Process for making silver nanostructures and copolymer useful in such process

Abstract

A process for making silver nanostructures, which includes the step of reacting at least one polyol and at least one silver compound that is capable of producing silver metal when reduced, in the presence of: (a) a source of chloride or bromide ions, and (b) at least one copolymer that comprises: (i) one or more first constitutional repeating units that each independently comprise at least one pendant saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety per constitutional repeating unit, and (ii) one or more second constitutional repeating units, each of which independently differs from the one or more first nonionic constitutional repeating units, and has a molecular weight of greater than or equal to about 500 grams per mole, is described herein.

What is claimed is: 
     
         1 . Silver nanostructures made by the process comprising: reacting at least one polyol and at least one silver compound that is capable of producing silver metal when reduced, in the presence of:
 (a) a source of chloride or bromide ions, and   (b) at least one copolymer that comprises:
 (i) one or more first constitutional repeating units that each independently comprise at least one pendant saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety per first constitutional repeating unit, and 
 (ii) one or more second constitutional repeating units, each of which independently differs from the one or more first constitutional repeating units, the second constitutional repeating unit comprising at least one pendant cationic moiety that comprises a quaternary ammonium nitrogen atom and a nitrate counter anion, 
 and has a molecular weight of greater than or equal to about 500 grams per mole. 
   
     
     
         2 . A copolymer, comprising, based on 1000 constitutional repeating units of the copolymer:
 from 800 to 999 first constitutional repeating units, each independently comprising at least one pendant saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety per constitutional repeating unit, and   from 1 to 200 second constitutional repeating units, each independently comprising at least one pendant organic moiety per unit that: (i) is selected from ionic organic moieties and nonionic organic moieties, and (ii) is not a saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety,   
       and having a molecular weight of greater than or equal to about 500 grams per mole. 
     
     
         3 . The copolymer of  claim 2 , wherein the second repeating units each independently comprise at least one pendant organic moiety per unit that is selected from cationic organic moieties. 
     
     
         4 . The copolymer of  claim 3 , wherein, the copolymer is a random copolymer made by free radical polymerization of vinyl pyrrolidone, vinyl caprolactam, or vinyl pyrrolidone and vinyl caprolactam with one or more ethylenically unsaturated cationic monomers. 
     
     
         5 . The copolymer of  claim 4 , wherein the one or more ethylenically unsaturated cationic monomers are selected from dimethylaminomethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, di(t-butyl)aminoethyl (meth)acrylate, dimethylaminomethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, vinylamine, vinyl imidazole, vinylpyridine, vinylpyrrolidine, vinylpyrroline, vinylpyrazolidine, vinylpyrazoline, vinylpiperidine, vinylpiperazine, vinylpyridine, vinylpyrazine, vinylpyrimadine, vinylpyridazine, trimethylammonium ethyl (meth)acrylate salts, dimethylammonium ethyl (meth)acrylate salts, dimethylbenzylammonium (meth)acrylate salts, benzoylbenzyl dimethylammonium ethyl(meth) acrylate salts, trimethyl ammonium ethyl (meth)acrylamido salts, trimethyl ammonium propyl (meth)acrylamido salts, vinylbenzyl trimethyl ammonium salts, and diallyldimethyl ammonium salts. 
     
     
         6 . The copolymer of  claim 4 , wherein the copolymer is a random copolymer made by free radical polymerization of a monomer mixture comprising from about 800 to less than 1000 parts by weight of vinyl pyrrolidone and from greater than 0 to about 200 parts by weigh of a diallyldimethylammonium salt.