2010, №2

сс. 79-90

Immobilization of Luminescent Nanosilicon in the Microfine Polytetrafluoroethylene Matrix by Supercritical Carbon Dioxide

2010, №2

сс. 79-90

Цитировать

V.N. Bagratashvili, S.G. Dorofeev, A.A. Ischenko, V.V. Koltashev, N.N. Kononov, A.A. Krutikova, A.O. Rybaltovskii, G.V. Fetisov

Key words: polymer nanocomposite, supercritical fluid impregnation, nanocrystalline silicon, photoluminescence

With  the use of supercritical carbon dioxide (SC-СO2) a process of matrix  immobilization of photoluminescent silicon nanocrystals (nc-Si) in  polytetrafluoroethylene microparticles (mp-PTFE) is implemented, which leads to  the formation of photoluminescent nanocomposite mp-PTFE/nc-Si containing ~103 ÷104 of nc-Si in one PTFE particle (1—2 microns in size). This  process is based on the effect of polymer swelling in SC-СO2,  efficient transport of nanoparticles into internal free volume of polymer with  SC-СO2, and shrinkage of nanocomposite after the release of СO2   thus preventing their subsequent agglutination. Particles of nc-Si  photoluminescent in the visible spectrum range were synthesized from silicon  suboxide powder (SiOx, x ~ 1)  heated at temperatures from 25 °C to 950 °C and next etched in concentrated  hydrofluoric acid. The hydrosilylation procedure was used to attach  1-octadecene molecules to the surface of nc-Si. As a result, the  photoluminescence intensity of nc-Si increased substantially. According to TEM  images and small angle X-ray diffraction results, the maximum size of nc-Si  particles did not exceed 5 nm and 7 nm respectively, and the core of these  nanoparticles consisted of crystalline silicon. The structure and spectral  properties of the initial nc-Si particles and synthesized photoluminescent  nanocomposite mp-PTFE/nc-Si microparticles were studied.

doi:10.1134/S1990793110070171