Most commercial glow-in-the-dark paints are based on the system SrAl2O4:Eu,Dy, which offers good glow effects and long (>6h) glow times only in the
green-aqua color range. Recently CaAl2O4:Ce was found to have phosphorescence lasting a remarkable 10 hours in the blue-violet range:
I'm now sort of interested in the production of this salt. Do phosphorescent materials generally require as laborious methods of production as shown
in the paper to achieve good phosphorescence effects, or will merely firing CaCO3 with Al2O3 and 1-2% Ce2O3 in a kiln achieve some effect? Has anyone
here experimented with aluminate phosphors?
[Edited on 21-8-2015 by clearly_not_atara]byko3y - 21-8-2015 at 14:12
The problem with prosphors preparation is that you need 99,9% pure reagents. 1% amount of iron will make any phosphorescence impossible.IrC - 21-8-2015 at 17:41
Take the time to search this site. I have no idea what they mean by recent considering I was making Calcium Aluminates doped with Ce and many batches
doped with a wide range of Lanthanides in many experiments I discussed in threads here years ago. Yes Fe is poison to any glow powder formula in
incredibly minute amounts. I discussed it all at length, search this site. I learned to use non metal cutting wheels to get my starting metals from
larger pound range chunks instead of using a hacksaw. Even after intense cleaning batches were still ruined by microscopic particles of Fe I could not
even see which remained in microscopic crevices in my starting metals. Find the threads and read the many patents I posted. More than a few of which
covered Calcium Aluminates doped with Ce and these were from years ago. No you cannot easily make them the glow will decay rapidly. Study the required
fluxes and building quartz tube furnaces where you can flow pure hydrogen through the mix at temperatures in the cone 10 range. This is how you get
your glow powders to shine in the 8 to 12 hour range. You can even make small batches easily in a microwave but only when you are running reducing
gasses through the batch in a kiln for an hour or longer as well as using the proper fluxes will you achieve ultra long persistence to the glow. blogfast25 - 21-8-2015 at 17:59
Any chance of you digging up some of these older treads?IrC - 21-8-2015 at 21:00
Here are a few but lacking time to keep looking, I think he should search around 2005 to 2007 since I remember there were several threads on this and
related subjects back then. I searched 'glow powder' but it seems other keywords would be useful to search. Much was on Zinc glow powders or Sr
Aluminates but even in those threads useful information about the reducing process should be studied. Somewhere it sticks in my mind a comment on the
reduction for long glow persistence by a member who is really good at chemistry. He said the kiln work (sintering stage using fluxes) was the
beginning step but to get from the +3 to +2 state required for long persistence was the reason for the next step of high temperature reduction in
Hydrogen gas (at all other times in the kiln an Argon flow is required to keep Oxygen out of the process). These steps I had long known from patent
study and my own experiments but no one before had explained the mechanism. I don't remember which member it was or what thread. Somewhere on the site
I'm sure but it may be hard to find. I didn't have time to read again these threads linked below possibly it was a post in one of them?
"Impurities even at extremely low levels create traps which wreck the desired result. Also important is particle size and improper mixing. One point
missed by most is attention to atmosphere. Plug the ends of your tube furnace with a material such as Kaowool. Insert a smaller quartz tube to run the
proper gas in while at high temperature. For ZNS/Ag or Cu you need O2. However for Lanthanide doped Aluminates O2 must be avoided, you need H2 or a
reducing atmosphere. O2 will poison the long persistence phosphors. During the times in the furnace you should not be reducing, a slow Argon flow is a
must. Otherwise the glow will drop from a dozen or more hours to mere seconds. I know as my powders which have a persistence of around 24 hours took a
long time to perfect. As an example I tried using a file and sawing (not both at once) to get flakes from some of my dopant metals which are extremely
hard to work, for use in my doping. Failure always. Turned out even PPM or likely PPB traces of iron is so poisonous to persistence that failure is
guaranteed. Fe traps are detrimental. In the end with home experimenter techniques the only simple method is using a fiber cutting wheel on a Dremel
tool to get a small chunk of the desired metal. Then dissolving this to use in making a salt of the metal, filtering and recrystallization for purity.
The salt which works best is a nitrate by the way.
The next failure by experimenters is failure to use the proper flux while processing in the kiln. There are many useful patents to study before you
experiment, a great money and time saver. A quick and dirty way to achieve decent persistence is experimenting with Calcium Aluminates, Eu doping,
using a blowtorch (only using the proper reducing flame area) in a boat of Al2O3. This method fails in ZnS Ag scintillation material experiments. You
just cannot control the atmosphere well enough. Sometimes a small area will work after crushing. Typically this portion of material was inside a
larger piece of the material and thus more protected from the air.
---------------------------------------------------------
aluminum hydroxide
------------------------------
5492542
6,887,454 Process for the production of aluminum hydroxide
4234559
4340579
4530699
4574074
5130113
5158577
6,887,454 Process for the production of aluminum hydroxide
6,162,413 Alpha-alumina and method for producing same
6,106,800 Method for producing alpha-alumina powder
5,916,536 Production of calcined alumina with a crystallite size which can be regulated with a narrow dispersion
5,445,808 Process for preparing ultra-white alumina trihydrate
5,225,229 Aluminum hydroxide production
5,149,520 Small sized alpha alumina particles and platelets
-------------------------------------------------
4,606,846 Mixed rare earth metal, divalent transition metal, aluminum oxide
3,931,591 Q-switching device for glass lasers
3,931,590 Q-Switching device for glass lasers
4,115,312 X-ray fluorescent luminescent cadmium tungstate compositions
6,407,020
6699598 Laminar body having phosphorescent properties, process for producing it and its use
6,654,079 Liquid crystal color display screen comprising a phosphor layer
6,528,186 Stratified composite with phosphorescent properties, method for the production and the use thereof
6,398,970 Device for disinfecting water comprising a UV-C gas discharge lamp
6,190,577 Indium-substituted aluminate phosphor and method for making the same
5,985,174 Fluorescent material used in an active dynamic liquid crystal display device and method for manufacturing
the same
5,575,050 Method of assembling electronic component
5,402,036 Low pressure mercury vapor discharge lamp having double layers
5,105,121 Lanthanum cerium aluminate phosphor and an electrical discharge device containing the same
5,015,497 Cathode for electron tube and manufacturing method thereof
4,837,481 Cerium and terbium activated luminescent material and mercury vapor discharge lamp containing the same
4,800,319 Low-pressure mercury vapor discharge lamp
5,065,023 Solid state high resolution photography and imaging using electron trapping materials
4,733,126 Phosphor and fluorescent lamp using the same
4,518,985 Projection type green cathode ray tube, method for manufacturing phosphor screen for the same, and projection video device using the same
4,382,207 Luminescent material and discharge lamp containing the same
4,983,834 Large area particle detector system
4,940,603 Thin film inorganic scintillator and method of making same
4,915,982 Method of making thin film photoluminescent articles
4,879,186 Photoluminescent materials for outputting reddish-orange light and a process for making the same
4,855,603 Photoluminescent materials for radiography
4,842,960 High efficiency photoluminescent material for optical upconversion
4,839,092 Photoluminescent materials for outputting orange light
4,830,875 Photoluminescent materials and associated process and infrared sensing device
4,822,520 Photoluminescent materials for outputting blue-green light
4,818,434 Thermoluminescent material including fusible salt
4,812,660 Photoluminescent materials for outputting yellow-green light
4,812,659 Infrared sensing device outputting blue-green light
4,806,772 Infrared sensing device outputting orange light and a process for making the same
4,755,324 Thermoluminescent material
4,348,299 Method for preparing inorganic sulfides
3,977,991 Manganese-and-magnesium-activated strontium sulfide phosphors
6,684,557 Process for making an aquatic lure phosphorescent and charging same with an ultraviolet light
6,346,326 Coated moisture impervious red phosphors
4,374,037 Method for preparing divalent-europium-activated calcium sulfide phosphors
5,006,366 Photoluminescent material for outputting orange light with reduced phosphorescence after charging and a process for making same
4,992,302 Process for making photoluminescent materials
4,857,228 Phosphors and methods of preparing the same
4,855,603 Photoluminescent materials for radiography
4,842,960 High efficiency photoluminescent material for optical upconversion
4,839,092 Photoluminescent materials for outputting orange light
4,830,875 Photoluminescent materials and associated process and infrared sensing device
4,822,520 Photoluminescent materials for outputting blue-green light
4,812,660 Photoluminescent materials for outputting yellow-green light
4,806,772 Infrared sensing device outputting orange light and a process for making the same
4,436,646 Green-emitting phosphor for cathode-ray tube
4,075,495 X-ray luminescent screen
4,057,507 Europium and samarium activated rare earth oxysulfide phosphor
3,950,668 Cathode ray tube containing silicon sensitized rare earth oxysulfide phosphors
6,346,326 Coated moisture impervious red phosphors
4,983,834 Large area particle detector system
4,864,536 Optical memory system and method of using the same
4,857,228 Phosphors and methods of preparing the same
4,855,603 Photoluminescent materials for radiography
4,842,960 High efficiency photoluminescent material for optical upconversion
4,839,092 Photoluminescent materials for outputting orange light
4,830,875 Photoluminescent materials and associated process and infrared sensing device
4,822,520 Photoluminescent materials for outputting blue-green light
4,818,434 Thermoluminescent material including fusible salt
4,812,660 Photoluminescent materials for outputting yellow-green light
4,806,772 Infrared sensing device outputting orange light and a process for making the same
4,755,324 Thermoluminescent material
4,057,507 Europium and samarium activated rare earth oxysulfide phosphor
6,081,069 Phosphor, cathode-ray tube, fluorescent lamp and radiation intensifying screen
5,814,932 Phosphor, cathode-ray tube, fluorescent lamp and radiation intensifying screen
5,808,409 Phosphor, cathode-ray tube, fluorescent lamp and radiation intensifying screen
5,644,193 Phosphor, cathode-ray tube, fluorescent lamp and radiation intensifying screen
4,526,873 Transparent, mullite glass-ceramics containing ZnO and method
4,328,299 Polychromatic glasses and method
4,167,417 Fluorescent inorganic pigment
4,102,805 Cathodoluminescent and photoluminescent glasses
3,962,117 Cathodoluminescent glasses activated by manganese
3,935,119 Luminescent device, process, composition, and article
6,684,557 Process for making an aquatic lure phosphorescent and charging same with an ultraviolet lig
6,039,894 Production of substantially monodisperse phosphor particles
5,958,591 Electroluminescent phosphor particles encapsulated with an aluminum oxide based multiple oxide coating
5,917,279 Intermediate layer in electroluminescent arrangements containing finely divided inorganic particles
5,908,698 Encapsulated electroluminescent phosphor and method for making same
5,619,098 Phosphor and fluorescent display device
5,593,782 Encapsulated electroluminescent phosphor and method for making same
5,439,705 Encapsulated electroluminescent phosphor and method for making same
5,431,851 Composite electroluminescent phosphor
5,418,062 Encapsulated electroluminescent phosphor particles
5,366,834 Method of manufacturing a cathode ray tube phosphor screen
5,309,071 Zinc sulfide electroluminescent phosphor particles and electroluminescent lamp made therefrom
5,294,368 Method of making a composite electroluminescent phosphor
5,156,885 Method for encapsulating electroluminescent phosphor particles
5,094,185 Electroluminescent lamps and phosphors
4,961,956 Electroluminescent lamps and phosphors
4,855,189 Electroluminescent lamps and phosphors
4,181,753 Process for the production of electroluminescent powders for display panels and coating the powders with zinc phosphate
4,097,776 Coated electroluminescent phosphors
4,024,298 Method of providing storage dielectric of phosphor particles coated with secondary emissive material
4,021,588 Method for preparing filter-coated phosphor particles
5,105,121 Lanthanum cerium aluminate phosphor and an electrical discharge device containing the same
4,840,747 Method for producing a terbium activated cerium magnesium aluminate phosphor
4,757,233 Efficient UV-emitting phosphors based on cerium-activated calcium pyrophosphate and lamps containing the same
4,441,049 Luminescent material and discharge lamp containing the same
4,246,630 Ultraviolet emitting Ce alkaline earth aluminate lamp phosphors and lamps utilizing same
4,153,572 Ultraviolet emitting CeYMg aluminate fluorescent lamp phosphor for psoriasis treatment
4,088,922 Cerium magnesium aluminate luminescent compositions, and lamps utilizing same"
