Sol–gel synthesis of transition-metal ion conjugated alumina-rich mullite nanocomposites with potential mechanical, dielectric and photoluminescence properties

Abstract

Mechanical, dielectric and photoluminescence properties of transition-metal ions doped mullite nanocomposite synthesized via alkoxide hydrolysis.

Synthesis of nanocrystalline photoluminescent mullite using sacrificial cotton wool and filter paper templates

“…PL bands in UV region reflected at wavelengths of 312, 324, 347, 362, and 379 nm with visible region PL bands being centered at 407, 424, 436, and 460 nm . No substantial shift occurred in the PL emission wavelengths for doping, sintering temperature or template used.…”

“…In current years, studies on the photoluminescence properties of mullite showed that the luminescence is supposed to originate from the radioactive recombination of photo‐excited holes with electrons occupying the oxygen vacancies present in mullite structure. Photoluminescent mullite thus finds its probable application as fluorescent probes for sensing and detection as well as biological delivery system …”

“…The physico‐chemical properties of mullite are closely related to the synthesis procedure and can be significantly augmented by using suitable dopants . Till date, synthesis routes of mullite includes sintering of natural aluminosilicate clays, Al 2 O 3 and SiO 2 powders, hydrothermal synthesis, spark plasma sintering, sol‐gel synthesis, chemical vapor deposition, spray pyrolysis etc among which sol‐gel technique has been established to be the energetically favorable, and chemically pure one.…”

Impact of annealing on optimization of various thermal, structural, and optical parameters of spinel ‘gahnite’ for device fabrication

“…In the process of blue emission at 405 and 488 nm, the excited electrons have to cross the bandgap, losses energy and then must go down to conduction band of the ZnAl 2 O 4 nanopowder. Following the several possible down transitions, the electron shift to the lower energy in the valence band [37,38]. It is considered that s and p orbital's electron from Al 3+ contribute to the lower edges of the conduction band while the 3d orbital's electron of zinc ion constitutes the upper edge of the valence band [30].…”

Ultrasound promoted synthesis and properties of chitosan nanocomposites containing carbon nanotubes and silver nanoparticles

“…Chitosan films contain small amounts of H + , NH3 + and acetate ions and the behaviour of tan δ can be explained in terms of ion migration as well as enhanced polarization causing higher losses [50].…”