Preparation of ZnS particles doped with copper

a technology of zns particles and copper ions, which is applied in the direction of discharge tube luminescence screens, cathode ray/electron stream lamps, electric discharge lamps, etc., can solve the problems of high temperature, large final average particle size (5-20 m), and high temperature needed. , to achieve the effect of enhancing luminescen

Inactive Publication Date: 2005-01-06
ANDRIESSEN HIERONYMUS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0022] It is an object of the present invention to provide a method for the preparation of a dispersion of zinc sulfide particles doped with copper which show enhanced luminescence.

Problems solved by technology

The disadvantages of this method are the high temperature needed, the H2S atmosphere, and the large final average particle size (5-20 μm).
Also the solubility of Cu+ in a ZnS lattice is limited.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

Preparation of ZnS:Cu Dispersion 1 (Control)

[0039] The following solutions were prepared:

Solution 1Zn(SO4).7H2O905.8gCuCl0.15gWaterto 1500ml

[0040]

Solution 2Na2S.9H2O560.8gNH3 (25% in water)24.4mlWaterto 1500ml

[0041]

Solution 3Zn(SO4).7H2O21.6gKCL100gWaterto 1500ml

[0042] The ZnS:Cu dispersion was prepared as follows:

[0043] To solution 3, held at room temperature and stirred at 1500 rpm, solution 1 and solution 2 were added simultaneously at room temperature at a flow rate of 500 ml / min.

[0044] To this predispersion, 250 ml thioglycerol was added and this dispersion was diafiltrated through a Fresenius F60 cartridge by using a 5% solution of thioglycerol in water. This dispersion could be washed successfully until a conductivity of 0.5 mS / cm was reached.

[0045] This dispersion showed no luminescence upon radiation at wavelengths between 250-350 nm.

example 2

Preparation of the ZnS:Cu-Dispersion 2 (Control)

[0046] The following solution was prepared:

Solution 4Zn(SO4).7H2O905.8gCuCl0.15gThioureum58.7gDWto 1500ml

[0047] The ZnS:Cu dispersion was prepared as follows:

[0048] To solution 3, held at room temperature and stirred at 1500 rpm, solution 4 and solution 2 were added simultaneously at room temperature at a flow rate of 500 ml / min.

[0049] To this predispersion, 250 ml thioglycerol was added and this dispersion was diafiltrated through a Fresenius F60 cartridge by using a 5% solution of thioglycerol in water. This dispersion could be washed successfully until a conductivity of 0.5 mS / cm was reached.

[0050] This dispersion showed no luminescence upon radiation at wavelengths between 250-350 nm.

example 3

Preparation of the Zn(Cu)S-Dispersion 3 (Control)

[0051] The following solution was prepared:

Solution 5Zn(SO4).7H2O905.8gCuCl0.15gSodium thiosulphate58.7gWaterto 1500ml

[0052] The ZnS:Cu dispersion was prepared as follows: To solution 3, held at room temperature and stirred at 1500 rpm, solution 5 and solution 2 were added simultaneouly at room temperature at a flow rate of 500 ml / min.

[0053] To this predispersion, 250 ml thioglycerol was added and this dispersion was diafiltrated through a Fresenius F60 cartridge by using a 5% solution of thioglycerol in water. This dispersion could be washed successfully until a conductivity of 0.5 mS / cm was reached.

[0054] This dispersion showed no luminescence upon radiation at wavelengths between 250-350 nm.

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Abstract

An improved method for the preparation of a dispersion of ZnS particles doped with copper is disclosed. The method comprises the step of performing a precipitation by mixing together a zinc salt, a sulfide, and a citrate or EDTA complex of copper ions, dissolved in several aqueous solutions. Enhanced luminescence is obtained.

Description

RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 10 / 050,317 filed Jan. 16, 2002, pending, which claims the benefit of U.S. Provisional 60 / 271,127 filed Feb. 23, 2001.DESCRIPTION OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method for preparing a dispersion of ZnS particles doped with copper ions showing enhanced luminescence. [0004] 2. Background of the Invention [0005] Luminescence of sulfides, selenides and tellurides of Zn, Sr, Cd, Hg, and others, is due to the presence of luminescent centres in the host crystal. For instance, Cu+ centres in ZnS give rise to luminescence at 520 nm. Mn2+ is also a luminescent centre for ZnS. The emission maximum in this case is situated at about 590 nm. [0006] The method that is usually applied for the preparation of (electro)luminescent particles is the sintering method. In this procedure bulk ZnS and e.g. MnS are mixed and sintered at high temperatur...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C09K11/58
CPCC09K11/584
InventorANDRIESSEN, HIERONYMUS
OwnerANDRIESSEN HIERONYMUS