Analysis of photoluminescent chromophores obtained from a cellulose acetate and silica sphere composite

作者：Kimx Byoung Ju; Kang So Yeon; Kim Do Kyoon; Moon Sang Hyun; Park Eun Hye; Kang Kwang Sun^*

来源：Journal of Non-Crystalline Solids, 2015, 412: 45-48.

DOI：10.1016/j.jnoncrysol.2014.12.037

• Silica sphere
• Composite
• Photoluminescence
• Acetone

Photoluminescent chromophores obtained from cellulose acetate (CA) and silica sphere composites have been analyzed with field emission scanning electron microscope (FESEM), energy dispersive spectroscope (EDS) and photoluminescence (PL) spectroscope. Acetone was used as a solvent. Two different amounts of silica spheres (0.07 and 0.14 g) were mixed in 4.0 g of the CA solution and called SCA-A and SCA-B, respectively. According to the FESEM images, after soaking silica spheres in CA solution for 6 months, both SCA-A and SCA-B have large number of nanocracks on the surface of the spheres. The chromophores (SCA-A and SCA-B) are comprised of carbon (692 and 65.1 wt%), nitrogen (8.8 and 103 wt.%), oxygen (20.8 and 12.4 wt.%), and silicon (1.2 and 12.2 wt.%), respectively. Although there is no nitrogen source, a significant amount of nitrogen was detected by EDS. The nitrogen could have originated from the trapped or reacted ammonia during the Stober process. The amount of silicon significantly increased with the increase of silica spheres. There were three characteristic PL peaks at 2.76 eV (450 nm), 2.49 eV (497 nm), and 233 eV (530 nm), which were caused the luminescence peak shift with different excitation wavelengths. The luminescence peak reduced with the increase of the radiation time for SCA-A. However, the luminescence peak slightly increased with the increase of the radiation time. This result implies that the SCA-A chromophore is unstable or intermediate state to become SCA-B.

• 出版日期2015-3-15