A high-temperature solid-phase method

Preparation Materials 

Editor 

A high-temperature solid-phase method 

Afterglow prepared by high temperature solid material is a more traditional approach phase reaction, this method is used widely. In general, the general operation of the solid phase reaction is a solid powder material. glow in the dark dye‍ To achieve the required purity of the starting material by a certain percentage weighing and adding a certain amount of flux is homogenized thoroughly mixed, then under certain conditions (temperature, atmosphere, and time) for burning. Stoichiometric ratio of luminescent material according to the exact formula, placed in high-temperature resistance furnace in a protective gas atmosphere or a reducing atmosphere 900 ℃ ~ 1450 ℃ burning 2h-5h Serve. Burning process, the type and rate of co-solvent and doped with ions and so on structure and optical properties of long afterglow luminescent materials have a significant influence. 

Since the reaction conditions of high temperature solid-phase method of control, reducing agent, flux selection and preparation of raw materials aspects are becoming more optimized production processes mature, they have been widely used. For example: red afterglow material sulfide system is an alkaline earth metal carbonate, sulfur powder, and select the appropriate mix of rare earth oxides and flux calcined, but also the direct use of alkaline earth metal sulfates and rare earth oxides, flux mix baking process. [2] 

Sol - gel method 

For high-temperature solid-phase method ignition temperature is high, the preparation of luminescent material coarser particles by milling the crystalline material susceptible to damage shortcomings, it has developed a number of other glow in the dark material‍ ways. As a sol-gel method in which wet chemical methods in materials science community has attracted wide attention. This method originated in the 18th century, the application of this method has been very extensive. 

Sol-gel method is the use of specific materials in the precursor is hydrolyzed to form a sol, under certain conditions, and then the solvent was evaporated by a heat treatment, the sol into a gel network structure, and then into the post-treatment process through the formation of suitable nanomaterials a method for preparing the basic process of the nanomaterials used are as follows: 

Raw material -> dispersible system -> sol -> gel -> nanomaterials 

Prepared by the sol-gel technique is the use of luminescent material is mainly a metal alkoxide method, i.e., a metal alkoxide as a starting material into the perhydrolysis reaction, sol-gel polymerization reaction. Zhang Dong and his collaborators were prepared by sol-gel method ZnAl2O4: Mn material, the sintering temperature lower by 100 compared with the traditional method  200 ℃. [3] 

In recent years, inorganic complexes were prepared by the sol-gel gradually people's attention, which is mainly prepared by Pechin method is used, the use of citric acid and ethylene glycol esterified preparation Sol, this quick and easy method of experiment costs low compared with the metal alkoxide method. 

3 Combustion 

Combustion method is a method by means of combustion synthesis precursor material. When the reaction was allowed to reach the ignition temperature of the exothermic reaction, a method to ignite subsequent exothermic heat of reaction is maintained with the material prepared in the combustion products is proposed. The main principle of this method is the reaction of the corresponding raw material nitrate, urea was added as a fuel (reducing agent), is heated at a temperature a few minutes, by vigorous oxidation-reduction reaction, the overflow amount of gas, thereby burning, several after ten seconds to get fluffy foam-like material, not Jietuan easily crushed. This method has considerable applicability of gas generated during combustion is also used as protective gas. Operation is generally as follows to synthesize SrAl2O4: Eu, Dy, for example, the SrCO3, Al (NO3) 3, Eu2O3 and Dy2O3 nitrate solution was mixed by chemical, urea and adding the appropriate acid dissolved, has moved quickly warming to about 600 ℃ muffle furnace, with the evaporation of water, and after a few minutes, and the nitrate as an oxidizing agent of urea as a reducing agent the reaction occurs, and then burning the gas overflow, this process is very short, only ten seconds , the product was obtained after combustion. glow in the dark stones‍ After the product was taken out and cooled to obtain a product that is milled. When using this method can greatly reduce the oven temperature, is an energy efficient way. 

In addition to the persistence of several methods for material preparation methods, as well as hydrothermal synthesis, microwave-assisted synthesis, chemical precipitation method. By using these new synthetic techniques used, the research results show that to obtain luminescent materials breakthrough performance increase is also possible to obtain a light emitting material can not be obtained conventional preparation techniques, and to obtain a new kind of light emitting material, to further widen the long afterglow Research applications. ‍

Luminescence mechanism

A hole transport model 

For such materials, the first model is made in such SrAl2O4 Matsuzawa: Eu, Dy hole transport system model proposed. Based on this model, Matsuzawa that in Long Afterglow SrAl2O4: Eu, Dy in, Eu electron trapping centers, glow in the dark dye‍ Dy is the hole-trapping centers. When the material is excited by UV, Eu can capture electrons into Eu, resulting hole valence band are generated by capturing Dy Dy, after stoppage of the excitation, the relationship of thermal motion, the occurrence of the escape hole, and the above process through the opposite result of the process and characteristics of the light-emitting Eu schematic diagram shown in Figure 3. The model Eu and Dy in a variety of long-lasting co-doped materials have been widely interpreted as a mechanism of reference become a common interpretation Eu and Dy co-doped mechanism of long-lasting material. 

2 displacement coordinate model 

Displacement coordinate model was glow in the dark material‍ first Jianrong and Su Qiang et al. Figure 3 is a schematic diagram of the displacement coordinate model. A is the ground level of Eu2 +, B for its excited state level, C level of defect levels. C may be incorporated into the impurity ions may be some defects caused by defects in the matrix of the levels. Su Qiang and others that C can play the role of electron capture. Under the effect of the external light source, excitation by electron transition from the ground state to an excited state (a), part of the electron-emitting transition back to a lower energy state (2). Another part of the electronic relaxation processes by energy stored in the defect and C in (3). When the electron absorbs energy defect level, re-excited by return to excited states, the transition to the ground state and emit light. The duration and the number of electrons stored in the defect levels, and absorb energy (heat) on the twilight, the more the number glow in the dark stones‍ of electrons in the defect level, the longer the afterglow time, energy absorption and more, resulting in continuous light. 

Long-lasting glow in the excitation light irradiation

Biological applications 

Long-lasting glow in the excitation light irradiation stopped emitting substance can still ongoing phenomenon. Long afterglow luminescent material does not contain toxic heavy metals, can inspire before detection and imaging, glow in the dark dye‍ biological sensing and imaging to achieve in the "free excitation" condition, thus effectively avoiding the interference generated in situ inspired background. Despite the long afterglow luminescent materials have the advantage, but until 2007 only the afterglow materials used in biological sensing and imaging reports. Chermont sol-gel method, such as the use of high-temperature synthesis of silicates with near-infrared fluorescent afterglow nanomaterials and applied vivo imaging (Figure 3). The method was successfully avoids potential damage to organisms traditional fluorescence excitation light source analysis methods, the first time in vivo "free excited" fluorescence imaging. 

Ca0.2Zn0.9Mg0.9Si2O6: Eu, Dy, Mn afterglow nanoparticles in vivo imaging results (A) prior to injection, the first nanoparticle 6 W UV lamp placed 2 cm at the excitation 5 min. (B) respectively, followed by three backs of mice injected with different concentrations in different positions (100, 10 and 1μg/mL) nano-particle suspension (20μl). For 2 min using the acquisition time, wherein fluorescence is easily glow in the dark material‍ monitored two larger doses (2μg and 200 ng) issued. Nano-particles (C) of the mice after intramuscular injection and dispersion of 90 s 

Li Zhan-jun and his collaborators reported the use of MCM-41 as a template for preparing long afterglow materials for biological and cell imaging (Figure 6), and its clever use of MCM as a template, the use of MCM-41 can get clever morphology better spherical nanoparticles, although the material during sintering temperature longer prone to collapse, but the resulting sintered material size and particle size on the nm scale dispersion better. 

? PEG-coated nanoparticles for in vivo afterglow imaging 

2012 Maldiney et PLNP of PEG-coated material and the surface-modified with biotin, and between the avidin biotin interaction so strong that the dissociation constant Kw 10 or less. They Task Force to detect the use of this material is highly expressed avidin surface of glioma cells, the effect is very sensitive and can be used glioma cell imaging (Figure 7).

Figure 7 biotin and PEG-coated nanoparticles for glow in the dark stones‍ afterglow avidin detection sensor detection and BT4C cells 

Luminous paint glue with the use of technology to support

Luminous ink is luminous and ordinary ink mixed together by a certain percentage . After absorb sunlight or natural light certain time, you can continue to glow in the dark for several hours or more. With high heat resistance, surface abrasion resistance , suitable for all kinds of paper , textiles , decorative aggregate, metals , ceramics and other materials are . Luminous and luminous ink preparation method :
   Luminous transparent resin applied to neutral
   Selection of c -type 20-40, d -type 10-15, e -type , such as smaller particle size 5-10 luminous paint.
   Phosphorescent pigment is generally used in an amount of 30-50 % of the total , or to determine the amount of the pigment according to the luminous emission luminance requirements. Ink
       Water-based luminous paint luminous content , photoluminescent pigment suppliers brightness light-emitting ink printed pattern , the longer lighting time .
  Luminous pigment can not grind , available pe plastic containers or pea gravels, enamel -lined container with high-speed dispersion stirring.
  Do not use a heavy metal compound additives .
   Depending on the selection of different types of substrates and transparent ink formulation .
Such as: metal substrate material should be used in metallic ink , substrate material should be selected for the pvc pvc ink.

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glow in the dark dye Temperature change ink is also used in the Teapot

 Currently , the market appeared discolored teapot, discolored toad . The teapot is the use of color temperature variation principle, the ordinary teapot surface coating layer of ink temperature change . When the hot water pouring teapot, teapot on the discoloration occurs . This peculiar change gives people a brand new eyes and ears . Teapot adds to the general psychedelic colors.
 Since ancient times " need a good pot of tea ," said one , photochromic masterbatch is a teapot for the top grade of tea utensils . Teapot territory of China , is the origin of the best Yixing . The Teapot culture, but also Chinese traditional culture can not be an integral part . Teapot is a practical daily life utensils for tea and tea drinking . Teapot in Yixing, Jiangsu origin , also known as Yixing teapot . Teapot making its long history and ancient and beautiful art form become a kind highly collectible collectibles and appreciate the value of art - ink temperature change .
Teapot , Jiangsu Yixing most prestigious. Began in the Northern photochromic sheets, flourished in the Ming and Qing dynasties , a modern prosperous during the peak period is unique in the history of purple , diversification celebrity men , technology and styling , more so purple added a mystery. Now Yixing purple clay teapot , purple crafts , purple discoloration Cicada , color kettle , purple vase , purple mural , purple flower pots , purple sculpture , purple and purple decorations tea sea . Have developed a unique style features complete .

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glow in the dark dye luminous and fluorescent

Luminous powder and phosphor are the two products, but it was also considered to be luminous phosphors . Luminous hair is because it is fluorescent , so many people also called phosphors.
Luminous : absorbance STORING a self-emitting light-emitting materials , that is, can shine a luminous material called luminous in the dark , it is divided glow in the dark materials luminous powder , luminous efficiency is short , there is a radioactive luminous , but they are a kind of glow in the dark material .
Phosphor Category: photoluminescent phosphors, phosphor fluorescent high pressure mercury lamp , fluorescent low-pressure mercury lamp phosphors , fluorescent phosphors , trichromatic fluorescent lamps , etc. . The following details about one of the long-lasting luminous powder luminous powder :
Long-lasting luminous main technical parameters:
1 initial brightness : light pink under certain brightness (1000LUX), detection equipment at 0 brightness values ( typically 3 seconds after the quench ) moments . photoluminescent film pink around 20000-25000 . Since the initial rapid reduction sad moment , capturing moments error greater impact on the general brightness with one minute to more appropriate time . Highlighting powder is generally 3500 (med/m2) above , the glitter around 2800 , Cape glitter around 2300.
2 luminous colors : yellow green luminous , luminous red , orange luminous light , orange light luminous powder , luminous light blue , sky blue light luminous , luminous purple.

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Uses range Editor

First, the backlight applications: 

All kinds of electric computers, laptops, handheld game consoles, telephones, electronic organizers, 

electronic dictionaries, audio equipment, control panels, microwave oven control panel, fax machines, 

copiers, watches ...... and so on. 

Second, the auto industry: 

Automotive instrument panel, glow in the dark material‍ warning lights, vehicle exteriors, decorative door bar, third brake light 

...... and so on. 

Third, the architecture and interior applications: 

Elevator floor marking, labeling instructions escape, decorative wall lights, night landscape 

decorative building interiors. 

Fourth, security, life-saving: 

Night police, traffic police wearing cold warning clothing, safety signs at night, lifesaving 

instructions, ships, docks, etc. 

Fifth, military and aerospace applications: 

Military map backlighting, backlit instrumentation, airport runways at night riverboat instructions, 

instructions nighttime identification, gravel for gardens‍ ground guide. 

Six, advertising goods: 

Merchandising, application of the campaign trail, election propaganda, fleet campaign, advertising 

brochures applications. 

Seven, toys, gifts: 

Various sources toys, light frame, EL photo, Valentine's cards, badges and other consumer product 

applications. 

Eight, public places of business equipment, machinery: 

Bus stop, public phone booths, glow in the dark stones‍ coin-operated drink machine on the bus route licensing ...... etc.