Luminescent Coating Research Articles

Natural Light Rechargeable Night Peal-like Coatings for Expressway

Traditional roadway lighting is intended to provide safe guidance for drivers and pedestrians, but the large-scale application of roadway lighting has resulted in significant energy consumption and light pollution. However, road markings prepared by luminous coating are a kind of multi-functional road marking that can meet the needs of highway lighting at night and save energy. Here, CaAl2O4:Eu2+,Nd3+,Gd3+ blue long-afterglow phosphor is obtained by the high-temperature solid-state method, and the blue luminescent coating is synthesized by the blending method. The phase composition, microscopic morphology, luminescence properties and water resistance of the phosphor and luminescent coatings are characterized. The best components and processes of the luminescent coating are explored to meet the application of an expressway. Considering the afterglow’s performance, the optimal calcination temperature of the phosphor is determined to be 1300 °C. The afterglow of the phosphor can be over 8 h after 2 h of daylight excitation. The addition of 1.25% SiO2 to the luminescent coating improves the uniformity of the components, and the incorporation of 3.5% CaCO3 improves the denseness of the coating. When the coating thickness is 0.8mm, the luminescent coating can achieve the best luminous effect. After 120 h of immersion in water, the afterglow intensity of the luminescent coating reduced to 70% of the original, which has excellent water resistance. The blue luminescent coating with the addition of appropriate amounts of CaCO3 and SiO2 improves the dispersion as well as the densification of the components in the coating to achieve the best luminescent effect. In the Shenyang area, different weather conditions (cloudy, sunny, rainy) have no significant effect on the afterglow performance of the luminescent coatings, all of which can achieve over 5 h of afterglow and are suitable for expressways.

Sunlight-Activated Long Persistent Luminescent Coating for Smart Highways

With the whole society’s demand for intelligence, the smart highway has become the inevitable trend of road development. Luminescent road marking made of long persistent luminescent coating is a new type of functional marking that is designed with long afterglow luminescent material as the raw material and has many features such as safety, beauty and energy saving. Here, SrA12O4:Eu2+,Dy3+ green long afterglow phosphors were prepared using a high-temperature solid state method. The green phosphors obtained at 1350 °C have two traps with a shallow trap depth of 0.66 eV and a deep trap depth of 0.8 eV. The green afterglow can be seen in the dark for more than 8 h after sunlight excitation for 2 h. The green long persistent luminescent coatings were synthesized using the blending method. The uniformity of each component can be improved by adding 1.25% SiO2 into the luminescent coatings. The addition of 3.5% CaCO3 will improve the compactness of the coatings and reduce water absorption. After soaking in water for 120 h, the afterglow intensity of the coating decreases to 76% of the original, showing good water resistance. After daylight excitation in different weather conditions (cloudy, sunny, rainy), the afterglow can reach more than 5 h; therefore, it can be applied to a smart highway.

Copper Iodide Cluster Incorporated Luminescent Organic-Inorganic Hybrid Coating Exhibiting Both Corrosion Protection and Antibacterial Properties.

A photoluminescent organic-inorganic hybrid coating is synthesized by the incorporation of an emissive Cu4I4 core into a cross-linked coating network through Cu-P coordination bonds. The hybrid coating not only emits strong yellow emission under UV-light irradiation but also exhibits corrosion protection of the metallic surface. Moreover, bactericidal properties are studied that were first reported for Cu4I4-based hybrid light-emitting materials.

Synthesis, experimental and theoretical studies of two aryl-azo derivatives clubbed with 2-acetylphenol and their application as novel luminescent coatings with high anticorrosion efficiency

In the current study, novel luminescent coatings and corrosion inhibitors were designed, prepared, and characterized using various spectroscopic techniques. Two aryl-azo derivatives linked with 2-acetylphenols were designed and synthesized through a simple condensation reaction. Luminescent coatings offer a wide range of applications. In azo-dye molecules, the existence of heteroatoms and π-electron systems is critical for their color and ability to adsorb on metal surfaces and other adsorbents. The quantum calculations, corrosion inhibition, and photoluminescence properties of two simple azo derivatives with various substitutions are evaluated and discussed. Surprisingly, their powders emitted white light from a single component. Furthermore, the impact of incorporating electron-donating or withdrawing groups on the molecular packing and emission properties has been shown. The photoluminescence measurements confirmed that the derivative with an electron-withdrawing group has molecular aggregation capable of generating white emission from a single chromophore. The investigated compounds displayed significant inhibitory efficiency (ex. 92%) and played an important role in preventing C-steel corrosion in 2 M HCl. The electrochemical experiments confirmed that the presence of these azo derivatives reduces corrosion current densities, double-layer capacities, and corrosion rate while improving charge transfer resistance. The outcomes show that the computational calculations are rather accurate in matching the experimental data. As a result, the molecules under study may give a straightforward method for obtaining the interesting single-component white emission from a simple material. • A Fries rearrangement was employed to construct acetyl-4-(4-bromo/methyl-phenylazo)phenols for the first time. • May serve as a luminescent coating for potential commercial applications. • The tested azo compound retard C-steel corrosion rate. • AFM and DFT studies support protecting of C-steel against acid corrosion.

Multi-Functional Luminescent Coating for Wood Fabric Based on Silica Sol-Gel Approach.

Environmentally friendly protection coatings have obtained increasing attention for their use in wooden materials, which can be destroyed easily when exposed to outdoor environments. A series of silane sol coatings coordinated with Eu3+ was prepared by hydrolyzing silane compounds. The obtained luminescent coating with three-dimensional net structure showed excellent optical, anti-ultraviolet aging, and thermal stability. The hybrid silane-modified compound coating was well-distributed on the wood by Si–O bonds to prevent its removal. The compound coating could stave off the decomposition of wood by converting ultraviolet light into red light and a charring action can endow the wood with thermal stability at high temperature, demonstrating the improvement of fire resistance and radiation residence following prolonged exposure to ultraviolet light, proving its excellent anti-ultraviolet aging properties.

Engineering of luminescent graphene quantum dot-gold (GQD-Au) hybrid nanoparticles for functional applications

Graphene quantum dots (GQDs) possess excellent optical and electrical properties that can be used in a wide variety of application. Synthesis of hybrid nanoparticles with GQDs have been known to improve the properties further. Therefore, in this method, graphene quantum dots –gold (GQD-Au) hybrid nanoparticles were synthesized using GQDs which reduces HAuCl4.3H2O to Au nanoparticles on its surface at room temperature. The GQDs with self-passivated layers were synthesized by microwave assisted hydrothermal method using glucose as a single precursor. The synthesis process does not involve the use of harmful chemicals. The whole synthesis process of GQD and GQD-Au hybrid nanoparticles takes only five minutes. The synthesized GQDs have been extracted using citrate in order to increase the stability of the hybrid nanoparticles for up to four weeks. The size of the synthesized GQD-Au hybrid nanoparticles is in the range of 5–100 nm and were found to be luminescent under UV-A illumination. The merit of the following method over other synthesis techniques include its rapidity, ease of preparation, and no requirement of elaborate synthesis procedures and/or harmful chemicals. The GQD-Au hybrid nanoparticles can be used in several applications such as luminescent coatings for glass and windowpanes for automobiles, etc. The reducing property of GQDs can further be utilized for the reduction of various metal salts (AgNO3) and organic dyes (methylene blue and methyl orange).. It presents a method/protocol-development of the luminescent GQD-Au hybrid particles of size ~ 5–100 nm.. The GQD-Au hybrid particles find potential applications in luminescent coating applications.

Application and Research on Luminescent Coating in Interior Design

As a new-type material, luminescent coating has received increasingly extensive application in modern life. The varieties of luminescent coatings gradually increase with the progress of science and technology, of which each kind of them shows its own unique property. This thesis researched on the different properties of various luminescent coatings so as to make them into rational use on the interior interface, thus achieving the more appropriate and safer use in interior design for the sake of beautification space, economizing and environmental protection.

Novel Functional Coating: Luminescent Coating

The luminescent coating as one of the special functional coatings of the 21st century has attracted a great deal of attention recently. Luminescent coating is divided into three categories: fluorescent coating, self-luminous coating, energy storage luminescent coating. The article briefly summarizes their principles and luminous characteristics. And mainly reviews the present research situation, the future development tendency and their widely applications both at home and abroad.

Improvement of the Coating Formulation in Luminescent Photoelastic Coating Method

For overcoming the limitation of a low signal-to-noise ratio (SNR) in practical applications of luminescent photoelastic coating (LPC) method, a new LPC configuration applied in the LPC method is presented. Based on a brief introduction on the principle of molecular luminescence, the intensity formula for the new LPC is derived according to the theory of photoelasticity. Through the comparative analysis with the existing coating configurations (dual-layer coating and single-layer coating), the feasibility of this new LPC used in the LPC method for experimental strain analysis is proved theoretically, and the signal intensities of the LPC method can be increased by over two times.

Factorial Design Experiment to Analyze the Response of a Luminescent Photoelastic Coating

A luminescent photoelastic coating is a relatively new technique to measure full-field surface strain and determine principal strain directions that has many potential applications in engineering. Generally, luminescent photoelastic coating technology uses an in situ strain gage measurement to calibrate the detected optical response to maximum shear strain. This calibration requires the determination of two coating parameters: the polarization efficiency and the coating characteristic. A better understanding and modeling of these two parameters, particularly the polarization efficiency, will enable a simpler a priori calibration and greater measurement accuracy. This paper presents a factorial design experiment that assesses the effect of four factors on the optical strain response of an luminescent photoelastic coating. The factors examined were substrate reflectance, luminescent dye concentration, absorption dye concentration and cure time. Results show the polarization efficiency is strongly correlated with the emission anisotropy of the coating. When the polarization efficiency is modeled as the measured emission anisotropy, the two most significant factors are the substrate reflectance and the luminescent dye concentration. Absorption dye concentration and reflectance-luminescence interaction are minor but significant effects. The most significant tested factors in modeling the coating coefficient are absorption dye concentration and substrate reflectance. The resulting uncertainties for the polarization efficiency and coating characteristic are 1.3 and 3.7%, respectively.

Characterization of a New Luminescent Photoelastic Coating

Characterization of a New Luminescent Photoelastic Coating

An Optical Fiber Sensor for the Detection of Germicidal UV Irradiation Using Narrowband Luminescent Coatings

A narrowband luminescent coating for germicidal 254-nm ultraviolet optical fiber sensors has been developed. A mixture of phosphor and epoxy is used for this coating. The luminescent-clad sensing principle uses a fiber, which has had its cladding and jacket both removed, and a photoluminescent coating replacing the cladding. As the coating luminesces, part of the emission is coupled to the fiber core through evanescent wave coupling. The combined absorption spectrum of the phosphor and the transmission spectrum of the epoxy result in a narrow sensitivity band of wavelengths being detected, centered around 254 nm. The absorption of the 254-nm radiation incident on the coating is emitted as visible light in the optical fiber sensor. This paper describes the development and testing of this narrowband coating using a spectrophotometer to examine its responsivity, and a luminescent-coated optical fiber sensor is compared with a UV photodiode when illuminated by a UV lamp. This optical fiber sensor monitors the output of UV lamps for stabilization and control purposes.

Surface pressure field mapping using luminescent coatings

In recent experiments we demonstrated the feasibility of using the oxygen dependence of luminescent molecules for surface pressure measurement in aerodynamic testing. This technique is based on the observation that for many luminescent molecules the light emitted increases as the oxygen partial pressure, and thus the air pressure, the molecules see decreases. In practice the surface to be observed is coated with an oxygen permeable polymer containing a luminescent molecule and illuminated with ultraviolet radiation. The airflow induced surface pressure field is seen as a luminescence intensity distribution which can be measured using quantitative video techniques. Computer processing converts the video data into a map of the surface pressure field. The experiments consisted of evaluating a trial luminescent coating in measuring the static surface pressure field over a two-dimensional NACA-0012 section model airfoil for Mach numbers ranging from 0.3 and 0.66. Comparison of the luminescent coating derived pressures were made to those obtained from conventional pressure taps. The method along with the experiment and its results will be described.