Blue-green luminescent (2.48-3.10 eV) alkyl-passivated silicon nanoparticles (Si NPs) were synthesized in a single step, facile procedure by high energy ball milling single crystal silicon (1 00) wafer in the presence of reactive 1-hexyne (C6H10). The subsequent fractionation process allows for the efficient recovery of excess alkyne, purification, and separation of 1-hexyne terminated silicon nanoparticles. This preparative column procedure isolates Si NPs with predominantly nonpolar surfaces as confirmed by FTIR. Samples exhibit photoluminescence emission energies of 2.46 eV for the retained fractions and 2.95 eV for eluted fractions, illustrating a dependence on the polarity of surface passivations. (C) 2011 Elsevier B.V. All rights reserved.