Study on UV Excitation Properties of Y₂O₃:Ln³⁺ (Ln = Eu³⁺ or Tb³⁺) Luminescent Nanomaterials

Abstract

Y2O3:Ln3+ (Ln = Eu or Tb) nanocrystals with different Ln3+ doping concentrations and average sizes were prepared by chemical self-combustion. The corresponding bulk materials with various doping concentrations were obtained by annealing the nanomaterials at high temperature. The emission spectra, excitation spectra, and X-ray diffraction spectra were used in this study. It was found that the charge transfer band of Y2O3:Eu3+ red-shifted as particle size decreased, and the charge transfer band in the 5-nm particles obviously broadened toward the long wavelength. It was also found that the profile of excitation spectra corresponding to the 4f5d (4f8 --> 4f(7)5d1) transition changed a lot with the variation of the particle size. The dependence of the excitation spectra of Y2O3:Ln3+ on particle size was investigated.

Rheological and structural details of biocidal iPP-TiO2 nanocomposites

“…The excellent biocidal capabilities exhibited by nanocomposites based on a metallocene iPP and TiO 2 have been reported in previous works [3][4][5], varying either the nanoparticle composition, this ranging from 0.5 to 5 wt.%, at a given compatibilizer content, or the interfacial agent fraction at a specific TiO 2 content of 2 wt.%. This striking antimicrobial activity has been also found by using an ethylene-vinyl alcohol copolymer as polymeric matrix [6][7][8].…”

“…8 units. The germicide behavior exhibited by these nanocomposites is dependent on the microorganisms evaluated [3,5] but, in all cases, a significant improvement of the biocidal activity is detected with the employment of the iPPTi2 nanocomposites.…”

“…Compared with other biocidal agents, an excellent power for destruction of regular bacteria, as B. stearothermophilus, E. coli, S. aureus, P. jadini, and other microorganisms widely present in the environment that cause infections and serious illness, as P. aeruginosa and E. faecalis, has been found in titania nanoparticle-polypropylene nanocomposites [3][4][5].…”

Synthesis, molecular characterization, evaluation of polymorphic behavior and indentation response in isotactic poly(propylene-co-1-heptene) copolymers

“…Incorporation of specific fillers or other polymers can allow spreading out even more its application fields. This addition can be performed either by direct blending of the different components, filled polypropylenes [1][2][3][4][5][6] or blends [7,8], or by polymerization in the presence of fillers [9][10][11].…”

Visible and ultraviolet antibacterial behavior in PVDF–TiO2 nanocomposite films

“…The TiO2 anatase nanoparticles incorporation within polymeric matrices by means of a straightforward and suitably-scalable production methodology has been proved to lead to nanocomposite materials with a significant ultraviolet antimicrobial behavior, against both Gram-negative and Gram-positive bacteria. Thus, an impressive performance has been already described in ethylene-vinyl alcohol (EVOH) copolymers [10][11][12][13], isotactic polypropylene (iPP) [12,14,15] and polycaprolactone (PCL) [16] as polymeric based composites. This excellent biocidal response is associated with the photocatalytic power of anatase nanoparticles.…”