Ceramic-polymer hybrid nanostructures, methods for producing and applications thereof

Abstract

Provided herein are methods for forming nanofibers. The current disclosure provides ceramic nanofibers, morphology-controlled ceramic-polymer hybrid nanofibers, morphology-controlled ceramic nanofibers, core-sheath nanofibers and hollow core nanofibers using ceramic precursor materials and polymer materials which are combined and undergo electrospinning. The current disclosure provides for methods of forming these nanofibers at low temperatures such as room temperature and in the presence of oxygen and moisture wherein the ceramic precursor cures to a ceramic material during the electrospinning process. Also disclosed are the nanofibers prepared by the disclosed methods.

We claim: 
     
         1 . A method for forming a ceramic-polymer hybrid nanofiber comprising the steps of:
 a. providing a fluid stock comprising precursor material and a polymer;   b. electrospinning the fluid stock onto a substrate; and   c. exposing the electrospun product to oxygen, water and an optional catalyst during spinning and/or following collection on the substrate,   
       wherein the precursor material is selected from the group consisting of perhydropolysilazane, organopolysilazane, and combinations thereof; and 
       wherein the ceramic-polymer hybrid nanofiber comprises polymer and a ceramic. 
     
     
         2 . The method of  claim 1 , wherein within one hour of being exposed to oxygen, water and an optional catalyst, the electrospun product is a cured ceramic polymer hybrid nanofiber. 
     
     
         3 . The method of  claim 1 , wherein the fluid stock further comprises a catalyst. 
     
     
         4 . The method of  claim 3 , where the catalyst is an amine. 
     
     
         5 . The method of  claim 1 , wherein the temperature of electrospinning is about 300° C. or below. 
     
     
         6 . The method of  claim 5 , wherein the process of electrospinning is performed at 50° C. or below. 
     
     
         7 . The method of  claim 5 , wherein the method is performed without further thermal treatment. 
     
     
         8 . The method of  claim 1 , wherein the degree of curing to a ceramic of the precursor material after electrospinning is above about 75%. 
     
     
         9 . The method of  claim 7 , wherein the degree of curing to a ceramic of the precursor material after electrospinning is above about 75%. 
     
     
         10 . The method of  claim 1 , wherein the process of electrospinning the fluid stock is gas assisted. 
     
     
         11 . The method of  claim 1 , wherein the polymer material is at least one material chosen from the group consisting of poly(ethylene oxide), polyamide resins, aramid resins, poly(meta-phenyleneisophthalamide), polyalkylene oxides, polyolefins, polyethylenes, polypropylenes, polyethyleneterephthalates, polyurethanes, rosin ester resins, acrylic resins, polyacrylate resins, polyacrylamides, polyvinyl alcohols, polyvinyl acetates, polyvinyl ethers, polyvinylpyrollidones, polyvinylpyridines, polyisoprenes, polylactic acids, polyvinyl butyral resins, polyesters, phenolic resins, polyimides, vinyl resins, ethylene vinyl acetate resins, polystyrene/acrylates, cellulose ethers, hydroxyethyl cellulose, ethyl cellulose, cellulose nitrate resins, polymaleic anhydrides, acetal polymers, polystyrene/butadienes, polystyrene/methacrylates, aldehyde resins, polyacrylonitriles, cellulosic polymers, polyketone resins, polyfluorinated resins, polyvinylidene fluoride resins, polyvinyl chlorides, polybenzimidazoles, poly vinyl acetates, polyethylene imides, polyethylene succinates, polyethylene sulphides, polyisocyanates, SBS copolymers, polyglycolic acid, polypeptides, proteins, epoxy resins, polycarbonate resins, coal-tar pitch petroleum pitch and combinations thereof. 
     
     
         12 . The method of  claim 1 , wherein the fluid stock comprises a weight ratio of precursor to polymer about 1:99 or more. 
     
     
         13 . The method of  claim 12 , wherein the fluid stock comprises a weight ratio of precursor to polymer of about 15:35 to about 15:50. 
     
     
         14 . A nanofiber comprising a combination of (i) polymer, (ii) ceramic, and (iii) perhydropolysilazane, organopolysilazane, or a combination thereof. 
     
     
         15 . The nanofiber of  claim 14 , wherein the nanofiber comprises a matrix with domains embedded therein, the matrix comprising the polymer and the domains comprising (i) the ceramic and (ii) the perhydropolysilazane, the organopolysilazane, or a combination thereof. 
     
     
         16 . The nanofiber of  claim 14 , wherein the nanofiber comprises about 60 wt % to about 97 wt % polymer. 
     
     
         17 . The nanofiber of  claim 14 , wherein the nanofiber comprises about 3 wt % to about 40 wt % ceramic. 
     
     
         18 . The nanofiber of  claim 16 , wherein the nanofiber comprises about 3 wt % to about 40 wt % ceramic. 
     
     
         19 . The nanofiber of  claim 18 , wherein the nanofiber comprises less than 5 wt % of perhydropolysilazane, organopolysilazane, or a combination thereof. 
     
     
         20 . The nanofiber of  claim 14  wherein the ceramic comprises cured perhydropolysilazane and/or cured organopolysilazane. 
     
     
         21 . A battery comprising an anode, a cathode, and a separator, the separator separating the anode from the cathode and comprising one or more nanofiber(s), the one or more nanofiber(s) comprising a matrix with discrete domains embedded within the matrix, the matrix comprising polymer and the discrete domains comprising ceramic. 
     
     
         22 . The battery of  claim 20  wherein the ceramic comprises cured perhydropolysilazane and/or cured organopolysilazane. 
     
     
         23 . The battery of  claim 20  wherein the separator undergoes a volume shrinkage of less than 5% when heated to a temperature below 300° C. 
     
     
         24 . The battery of  claim 20  wherein the battery is a lithium ion battery. 
     
     
         25 . The battery of  claim 20 , wherein the one or more nanofiber(s) comprise about 60 wt % to about 97 wt % polymer, and about 3 wt % to about 40 wt % ceramic.