Preparation, characterization and mechanical properties of rare-earth-based nanocomposites

Abstract

This study reports research related to different preparation methods and characterization of polymer nanocomposites for optical applications. The Eu-ion doped Gd2O3 nanophosphor powder with different nanoparticle content was embedded in the matrix of PMMA. Preparation was carried out by mixing molding (bulk), electrospinning (nanofibers) and solution casting (thin films) with neat particles and particles coated with AMEO silane. Among the pros and cons for proposed methods, the mixing molding enables to avoid solvent use while the best deagglomeration and nanoparticle distribution is gained using the electrospinning method. The results of dynamic mechanical analysis (DMA) and nanoindentation revealed that the storage modulus of the composites was higher than that of pure PMMA and increased with nanophosphor content. Surface modification of particles improved the mechanical properties of nanocomposites

Electrospinning of laser dye Rhodamine B-doped poly(methyl methacrylate) nanofibers

“…This is correlated to the viscosity/polarity-dependent behavior of RhB molecules in the solvent. [39][40][41] This is also in accord with the determined viscosity of the solutions with different concentrations of RhB. Having smaller dye-dye molecular distances, RhB in DMF permitted the formation of aggregates that were responsible for the reduction of the T g of the fibers with higher contents of RhB.…”

Synthesis, characterization, luminescence properties and thermal studies of polyaniline and polythiophene composites with rare earth terbium(III) complex

“…M-N and M-O stretching vibrations are observed at 725 cm À1 and 612 cm À1 , respectively [29,30]. Presence of nitrate ion is confirmed by a peak at 1076 cm À1 that match well with the results of available literature [31,32]. Peak at 773 cm À1 shows the presence of 2,2 0 -bipyridyl which corresponds to the skeleton vibration of aromatic heterocyclic ring containing nitrogen [33].…”

Indentation behaviour of 'soft film on hard substrate' composite system type

“…Microhardness values are always below their nanoindentation hardness values, even the two kinds of hardness exibit similar load effect, owing to the indentation size effect (ISE) [16][17][18].…”