Fluorescence Materials with Long Afterglow
Development of High-Effective Light-Reserving Fluorescence Materials with Long-Lived Afterglow for a Wide Spectrum of Applications
Tech Area / Field
- MAT-ELE/Organic and Electronics Materials/Materials
- CHE-SYN/Basic and Synthetic Chemistry/Chemistry
3 Approved without Funding
Platan R&DI with pilot plant, Russia, Moscow reg., Fryazino
- VNIIKhT (Chemical Technology), Russia, Moscow
- TU Delft, The Netherlands, Delft\nGeneral Phosphorix / Ardsley Park Science and Technology Center, USA, NY, Ardsley
Project summaryThe project is referred to area of creation of new materials, is particular to engineering of light-reserving fluorescence materials with long-lived afterglow; such materials are beaming a light within many hours after cancellation of energizing radiation. The indicated luminophors can be applied in systems of the emergency indicating and independent(autonomous) lighting at extraordinary situations; it is possible to use them for road sectoring and constructions of a beam guard rail, in advertising and entertainment fixtures, scenery, covers of bridges or piles, in systems of fire-safety and warning, in light-accumulators and solar cells. It is possible to use such materials for painting (covering) large buildings and construction (such as offshore platforms, moorage walls of harbour facilities, oil tubular derricks and cocks), for special clothes of police, fire-services, clothes of the schoolboys and pers, etc. These materials have capacity to light-reservation at affecting different kinds of ionizing radiations (x-ray, gamma- ray); it allows using this material in engineering of a radiation control.
The first generation of light-reserving luminophors with long-lived afterglow was grounded on substances by type AII BVI (CaS:Bi or ZnS:Cu). The poor stability in atmosphere leads to quick breaking down of these materials on air, at a solar radiation and affecting of water; it confined a circle of their applications only by enclosed spaces at persistence of temperature and damp. The second generation of light-reserving luminophors is connected with applying of aluminates of the second major subgroup of a Periodic Mendeleev system, i.e. (Ca,Sr,Ba)O·Al2O3.
Within the framework of the project, it is planned to elaborate new more effective light-reserving luminophors of a third generation, distinctive features which one will be:
– the principally new dodge of reservation of quanta of energizing light by inter-crystalline recharge in recombination steams of new materials;
– the greatest possible high concentrations (1020-5×1021/см3) of donor and acceptor alloying components in ionic lattices with a minimum amount of dot defects;
– high-energy responsiveness of a material to stimulation;
– optimal energy zone structure of synthesized materials; this structure combines controling photoconductivity at shortwave stimulation with a high activation energy of migration of the carriers in wide-zone (predominantly ionic) matrix;
– new materials have crystalline-chemical order and thermodynamic strength of crystal lattice of synthesized oxy-anion substances.
Constructed on these principles, new generation of light-reserving luminophors with long-lived afterglow (LLA) will allow providing following parameters (with comparison with existing materials):
– increasing of stocked light-quantity and heightening of brightness of starting glow;
– increasing of a working time after termination of an exterior lighting;
– higher thermal-, hydro- and atmosphere- resistance;
– full ecological safety;
– operability for applying in different articles(work-pieces) of building, textile, poly-graphic and other products;
The applicants have a reach experience in this area. PLATAN during more than 35 years is carrying out operations on different aspects of luminophors for needs of a national economy, including operation on fundamental and applied researches of light-reserving materials. In result, more than 50 various types of luminophors were created, including maiden Russian luminophors with long-lived afterglow LDP-1,2,3. The source of raw materials is determined. The experimental batches of materials are manufactured on a pilot line. The various articles(work-pieces) with applying of materials LDP are created, for example, light-reserving paints, plastics, facing plates, etc.
At the same time, the existing materials have series of deficiencies; the major of which one are low-level of starting brightness (< 2-3 kJ/м2), poor hydro-stability, poor range of colours. Another problem of existing materials is big size of luminophor grains (agglomerates and large particles of un-regular shape); it does not allow using a material for a lot of products: lacquers and paints for spray, synthetic filaments, colors for poly-graphs, for coloring in an electrical field, etc. At the same time, the large aggregate size of a luminophor results in unfairly large losses of a material on filter elements of extruders, increase of cost of articles(work-pieces), decrease of intensity of glow of articles(work-pieces) and, as result, efficiency of their applying.
The decreasing of the sizes of fragments of a luminophor by simple mechanical crushing in ball mills gives negative results, because of a sharp decreasing of a luminescent emission of a luminophor during a dispersion (grinding) of a material. A basic solution of this problem would be development of method of production of a micro-dispersed luminophor immediately during synthesizing and usage of “soft” methods of after-synthesis dispersion. Such approach for materials, applied in luminophors LDP-1.2,3, till now is not realized.
The purpose of project is the development of methods of synthesizing of effective light-reserving fluorescence materials with long-lived afterglow of a third generation, which one will have “inaccessible or unapproachable before parameters”; the performance of project will allow developing material for a broad circle of different articles(work-pieces) at minimum expenditures.
The realization of the project will allow elaborating new materials for the Russian and European industry (needs of these materials equal some billions euro annually); at the same time the project will allow receiving a rich experimental material for further progressing of physics, materials technology and know-how of synthesizing of fluorescence materials.
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