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Article

B. Faridnia, M.M. Kashani Motlagh and A. Maghsoudipour

To evaluate the effect of flux, activator and co‐activator on solid state synthesis of SrAl2O4: Eu2 + , Dy3 +  phosphor, where boric oxide, europium oxide and dispersium…

Abstract

Purpose

To evaluate the effect of flux, activator and co‐activator on solid state synthesis of SrAl2O4: Eu2 + , Dy3 +  phosphor, where boric oxide, europium oxide and dispersium oxide were used, respectively.

Design/methodology/approach

To optimise synthesis condition of long lasting phosphorescence SrAl2O4 phosphor, boric oxide was used as a flux. To improve relative intensity of SrAl2O4: Eu2 +  phosphor, the critical concentration of Eu2 +  was determined. The effect of various concentration of co‐activator on afterglow properties, the effect of Dy3 +  ion on the emission and excitation spectra were examined.

Findings

The SrAl2O4: Eu2 + , Dy3 +  phosphor powders have been synthesised by solid state reaction method. The result of XRD patterns indicated that, addition of 5 mol% B2O3 enhanced the formation of SrAl2O4 at 1,200°C. Investigation on the variation of emission intensity of different phosphors containing different amounts of Eu2 +  revealed that after 6 mol% of Eu2 +  concentration, quenching process occurred. Dy3 +  formed trap levels and results demonstrated that increasing concentration of Dy3 +  up to 5 mol% reduced the relative intensity and increased the decay time.

Originality/value

Using B2O3 as a flux and solid state reaction method for preparation of this phosphor is in good agreement with industrial production and make it economic, because of reduced sintering temperature.

Details

Pigment & Resin Technology, vol. 36 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Sh. Fadaie, M.M. Kashani‐Motlagh, A. Maghsoudipour and B. Faridnia

The purpose of this paper is to evaluate the effect of copolymer and starting material concentrations in homogeneous precipitation synthesis of Yttria nanoparticles and…

Abstract

Purpose

The purpose of this paper is to evaluate the effect of copolymer and starting material concentrations in homogeneous precipitation synthesis of Yttria nanoparticles and red‐emitting nanophosphors Y2O3:Eu3+. N‐isopropylacrylamide and acrylic acid (NIPAM/AAc) and urea are used.

Design/methodology/approach

To optimise synthesis condition of Y2O3:Eu3+ nanophosphor NIPAM/AAc copolymer was used as a modifier and the effect of various concentration of yttrium ions, urea and precipitation time on size, morphology and emission spectra were investigated.

Findings

Using NIPAM/AAc copolymer shows significant improvement on size and dispersion of nanoparticles. It is found that yttrium concentration, varying between 0.006 and 0.03 M, has a profound impact on the average size of particles, which systematically increases from 65 to over 165 nm. The rate of precipitation reaction, however, is shown to be independent of yttrium concentration. In contrast, as urea concentration increases from 0.2 to 5 M, the average particle size exhibits a gradual decrease from 183 to 70 nm. At extremely high urea concentration such as 5 M, a significant level of inter‐particle agglomeration is observed.

Originality/value

Based on this paper, the authors have successfully prepared some promising nanophosphors. The nanoparticles are studied by X‐ray diffraction, transmission electronic microscopy, zeta sizer, Infra red and photoluminescence spectroscopy.

Details

Pigment & Resin Technology, vol. 39 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Amir Maghsoudipour, Mohamad Hassan Sarrafi, Fathollah Moztarzadeh and Ali Aghajani Bazazi

The purpose of this paper is to investigate the effect of boric acid as a flux on the formation of the akermanite phase and optical properties of SrMgSi2O7:Eu,Dy phosphors.

Abstract

Purpose

The purpose of this paper is to investigate the effect of boric acid as a flux on the formation of the akermanite phase and optical properties of SrMgSi2O7:Eu,Dy phosphors.

Design/methodology/approach

The silicate‐based phosphor is prepared by sol‐gel method. Sr(NO3)2, Mg(NO3)2 · 6H2O, Dy2O3, Eu2O3, are added to distilled water in their stoichiometric ratio, the obtained solution are mixed with H3BO3 (in the range of 0.01‐0.5 mol%) and a polymeric compound TESO (C8H2O4Si). At the end, the phase composition and optical properties are investigated using X‐ray diffraction (XRD) and spectrophotometer analysis, respectively.

Findings

The XRD results showed that the akermanite (Sr2MgSi2O7) is the only crystalline phase which is detected in the sample containing 0.05 mol% boric acid. Increasing of boric acid does not have a great effect on the XRD patterns intensity. Spectrophotometer analysis results show three maximum at 365, 395 and 430 nm on the excitation spectra. It also shows intensity of the excitation and emission spectra increased by adding boric acid up to 0.25 mol% and a sudden drop at 0.5 mol% boric acid.

Originality/value

Using boric acid as a flux, enhances formation of akermanite phase at lower temperature with desirable optical properties and a cost‐benefit way for industrial production. In this research, optimum value of boric acid was determined using XRD data, emission and excitation spectra.

Details

Pigment & Resin Technology, vol. 39 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

A.R. Mirhabibi, F. Moztarzadeh, A. Aghajani Bazazi, M. Solati, A. Maghsoudipour and M.H. Sarrafi

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor…

Abstract

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor showed that both had broad bands and that the main emission peak at 469 nm was due to 4f‐5d transitions of Eu+2 and implied that the luminescence centres Eu+2 occupied the Sr+2 sites in the Sr2MgSi2O7 host. The phosphor doped only with Eu ions did not demonstrate the long afterglow phenomenon, but when co‐doped with Dy+3 ions in the SMS matrix, significant long afterglow was observed.

Details

Pigment & Resin Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0369-9420

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Article

B. Guo, P. Yin, J. Xu, F.C. Yi, Y. Dai, Y. Gao and F.Q. Guo

The purpose of this paper is to report on a study which aims to improve the compatibility of the long afterglow phosphors SrMgAl4O8:Eu2+, Dy3+with organic matrix…

Abstract

Purpose

The purpose of this paper is to report on a study which aims to improve the compatibility of the long afterglow phosphors SrMgAl4O8:Eu2+, Dy3+with organic matrix, including its water resistance.

Design/methodology/approach

The phosphors were modified by the lauric acid‐based Al‐Zr coupling agent (CA). Then, they were characterised by attenuated total reflection fourier transform infrared (ATR‐FTIR), pH and electric conductivity in water, scanning electron microscope (SEM), contact angle and fluorescence decay curves before and after modification.

Findings

The pH and electric conductivity displayed the improved water resistance, as the Al‐Zr CA addition increased, and the minimum contact angle with resin decreased from 68.3 to 40.3°C, which showed that the compatibility with organic matrix was enhanced significantly. The afterglow luminous properties were unimpaired.

Research limitations/implications

The researchers are encouraged to test the proposed method and enhance the compatibility further.

Practical implications

This method will extend the applications of phosphors in the paint, coatings, ink and plastics industry.

Originality/value

This paper introduces the lauric acid‐based Al‐Zr CA to modify the luminescent pigments of long afterglow phosphors; it can be also applied to other inorganic powders.

Details

Pigment & Resin Technology, vol. 40 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

B. Guo, P. Yin, J. Xu, F.S. Liu, J.N. Wu, Y. Gao and F.Q. Guo

The purpose of this paper is to improve the anti‐sedimentation of the acrylic resin containing long afterglow phosphors (SrMgAl4O8:Eu2+, Dy3+).

Abstract

Purpose

The purpose of this paper is to improve the anti‐sedimentation of the acrylic resin containing long afterglow phosphors (SrMgAl4O8:Eu2+, Dy3+).

Design/methodology/approach

The phosphors were first modified by the vinylsilane coupling agent MPS (3‐(methacryloxypropyl)‐trimethoxysilane). Then, the acrylic resin containing modified phosphors was synthesised by in situ polymerisation. Meanwhile, the compared blend sample was prepared by pure acylic resin with no modified phosphors in the same content. When the two resins were coated on glass, the films were characterised by ATR‐FTIR, SEM and TGA. The sedimentation performances of liquid resins were also observed.

Findings

Results showed that anti‐sedimentation of acrylic resin with phosphors by in situ polymerisation was enhanced greatly, because the phosphors have been connected with the macromolecule chain, and dispersed homogeneously with no aggregation, so preventing its sedimentation.

Research limitations/implications

Researchers are encouraged to test the proposed method and enhance the anti‐sedimentation further.

Practical implications

This method provides an idea to solve the problem of anti‐sedimentation in luminescent paint containing long afterglow phosphors in practical production and application.

Originality/value

This paper introduced the in situ polymerisation to enhance the anti‐sedimentation of acrylic resin containing long afterglow phosphors and it can be applied also to other inorganic powders.

Details

Pigment & Resin Technology, vol. 41 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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