Photoluminescence response of terbium-exchanged MFI-type materials to Si/Al ratio, texture and hydration state

Article Abstract:

Terbium-exchanged MFI zeolite type materials, microporous-mesoporous Zeolite-1 with the Si/Al ratio in the range of 33-200, Zeogrid with the Si/Al ratio of 75 and nanocrystalline MFI with Si/Al ratio 75 were prepared via an ion exchange procedure and investigated by time resolved photoluminescence techniques. The results show that, in Zeolite 1 and Zeogrid, two distinct locations of [Tb.sup.3+] exist which might correlate with two types of exchange sites, one on the internal surface of mesopores, the other inside the pores while for MFI, the site predominate inside the pores.

Terbium

---

Time-resolved photoluminescence characteristics of subnanometer ZnO clusters confined in the micropores of zeolites

Article Abstract:

Subnanometric ZnO clusters confined in different micropore zeolites are studied by photoluminescence (PL) spectroscopy. The results show that the subnanometric ZnO clusters display significantly different optical behaviors from macrocrystalline ZnO, mainly due to the quantum confinement effect. The dependence of luminescence lifetime on the amount of ZnO in zeolites indicates that the electron-photon interactions between the ZnO clusters and the zeolite host significantly affect the dynamic relaxation process of ZnO clusters.

Zeolites, Quantum chemistry, Zinc oxide

---

Water exclusion at the nanometer scale provides long-term passivation of silicon (111) grafted with alkyl monolayers

Article Abstract:

Si(111)-alkyl layer interfaces are prepared with a very low density of electronic traps after careful control of the grafting conditions. Water exclusion from the monolayer has promoted long-term passivation of the silicon surface against oxidation in air and water as well as perfect corrosion inhibition in 20% NH4F.

Monomolecular films, Alkyl groups

Similar abstracts:

• Abstracts: Nonlinear response of a batch BZ oscillator to the addition of the anionic surfactant sodium dodecyl sulfate. Thermotropic phase behavior of cationic gemini surfactants and their equicharge mixtures with sodium dodecyl sulfate
• Abstracts: Two-photon fluorescence spectroscopy of individually trapped pseudoisocyanine J-aggregates in aqueous solution
• Abstracts: Decomposition of methane over a Ni-Cu-MgO catalyst to produce hydrogen and carbon nanofibers. High-temperature Raman spectroscopy of solid oxide fuel cells materials and processes
• Abstracts: Molecular dynamics of apo-adenylate kinase: A distance replica exchange method for the free energy of conformational fluctuations
• Abstracts: Infrared spectroscopy of competitive interactions between liquid crystals, metal salts, and dimethyl methylphosphonate at surfaces

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.