| 초록 |
We report a new methodology to functionalize nanoporous silica using an amphiphilic organotriethoxysilane designed to integrate an affinity for nanoparticles into the nanoporous silica structure. The amphiphilic silane, TEGNE-phenol-Si, was synthesized. This compound contained a nonyl aliphatic chain, a tetra(ethylene glycol) spacer, a thermally reversible urethane moiety, and a reactive triethoxysilyl group. It dissociated to produce isocyanate functionality upon heating. Nanoporous silica (NPS) materials with a pore size of average diameter in the range of 10 nm were fabricated by co-condensation of a mixture of TEGNE-phenol-Si and tetraethylorthosilicate (TEOS). The thiol functionalized nanoporous silica (TNPS) materials were prepared by heating NPS to 130 ℃ in DMF in the presence of 1,9-nonanedithiol. In this process, the thiol was reacted with the dissociated isocyanato group tethered to the pore wall. CdSe nanoparticles were encapsulated in TNPS by adding a dichloromethane solution of spherical tri-n-octylphosphine oxide (TOPO)-covered CdSe nanoparticles of 3 nm diameter to the suspension of TNPS in methylene chloride. CdSe nanoparticles were found in the pores of TNPS in a well-dispersed fashion by transmission electron microscopy, indicating that the thiol groups within the nanoporous structure effectively passivated the nanoparticle surface, so as to displace TOPO from the surface and concomitantly entrap the nanoparticles. |
