Determination of room-temperature fluorescence and phosphorescence quantum yields for compounds adsorbed on solid surfaces

Synthesis of Yb3+/Er3+ co‐dopants sodium yttrium fluoride up‐conversion fluorescence materials

“…The synthesized NaYF 4 :Yb and a sample synthesized by other methods were compared for up-conversion efficiency, using the method suggested by Ramasamy (17). The results indicated that the up-conversion efficiency of the red fluorescence of the synthesized sample of rare-earth-doped sodium yttrium fluoride (wavelengths 520 nm and 539 nm) is around 25%, which was much higher than the results in the literature.…”

Fluorescence of Cereal Flours

“…Fluorescence from solutions has had a long and rich history in biological sciences. On the contrary, surface emissions from solids, in particular from noncrystalline solids, have been scarcely studied (Wrighton et al, 1974;Ramasamy et al, 1986). Reflectance and thermal emittance spectroscopies of surfaces of particulate materials have had many applications in the field of remote sensing and imaging (Hapke, 1993a), meanwhile epifluorescence has had an explosive development in the field of fluorescence microscopy applied to biological and medical sciences.…”

Room-temperature luminescence properties of p-aminobenzoic acid adsorbed on sodium acetate-sodium chloride mixtures

“…The NaOAc/NaCI mixtures were prepared by grinding them in a ball mill for 1 h and storing them in a desiccator prior to use. The details of other reagents, purification of nitrogen gas, cell compartment, sample holders, temperature monitoring, and cryogenic system were described previously (5,12).…”

“…Sample Preparation. Powdered samples of NaOAc (standard blank), sodium salicylate/NaOAc (1 mg/150 mg) (standard), PABA/NaOAc-NaCl (1.5 /xg/100 mg) (phosphor), and NaOAc-NaCl (phosphor blank) were prepared as reported earlier (12). The oven-dried samples were ground into homogeneous powder in a stainless steel ball mill for 5 min and dried again at 80 °C for 10 min.…”