Porous Substrates, Articles, Systems and Compositions Comprising Nanofibers and Methods of Their Use and Production

Abstract

Porous and/or curved nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, production of long unbranched nanofibers, and the like. A method of producing nanofibers is disclosed including providing a plurality of microparticles or nanoparticles such as carbon black particles having a catalyst material deposited thereon, and synthesizing a plurality of nanofibers from the catalyst material on the microparticles or nanoparticles. Compositions including carbon black particles having nanowires deposited thereon are further disclosed.

1 . A method of producing nanofibers, the method comprising:
 providing a substrate comprising a plurality of microparticles, glass or quartz fibers, or nanoparticles, each having a catalyst material deposited thereon; and   synthesizing a plurality of nanofibers from the catalyst material on the microparticles, glass or quartz fibers, or nanoparticles.   
     
     
         2 . The method of  claim 1 , wherein the nanofibers comprise nanowires. 
     
     
         3 . The method of  claim 2 , wherein synthesizing the plurality of nanowires comprises:
 depositing a gold colloid on at least a portion of the overall surface area of the substrate; and   growing the nanowires from the gold colloid with a VLS synthesis technique.   
     
     
         4 . The method of  claim 1 , wherein the substrate comprises carbon black particles. 
     
     
         5 . The method of  claim 1 , wherein the substrate comprises glass or quartz microspheres. 
     
     
         6 . The method of  claim 1 , wherein the plurality of nanofibers comprises a semiconductor material selected from group IV, group II-VI and group III-V semiconductors. 
     
     
         7 . The method of  claim 1 , wherein the plurality of nanofibers comprise silicon or silicon oxide. 
     
     
         8 . The method of  claim 1 , further comprising removing the synthesized nanofibers from the surface of the substrate, following synthesis of the nanofibers, to produce a population of detached nanofibers. 
     
     
         9 . The method of  claim 8 , wherein said removing comprises heating the substrate to remove the nanofibers. 
     
     
         10 . The method of  claim 9 , wherein said heating comprises heating the substrate to a temperature greater than about 500 degrees Celsius. 
     
     
         11 . The method of  claim 1 , wherein the substrate comprises carbon particles. 
     
     
         12 . The method of  claim 1 , wherein the substrate is free of attachment to another solid support. 
     
     
         13 . The method of  claim 1 , wherein the substrate comprises a powder. 
     
     
         14 . The method of  claim 11 , wherein one or more surfaces of the carbon particles are curved. 
     
     
         15 . The method of  claim 1 , wherein the substrate comprises microspheres, spherical glass or quartz fibers, or spherical nanoparticles. 
     
     
         16 . The method of  claim 1 , wherein the substrate comprises glass fibers. 
     
     
         17 . The method of  claim 1 , wherein the substrate comprises quartz fibers. 
     
     
         18 . The method of  claim 1 , wherein the substrate comprises glass microfibers. 
     
     
         19 . The method of  claim 1 , wherein the substrate comprises quartz microfibers. 
     
     
         20 . The method of  claim 1 , wherein the substrate comprises fiberglass. 
     
     
         21 . The method of  claim 1 , wherein the substrate comprises microspheres.