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This paper aims to introduce a novel approach to the fabrication of photoluminescent materials by coating rare earth aluminate luminescent materials on metallic substrates and a readily manufacturable light source with robust structure in the form of photoluminescent sphere (APS).

The clean and dried stainless steel sphere was sprayed with UH 2593, a white undercoat, the luminescent coating and the weather resistance coating in chronological order.

After adhered onto the stainless steel sphere, the peaks corresponding to the N-H stretching vibrations were changed. The intensity of free N-H stretching at 3,536 cm⁻¹ dramatically decreased and the peak of hydrogen-bonded N-H stretching of PU moved to lower wavenumbers. The red shift of the infrared bands of functional groups was attributed to the strengthened hydrogen bonding. The hydrogen bonding interactions between the stainless steel substrates and the polyurethane coating endowed the APS with excellent adhesive property and also promoted the evenly distribution of the photoluminescent particles in the polymer coating matrix.

This approach can be applicable in the fabrication of the photoluminescent materials. The APS can be used as signs and guiding post in remote areas without sufficient electricity supply and in the seas and rivers with complicated hydrological conditions.

This approach has provided a method to produce tough and durable luminescent signs for remote areas and dangerous seas and explained the functional mechanism of the combined application of metallic materials and non-metallic materials.

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.

To evaluate the effect of flux, activator and co‐activator on solid state synthesis of SrAl₂O₄: Eu^2 +, Dy^3 + phosphor, where boric oxide, europium oxide and dispersium oxide were used, respectively.

To optimise synthesis condition of long lasting phosphorescence SrAl₂O₄ phosphor, boric oxide was used as a flux. To improve relative intensity of SrAl₂O₄: Eu^2 + phosphor, the critical concentration of Eu^2 + was determined. The effect of various concentration of co‐activator on afterglow properties, the effect of Dy^3 + ion on the emission and excitation spectra were examined.

The SrAl₂O₄: Eu^2 +, Dy^3 + 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 Eu^2 + revealed that after 6 mol% of Eu^2 + concentration, quenching process occurred. Dy^3 + formed trap levels and results demonstrated that increasing concentration of Dy^3 + up to 5 mol% reduced the relative intensity and increased the decay time.

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.

The present paper aims to synthesize SrAl2O4:Eu2⁺, Dy3⁺ green-emitting phosphor nano-pigment powder using a combination of citrate – gel processing and microwave-assisted heating route.

Microwave-assisted citrate – gel processing of SrAl2O4:Eu2⁺, Dy3⁺ green-emitting phosphor nano-pigment powder has been carried out by varying the pH and the molar ratio of H3Cit/Al3⁺ + Sr2⁺ +Eu2⁺⁺Dy3⁺ (f/o). X-ray diffraction analysis showed that the produced powders were nearly pure SrAl2O4 phase, in which the SrAl2O4 host phase has the maximum fraction of green-emitting monoclinic SrAl2O4 phase.

Spectrophotometer results revealed that two excitation peaks appeared at 238 and 339 nm and an emission peak at 515 nm. The crystallite size of the green-emitting phosphor nano-pigment powder was about 37 nm as determined by Scherrer’s formula. The best conditions for formation of monoclinic SrAl2O4 phase with high purity were achieved at pH of precursor solution equal to 7 and the molar ratio of f/o equal to 3.

The present research work for the first time (to the best of the authors’ knowledge) has used microwave and sol–gel combination techniques to produce green-emitting phosphor nano-pigment powder (without using any other heating system).

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

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.

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.

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

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

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.

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.

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.

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.

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.

The purpose of this paper is to study the influence of different carbon chain lengths in coupling agents on the water resistance and compatibility of modified long afterglow phosphors and attempt to obtain their modification model and mechanism.

Three saturated-fatty-acid (caprylic, lauric, stearic acid)-based Al-Zr CAs (coupling agent) was synthesised and applied to modify the long afterglow phosphors SrMgAl₄O₈:Eu₂₊,Dy₃₊.

Results show that the coated amount on phosphors decreased from 13.41 to 6.53 per cent with the increased carbon chain length of fatty acid, and the better water resistant and suitability with organic resin can be obtained by lauric-based Al-Zr CA.

Considering that the decomposition process of modified phosphor was related with the decomposition performance of corresponding coupling agents and original phosphor, a method was first proposed to calculate the coated amount on phosphors by thermogravimetric analyser parameters.

Aluminium and its alloys find application to an increasing extent in building construction. Thus in 1965 about 25% of the total consumption of aluminium in Switzerland was taken up by building construction. The material is employed not only for the frames of windows and display windows, doors, facade claddings, etc., i.e. components of a decorative character, but also on an ever‐increasing scale for shell sections, roof structures, cable conduits and so on, i.e. for functional purposes. The versatile application of aluminium can be attributed to a number of favourable properties, not least among which is its good chemical behaviour. In this article we are especially concerned with the stability of aluminium in contact with alkaline building materials. Direct contact between unprotected aluminium and alkaline building materials, such as cement mortar, is as a rule avoided, since the material is protected on the side of the cement by a coat of lacquer or bitumen. For numerous applications, however, knowledge of the behaviour of the unprotected metal can be of advantage to the planning engineer.

The purpose of this study is to explore the feasibility of utilizing agricultural (almond shell, rice husk and wood) waste biochars for partial cement replacement by evaluating the relationships between the physiochemical properties of biochars and the early-age characteristics of cement pastes.

Biochars are prepared through the thermal decomposition of biomass in an inert atmosphere. Using varying percentages, biochars are used to replace ordinary Portland cement (OPC) in cement pastes at a water/binder ratio of 0.35. Characterization methods include XPS, FTIR, SEM, TGA, BET, Raman, loss-on-ignition, setting, compression and water absorption tests.

Accelerated setting in biochar-modified cement pastes is attributed to chemical interactions between surface functional groups of biochars and calcium cations from OPC, leading to the early development of metal carboxylate and alkyne salts, alongside the typical calcium-silicate-hydrate (C-S-H). Also, metal chlorides such as calcium chlorides in biochars contribute to the accelerate setting in pastes. Lower compression strength and higher water absorption result from weakened microstructure due to poor C-S-H development as the high carbon content in biochars reduces water available for optimum C-S-H hydration. Amorphous silica contributes to strength development in pastes through pozzolanic interactions. With its optimal physiochemical properties, rice-husk biochars are best suited for cement replacement.

While biochar parent material properties have an impact on biochar properties, these are not investigated in this study. Additional investigations will be conducted in the future.

Carbon/silicon ratio, oxygen/carbon ratio, alkali and alkaline metal content, chlorine content, carboxylic and alkyne surface functional groups and surface areas of biochars may be used to estimate biochar suitability for cement replacement. Biochars with chlorides and reactive functional groups such as C=C and COOH demonstrate potential for concrete accelerator applications. Such applications will speed up the construction of concrete structures and reduce overall construction time and related costs.

Reductions in OPC production and agricultural waste deterioration will slow down the progression of negative environmental and human health impacts. Also, agricultural, manufacturing and construction employment opportunities will improve the quality of life in agricultural communities.

Empirical findings advance research and practice toward optimum utilization of biomass in cement-based materials.

Stoneware is probably the oldest, or one of the oldest, engineering materials. Two thousand years ago the Romans were using it for water conduits, and the wonderfully preserved pipes that still exist from those days show how imperishable the material is. In this article Dr. Singer examines the reasons for the success of stoneware drainpipes and compares the material with others sometimes used for this purpose. He concludes that no other material yet approaches stoneware for reliability.