Study of persistent luminescent materials containing rare earth ions in hydrophobic substrates

• Grant number: 15/08432-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2015
• End date: May 31, 2016
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Hermi Felinto de Brito
• Grantee: Luís Fernando Matheus Zambon
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The luminescent materials MAl2O4:Eu2+,TR3+ (M = Ca, Sr, Ba), (TR = Nd3+,Dy3+) belongs to the class of the alkaline earths aluminates doped with rare earth ions, they present persistent luminescent properties, emitting light for several hours after removed the excitation source. This phosphors display low chemical stability when in contact with water. It results in the total suppression of persistent luminescence and this factor prevent their industrial applications. Therefore, the objective of this work is to study the phosphors coating with 2 highly waterproof materials: The polymer PMMA(Polymethylmethacrylate), and the wax AKD (Alkyl Ketene Dimmer),the waterproof materials will act protecting the phosphours from the water contact preserving its photoluminescent properties. The materials will be characterized by the following techniques: X ray Diffraction (powder method), Thermal analysis (TG/DTG), Infrared Vibrational spectroscopy, Electronic microscopy (MEV) and electron transmission microscopy (TEM). This analysis will yield structural, thermal and optical information. The phosphors covered with hydrophobics compounds will have its photoluminescent properties studied using excitation, emission and thermoluminescent spectra. When comparing the data of the phosphors with and without the covering with PMMA and AKD will be possible evaluate the changes occurred by the coating with the hydrophobic materials. (AU)