Fluoride Fluorescent Material Core-Shell Structure for Water Resistance
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Solution Overview
Problem
Conventional fluoride fluorescent materials activated by tetravalent manganese ions lack water resistance and long-term reliability, making them unsuitable for applications requiring high durability.
Innovation Solution
A method for producing a fluoride fluorescent material involving the reaction of potassium ions with tetravalent manganese ions and second complex ions in a hydrogen fluoride medium, followed by the addition of a reducing agent and additional ions, resulting in a dispersion that forms particles with a lower surface concentration of manganese ions, enhancing water resistance and light emission properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional fluoride fluorescent materials activated by tetravalent manganese ions are used, then red light emission with narrow half band width is achieved, but water resistance and long-term reliability deteriorate
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the core contains Mn4+ ions for red light emission and the shell contains protective fluoride materials. This allows the emission function to be localized in the core while the shell provides water resistance and stability, resolving the contradiction between light emission performance and water resistance.
Solution Approach 2:
The patent uses composite materials by combining Mn4+-activated fluoride particles with protective shell materials such as SiO2, TiO2, or Al2O3. This composite structure maintains the narrow half-bandwidth red emission of Mn4+ while the shell provides enhanced water resistance and long-term reliability, simultaneously achieving both desired properties.
2Illumination intensity
If conventional fluoride fluorescent materials are used, then excellent color reproduction is achieved, but durability in moisture environments deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-forming a protective shell around the Mn4+ fluoride particles before they are exposed to moisture environments. This shell is specifically designed to prevent water penetration and chemical degradation, ensuring long-term durability while preserving the excellent color reproduction properties of the Mn4+ emission.
Solution Approach 2:
The protective shell acts as an intermediary between the Mn4+ fluorescent core and the external moisture environment. It mediates by blocking water molecules from reaching the sensitive fluoride lattice, thereby protecting the structural integrity and emission properties of the Mn4+ particles while allowing the excellent color reproduction to be maintained over time.
3Manufacturing precision
If Mn4+ activated fluoride particles are synthesized, then narrow emission spectrum is achieved, but water resistance deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the fluorescent material into distinct functional segments: an inner core containing Mn4+ ions that provides the narrow emission spectrum, and an outer shell that provides water resistance. This segmentation allows each component to optimize its specific function without compromising the other, achieving both spectral precision and environmental stability.
Solution Approach 2:
The patent uses composite materials to create a core-shell structure where the Mn4+ fluoride core maintains the narrow emission spectrum and the protective shell (SiO2, TiO2, or Al2O3) provides water resistance. This composite approach enables simultaneous achievement of manufacturing precision in emission characteristics and reliability in moisture environments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces a red light-emitting fluoride fluorescent material with excellent water resistance and long-term reliability, suppressing the formation of manganese dioxide on the surface, which maintains luminance and allows for wider color reproduction.
Implementation Method 1
adding a reducing agent to the dispersion
Implementation Method 2
fluoride fluorescent material
Data Source
AI summary
The present invention provides a method for producing a fluoride fluorescent material, the method comprising:contacting potassium ions with first complex ions comprising tetravalent manganese ions and second complex ions comprising at least one member selected from the group consisting of elements belonging to Groups 4 and 14 of the Periodic Table in a liquid medium comprising hydrogen fluoride to obtain a dispersion containing fluoride particles represented by the following formula (I):K2[M1−bMn4+bF6] (I)wherein M is the at least one member selected from the group consisting of elements belonging to Groups 4 and 14 of the Periodic Table, and b satisfies the relationship: 0<b<0.2;adding a reducing agent to the dispersion; andcontacting the fluoride particles in the dispersion to which the reducing agent is added with at least one of additional second complex ions and additional potassium ions in the presence of hydrogen fluoride to obtain a fluoride fluorescent material.