyphenylsulphones, polyethersulfones, polyketones, polyetherketones, polyesters and their derivatives, including one or more of those selected from the group of ammonium, sodium or potassium salts of the polyacids. 
     
     
         4 . The method for obtaining copper nanoparticles according to  claims 1  to  3 , wherein the primary complexing agent of step iv) is selected from the group consisting of ammonia (NH 3 ), ammonium hydroxide and the group of primary amines and secondary agents such as isopropylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, terbutylamine, aniline or Schiff bases. 
     
     
         5 . The method for obtaining copper nanoparticles according to  claims 1  to  4 , wherein the alkali of step v) is selected from sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), magnesium hydroxide (Mg(OH) 2 ), barium (Ba(OH) 2 ), calcium (Ca(OH) 2 ) and Arrhenius bases. 
     
     
         6 . The method for obtaining copper nanoparticles according to  claims 1  to  5 , wherein the defoamer of step vi) is selected from high molar weight alcohols such as hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol and its branched derivatives; wherein also the defoamer is selected from aromatic alcohols, and any defoamer for water-based systems such as defoamers based on polysiloxanes, based on mineral oil, based on vegetable oil, and based on polymers. 
     
     
         7 . The method for obtaining copper nanoparticles according to  claims 1  to  6 , wherein the reducer of step vii) is selected from hydrazine monohydrate and its derivatives; hydroxylamine and its derivatives; monohydric alcohols such as methanol, ethanol; aldehydes such as formaldehyde, ammonium formate, acetaldehyde and propane aldehyde or salts thereof;
 hypophosphites, sulfites, tetrahydroborates, lithium tetraaluminohydride (LiAlH 4 ), sodium borohydride, polyhydroxybenzene such as hydroquinone and its derivatives, phenylenediamines and their derivatives, aminophenols and their derivatives, carboxylic acids and their derivatives such as ascorbic acid and citric acid. 
 
     
     
         8 . The method for obtaining copper nanoparticles according to  claims 1  to  7 , wherein the antioxidant of step ix) is selected from carboxylic acids and their derivatives such as ascorbic acid, citric acid, hydrazine monohydrate and derivatives, hydroxylamine and its derivatives, monohydric alcohols such as methanol, ethanol, aldehydes such as formaldehyde, ammonium formate, acetaldehyde and propanoaldehyde or salts thereof, hypophosphites. 
     
     
         9 . The method for obtaining copper nanoparticles according to  claims 1  to  8 , wherein the secondary complexer x) is selected from carboxylic acids and their derivatives, dicarboxylic acids, unsaturated carboxylic acids, ammonia (NH 3 ), hydroxide ammonium, primary and secondary amines. 
     
     
         10 . The method for obtaining copper nanoparticles according to  claim 9 , wherein the carboxylic acids and their derivatives are selected from ascorbic acid, citric acid, aliphatic and aromatic carboxylic acids. 
     
     
         11 . The method for obtaining copper nanoparticles according to  claim 10 , wherein the aliphatic and aromatic carboxylic acids are selected from benzoic acid and phenylacetic acid. 
     
     
         12 . The method for obtaining copper nanoparticles according to  claim 9 , wherein the dicarboxylic acids are selected from ethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, octanedioic acid, nonadioic acid, decadioic acid, butenodioic acid, phthalic acid, 2,4-diphenylcyclobutan-1,3-dicarboxylic acid, 3,4-diphenylcyclobutane-1,2-dicarboxylic acid. 
     
     
         13 . The method for obtaining copper nanoparticles according to  claim 9 , wherein the primary and secondary amines are selected from isopropylamine, butylamine, pentylamine, hexylamine, heptylamine and octylamine. 
     
     
         14 . The method for obtaining copper nanoparticles according to  claims 1  to  13 , wherein the solvent of step xii) is selected from water, preferably deionized, and monoprotic solvents such as methanol, ethanol, isopropanol, acetone. 
     
     
         15 . The method for obtaining copper nanoparticles according to  claim 1 , wherein in step v) the pH must be adjusted to a value between 5 and 12.5. 
     
     
         16 . The method for obtaining copper nanoparticles according to  claim 1 , wherein a secondary polymer or a modifying molecule is added in any of the steps i), iii), iv), v), vi), vii), x), xi) and xii), wherein the secondary polymer is selected from the group of polymers such as poly (vinylpyrrolidone) (PVP), polyvinyl alcohol, polycarbonates, polyphenols, polyethylene glycol and polyols such as ethylene glycol, diethylene glycol, tri-ethylene glycol, propylene glycols, alkyldiols such as butanediols, dipropylene glycol and polyethylene glycols, chitosan and its derivatives, polyacids and derivatives thereof, mercaptoalkanoates, and oxybenzoic acids; wherein the polyacids include one or more of those selected from the group of poly (acrylic acid), poly (maleic acid), poly (methyl methacrylate),poly (acrylic acid-co-methacrylic acid), poly (maleic acid-co-acrylic acid), and poly (acrylamide-coacrylic acid), cellulose acetates, polyvinylacetates, polysulfones, polyphenylsulphones, potassium sulfones, polyketones, polyetherketones, polyesters and their derivatives, including one or more of those selected from the group of ammonium, sodium or potassium salts of the polyacids and inorganic polymers of the phosphazene type and wherein a modifying molecule is selected from the group of aliphatic and/or aromatic molecules, with  2  or more carbon atoms, which may include oxygen, nitrogen, sulfur, phosphorus or mixture thereof, with one or more functional groups, which may also be organometallic complexes, clusters or mixtures of atoms, homo- and heteronuclear functional groups. 
     
     
         17 . Copper nanoparticles obtained according to the method described in  claims 1  to  16 , wherein they comprise a size between 10 nm and 200 nm, and show a UV-Vis spectrum with a plasmon moving from 579 nm to 595 nm. 
     
     
         18 . Use of the copper nanoparticles obtained according to the method described in  claims 1  to  16 , wherein it serves to prepare polymer membranes.