Yearly Archives - 2024

Generation and rate constant of phosphorescence

Phosphorescence is another important type of excited state radiation transition, which is the radiation released when excited state molecules lose their lives to low energy states with different multiplicity. Usually observed phosphorescence is the radiation released when the first excited triplet state (Ti) transits to the ground state (S) (Kasha rule). Generally, phosphorescence is much weaker than fluorescence, because the T-state emitting phosphorescence is usually not easy to directly absorb photons from the S-state, and the T-state is mainly formed...

Practice of polyester strontium aluminate long afterglow fluorescent coating

Raw material: unsaturated polyester resin Strontium aluminate phosphor Other additives solvent accelerating agent solidifying agent [Preparation method] Fluorescent powder, solvent and other additives are added to unsaturated polyester resin according to a certain proportion, which is stirred evenly for later use, and curing agent is added according to a certain proportion when the film is formed. [Characteristics ] The coating has high fluorescence efficiency and long aging, and has the advantages of good adhesion, high shear strength and so on. (1) The brightness of unsaturated polyester resin coating...

What are the preparation methods of luminous plastics?

The preparation of luminous plastics usually varies according to the addition method of luminous agent and the production process of plastic products or materials. The main methods are direct addition, masterbatch addition and in-situ polymerization addition. ① Direct Addition Method Direct addition method is the simplest method. The plastic luminous agent powder is directly mixed with the resin. In order to mix and disperse evenly, it is best to mix with the powdered resin. For example, when the resin is polypropylene...

A making method of rare earth photoluminescence safety paint

Raw material: Styrene-acrylic emulsion,rutile titanium dioxide,talcum powder,mica powder,luminous pigment,glycol pigment dispersant (agent),defoamer,Thickener Preparation method Firstly, measure the emulsion, and then put a certain amount of styrene-acrylic emulsion into a beaker; Then, all kinds of additives are measured separately, and then the additives except defoamer are put into another beaker, fully stirred and mixed into mixed additives; Add defoamer into the mixed additives, mix evenly, slowly add people into half of the emulsion, and continue to stir for 10min for later use; Putting the...

Spectral properties of luminescent materials

Fluorescence is photoluminescence, and under the action of optical radiation, fluorescent substances emit fluorescence with different wavelengths. Any fluorescent compound has two characteristic fluorescence spectra, namely excitation spectrum and emission spectrum. A fluorescence emission wavelength is selected to record the fluorescence emission intensity as a function of the excitation wavelength, and the fluorescence excitation spectrum is obtained. It reflects the relative efficiency of fluorescence caused by excitation light with different wavelengths. The excitation spectrum can identify the fluorescent substance,...

Luminous afterglow time and its measurement

An important characteristic of luminescent materials is its luminous duration. According to the duration of luminescence, luminescence can be divided into fluorescence and phosphorescence. The gap between excitation and emission of fluorescence is very short, about < 10-* s. As soon as the light source leaves, the fluorescence will disappear. Phosphorescence will emit light for a long time after the excitation source leaves. Afterglow can also be used to indicate the duration of light emission. Afterglow is defined as:...

Preparation of Epoxy Modified Alkyd Luminous Coatings

Preparation method: (1) Preparation of luminescent materials. According to the molar ratio of Sr, Al, Pu and Dy of 1∶2∶0.02∶0.02, accurately weigh Sr (NO3), AI (NO) 3.9h, 0, Eug05, Dy203, NHHCO3,(NH),CO and flux BO, with appropriate amount. Dissolve Eu,03 and Dy,03 in HNO. Preparing a mixed solution A of Eu3 * and Dy3 *; Then Sr(NO3)3 and Ali (NO3) 3.9h, 0 are dissolved together in distilled water to prepare solution B; Then, the solution A and the solution B are...

Preparation of long afterglow luminescent flame retardant coatings

Preparation method The components except the long-afterglow luminous powder are mixed evenly with a stirring device, and then the long-afterglow luminous powder is added in the case of slow stirring, stirring for a period of time and then quickly stirring until uniform. Raw material compatibility The mass proportion range of each component of this product: high chlorinated polyethylene (30%)20~40; Chlorinated rubber 1 ~ 5; 70% chlorinated paraffin 3~8; 50% chlorinated paraffin 2 to 6; Antimony trioxide 2~5; Dispersant 0.1 ~ 0.5; Fumed...