Silicon Nanoparticles을 이용한 폭발물의 탐지

Abstract

Synthesis and characterization of alkyl-capped nanocrystalline silicon (R-n-Si) have been achieved from the reaction of silicontetrachloride with magnesiumsilicide. Surface of silicon nanocrystal has been derivatized with various alkyl groups (R=methyl, n-butyl, etc.). Silicon nanoparticles have been also obtained by the sonication of luminescent porous silicon. Former exhibits an emission band at 360 nm, but latter exhibits an emission band at 680 nm. Over the past decade there has been considerable interest in semiconductor nanoparticles for their interesting properties resulting from the confinement of carriers in all three dimensions and for their possible applications in electronics, optics, and sensors such as a diode lasers. Semiconductor nanoparticles, or quantum dots, represent mesoscopic materials which have physical properties between bulk materials and molecular compounds. Synthetic routes of II-VI semiconductor nanoclusters, providing control over the size and the surface termination are well-developed. Alivisatos' group derivatized the surface ofcore-shell nanoparticles, CdSe-CdS, for the use of biosensors. They showed that these nanoparticles are good candidates as fluorescent biological labels for biosensors, but there are still unsolved problems converning on the hazards issues in the biological system because of the requisite heavy metal element. For this reason silicon nanoparticles would be an excellent alternative, since they are biocompatible. However there has been little advancement both in synthetic methods for the production of group IV nanoparticles and in their uses for biosensors and biocompatible materials. Also detection of nitroaromatic compounds is desirable since there are approximately 120 million unexploded land mines worldwide. Detection of nitroaromatic compound based on adsorption into polymers has been reported. Chemo-selective polymers on SAW(surface acoustic wave) device, cyclic voltammetry using gold micro-electrode covered with non-volatile electrolyte, and organic polymer has been previously reported to detect TNT vapor. In this study very sensitive detection of TNT (2,4,6-trinitrotoluene), DNT (2,4-dinitrotoluene), NB (nitrobenzene), and PA (picric acid) has been achieved in gas phase with porous silicon using photoluminescence quenching of the silicon crystallites as a trans- duction mode. Porous silicon are electrochemically etched from crystalline silicon wafers in an aqueous solution of hydrofluoric acid. We have characterized these silicon nanoparticles by Luminescence Spectrometer (LS 55)