How does Fluorescence work?

When light waves hit the molecule, a photon is absorbed and gives the system energy, which promotes an electron from the ground state (S0) to an excited state (Sn). There are a few processes the molecule can then undergo (Figure 2), but the ones relevant here are vibrational relaxation, internal conversion and, of course, fluorescence. Figure 2: A simplified Jablonski diagram showing the energy levels in a molecule and the different energy processes involved for flu

What is Fluorescence?

Fluorescence and luminescence in everyday vernacular are often used interchangeably, but fluorescence is a type of luminescence, specifically a type of photoluminescence. Other types of luminescence include phosphorescence, also a type of photoluminescence, and chemiluminescence. As the prefix photo- suggests, light is a key factor for photoluminescence, in this case, fluorescence, to occur. Simply put, a molecule can absorb a photon of light and therefore its energy, and then reemit a photon of lower energy and higher wavelength. The emitted light is fluorescence or fluorescent light. Why does Fluorescence occur? To understand why fluorescence occurs, a brief understanding of the quantum mechanical make-up of a molecule is needed. An atom is made up of a net positive nucleus, which holds in place negative electrons. The electrons are held in discrete energy levels. A system will always favour the lowest energy state and so when atoms combine to make molecules, they do so because this lowers their energy and makes them more stable. When molecules form, new energy levels, known as orbitals, are formed that the electrons can exist in. For each atom or molecule, the energy levels are certain and discrete, and the system is said to be quantised.

What are Fluorescent Pigments and how do they work?

Pigments that can be stimulated by light to give brighter and more brilliant colours than conventional pigments are known as fluorescent pigments. Often, it is UV light that is responsible for this brilliance, so these pigments can also be known as UV fluorescent pigments. When an abundance of UV light is present, for example in a blacklight, they will be seen as bright and eye-catching colours. If the same eye-catching advantages are wanted without the use of a blacklight, pigments that are stimulated by daylight are needed. What are Daylight Fluorescent Pigments? Daylight Fluorescent Pigments (DFPs), such as the Aurora SRA and Aurora AQA ranges, are pigments that are stimulated by daylight to fluoresce, giving bright colours that can be used in a variety of different applications. They consist of fluorescent dyes encapsulated in resins or polymers to create fluo

A pigment is a substance that makes an object color.

A pigment is a substance that makes an object color. Pigments are soluble and insoluble, inorganic and organic. Inorganic pigments are generally mineral substances. Human beings have long known that using inorganic pigments, using colored soil and minerals, paint and smear the body on the rock walls. Organic pigments are generally derived from plants and marine animals such as alizarin blue, Garcinia and ancient Rome's purple from shellfish.

The influence of the dispersion of pigment on the paint

In the use of coatings, people often encounter problems of flocculation, lack of color or transparency, poor rheology, or poor stability, all of which are closely related to the lack of adequate dispersion of the pigment. In pure theory, [ well dispersed " it means that each pigment particle in the system is completely dissolved in the flocculation state, that is, each pigment particle is wrapped by a thin layer of lacquer or solvent. In fact, however, it is difficult to achieve. Then, what is the effect of pigment dispersity on the properties of coatings? 1, gloss: if the pigment is best dispersed, this can directly improve the gloss. In principle, the luster is determined by the properties of the base. Adding the necessary pigment can only have an adverse effect on the gloss: if the pigment is not best dispersed, some pigment agglomeration particles will have an adverse effect on the surface evenness, thus reducing the gloss due to the diffuse of light. 2. Patience: weather resistance and chemical resistance will also be determined by the choice of paint base. Inadequate dispersion of pigment particles will also reduce patience. The pigment particles on the surface provide an attack point for chemicals and climatic factors. On the other hand, if the correct selection of the pigment is best dispersed, it can only improve the durability of the coating system, for example, by reflecting (TiO2) or absorbing UV radiation (iron oxide red) to improve the weatherability. Proper dispersion of pigment or pigment can also improve the chemical resistance of lacquer base.

The main performance and evaluation method of pigment for Color Masterbatch

The selection of pigment for Color Masterbatch should not only refer to the related technical standards of ink and paint, but also the processing and application needs of the products, such as heat resistance, resistance to migration, weather resistance and solvent resistance, as well as the interaction with polymers and additives. The pigment chosen is not only brilliant, but also durable and durable. The main properties and evaluation methods of pigments used for masterbatch are described below. 1. the coloring power of pigments is the amount of pigment required for a certain color product, expressed by the percentage of the standard sample's coloring power. That is to take 1g standard sample, add Ag white pigment, and mix it into a certain color mixture. Then take the 1g to test the pigment, add white pigment, until the standard light source color is the same as the standard sample mixture, the A color pigment is Bg, then the pigment's coloring force I is I=B/A× the coloring force of the 100% pigment is not only related to its properties, but also related to the degree of pigment dispersion. The degree of dispersion mainly refers to the degree of refinement of the pigment, the greater the degree of dispersion, the stronger the coloring power, but there is a maximum value. The above is the standard for the coloring force of ink and paint. The standard of standard sample and sample is suggested to be added to the standard sample and sample, which is measured by the ratio of the same depth, that is, A is the amount of resin added to the standard color plate, and the B is the added tree fat when the color depth is similar to the A color.