Polysilole Nanoaggegate 와 Polysilole-SiO2 colloids를 이용한 폭발물질 탐지에 관한 연구.

Abstract

In recent years, photoluminescence polysilole has been a topic of interest because of ther unusual electrical and optical properties. It is also reported that silole-containing polymers are selective chemosensors for nitroarematec oxidants,including TNT.¹-² Detection has been achieved though fluorescence quenching of the silole by the electron-deficient analyte. The luminescence of silole is due to a σ*-π* LUMO stabilized though conjugation of the σ* orbital of the silicon chain with the π* orbital of the butadiene moiety³. The selectivity of the sensor is due to the helical structure of polymer, which permits the intercalation of planar nitroaromatics³-⁴. Recently,it has been reported that colloidal suspensions of methylphenysilole may be prepared by the rapid addition of water to an ethanolic silole solution and characterized5. As most nanopartcles characterized in the literature are either purely inoganic6-7, such as semiconductor quantum dots6, or purely organic (e.g.,carotenes8 and dendrimers9),the silole organometallic nanoparticles are of particular interest for their unipue photophysical and structural properties, as well as their sensor application.6 Fluorescent inoganic quantum dots have been shown to be wildely useful in sensing applications.10,11 This paper describes the potential utility of luminescent polysilole nanoaggregate in sensing applications. The aggregation of highly emissive organics and polymers into a solid state causes an emission-quenching effect, since the aggregation of molecules forms less emissive species such as eximers.12-13 Reduction of emission efficiency in solid state has been a major problem in device applications of light-emitting organic molecules. Many attempst to prevent aggregate formation have been done through chemical, physical, and engineering approaches. In contrast, few results on aggregateio-induced emission(AIE) properties have been recently reported. For silole solution in pure THF, the photoluminesecene(PL)intensity is very weak and the emission peak near 520nm was observed.7 As increasing water fraction, the emission intensity of polysilole aggregates increases dramatically. An attractive feature of these molecular based materials is a great sensitivity for the nitroaromatics.9 As Polysilole aggregates are synthesized with TMOS(tetramethoxy orthosilicate), Polysilole/SiO₂ aggregates composed polysilole intercalated into a porous silicate network have been synthesized. This polysilole/SiO₂ aggregates exhibit similar photoluminescence intensity compared to polysilole aggregates, but display greater sensitivity than polysilole aggregates for the nitroaromatics.