Mechanochemically Functionalized Silicon

Abstract

The mechanochemical functionalization of silicon nanoparticles and functionalized silicon nanoparticles are described. The processes include applying shear forces to silicon metal the presence of an alkane and thereby functionalizing the silicon with an alkyl-functionalization, preferably an alkyl-hydride-functionalization. The resulting product includes a plurality of silicon nanoparticles each carrying an alkyl-functionalization, and preferably a hydride-functionalization, derived from an alkane.

1 . A material comprising:
 functionalized silicon nanoparticles made by a process that includes:   shearing a silicon metal or alloy in the presence of a liquid alkane and/or liquid hetero-alkane by applying shear forces to the silicon metal to expose a sheared silicon surface,   forming alkyl functionalities and hydride functionalities on the sheared silicon surface; and   continuing to shear the silicon metal or alloy in the presence of the alkane and/or hetero-alkane until the silicon metal is reduced to a plurality of functionalized silicon nanoparticles.   
     
     
         2 . The material of  claim 1 , wherein shearing the silicon metal or alloy exposes silicon radicals on the sheared silicon surface, the process then including reacting the silicon radicals with the alkane and/or hetero-alkane to provide the alkyl-functionalization. 
     
     
         3 . The material of  claim 1 , wherein the silicon metal or alloy includes greater than about 90 wt. % silicon. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . A functionalized silicon nanoparticle comprising:
 a silicon nanoparticulate that is composed of silicon or a silicon alloy, the silicon nanoparticulate having a plurality of surfaces; the surfaces comprising silicon atoms;   the silicon atoms carrying hydride functionalities and alkyl and/or heteroalkyl functionalities   the alky functionalities derived from an alkane having about 4 to about 25 carbon atoms;   the heteroalkyl functionalities derived from a heteroalkane having about 3 to about 80 carbon atoms; and   wherein the heteroalkyl and the heteroalkane include a heteroatom selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorous atom, a fluorine atom, a chlorine atom, a boron atom, and a combination thereof.   
     
     
         7 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon atoms are affixed by sigma bonds to the alkyl or heteroalkyl functionalities. 
     
     
         8 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon atoms are affixed by sigma bonds to the hydride functionalities. 
     
     
         9 . The functionalized silicon nanoparticle of  claim 6 , wherein the plurality of surfaces include surfaces having Miller index other than (111) and (100). 
     
     
         10 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon nanoparticulate has a morphology other than spherical. 
     
     
         11 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon nanoparticulate is plate-like. 
     
     
         12 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon nanoparticulate is polycrystalline. 
     
     
         13 . The functionalized silicon nanoparticle of  claim 6  further comprising a mean diameter in the range of about 20 nm to about 500 nm. 
     
     
         14 . The functionalized silicon nanoparticle of  claim 13 , wherein the mean diameter is in the range of about 50 nm to about 300 nm. 
     
     
         15 . The functionalized silicon nanoparticle of  claim 6 , wherein the silicon atoms carry hydride and alkyl functionalities derived from an alkane; wherein the silicon atoms are affixed by sigma bonds to the alkyl functionalities and to the hydride functionalities. 
     
     
         16 . The functionalized silicon nanoparticle of  claim 15 , wherein the silicon nanoparticulate is polycrystalline. 
     
     
         17 . A polycrystalline silicon nanoparticle comprising:
 a polycrystalline silicon nanoparticulate that is composed of silicon or a silicon alloy, the silicon nanoparticulate having a plurality of surfaces; the surfaces comprising silicon atoms;   the silicon atoms affixed, by Si to H sigma bonds, to hydride functionalities and affixed, by Si to C sigma bonds, to alkyl and/or heteroalkyl functionalities;   wherein the alky functionalities individually include about 4 to about 25 carbon atoms;   wherein the heteroalkyl functionalities individually include about 3 to about 80 carbon atoms, and include a heteroatom selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorous atom, a fluorine atom, a chlorine atom, a boron atom, and a combination thereof.   
     
     
         18 . The polycrystalline silicon nanoparticle of  claim 17 , wherein the silicon alloy includes greater than about 90 wt. % silicon.