Phosphorus and Nitrogen Codoped Carbonized Polymer Dots with Multicolor Room Temperature Phosphorescence for Anticounterfeiting Painting

Abstract

Visible spectral afterglow materials offer unprecedented potential for a myriad of applications due to their long luminescence characteristics, but it is still insufficient to prepare matrix-free materials with multicolor afterglow including the blue color. In this study, we successfully developed phosphorus and nitrogen codoped carbonized polymer dots (CPDs) with multicolor room temperature phosphorescence (RTP) including the blue color by microwave-assisted chemical reactions under different reaction time. After ceasing UV light, all four prepared CPDs were able to emit vivid RTP with a maximum absolute phosphorescence quantum yield (QY) of 59.41% and a maximum lifetime of about 1 s (yellow CPDs). With the increase of microwave reaction time, the RTP color of CPDs showed a gradual blue shift from yellow to blue. The reason why the RTP color of CPDs showed a gradual blue shift was the decrease of CO units as the extension of the microwave reaction time. In view of their fascinating multicolor RTP properties, potential applications of the four CPDs in the field of anticounterfeiting painting were presented and demonstrated. This work would inspire other researchers to enrich multicolor afterglow materials.

Yellow-Emissive Carbon Dots with Long-Lifetime Room-Temperature Phosphorescence for Information Encryption and Bioimaging

“…As shown in Figure c, the emission wavelength varied from 420 to 472 nm with excitation wavelengths in the range of 280–420 nm, and the highest emission intensity at 415 nm was obtained with 360 nm excitation. The excitation wavelength-dependent behavior may derive from multiple triplet emission centers in MgCDs-500. , Moreover, the FL emission colors with different excitation wavelengths are calculated in the CIE chromaticity coordinates (Figure S2 and Table S1), which demonstrate that the FL emission color of MgCDs-500 varied from blue to cyan with excitation wavelengths ranging from 280 to 420 nm. Correspondingly, the excitation and emission contour figure of MgCDs-500 (Figure d) described that the strongest RTP emission is obtained at 527 nm, which is consistent with the luminous color of RTP.…”

Evolution and fabrication of carbon dot-based room temperature phosphorescence materials

“…Realizing the final application is the value of a material. 110,126,127,[144][145][146][147][148][149][150] information encryption, 113,115,118,119,121,123,128,[151][152][153][154][155][156][157][158][159][160] sensor detection, 114,124,129,130,147,[161][162][163][164][165][166][167][168][169][170][171][172][173][174] LEDs, [175][176][177][178]…”

“…It allows significantly increased time to visualize cell states, enables speedy detection, and also facilitates bioimaging and detection. Generally speaking, the RTP material based on CDs possesses huge application prospects in the field of anti-counterfeiting, 110,126,127,144–150 information encryption, 113,115,118,119,121,123,128,151–160 sensor detection, 114,124,129,130,147,161–174 LEDs, 175–179 biological imaging, 134,180,181 logic gates, 133 fluorescent ink 112,182–184 and other fields 116,117,122,185–195 with the properties of DF, TADF, long afterglow life and adjustable afterglow color.…”

Preparation of Self-Healing Anthocyanidin-Containing Thermochromic Alginate Ink for Authentication Purposes

“…Fabricating innovative materials with thermochromic characteristics is therefore crucial to the development of cutting-edge authentication devices free of background interferences . Recently, anticounterfeiting ink made from a variety of thermochromic materials such as polymer dots and supramolecular hydrogels, has been reported. , Thermochromism is a temperature-triggered reversible phase transition between two different color states of different wavelengths. The development of temperature-induced chromic polymer ink has been the focus of recent studies because of their remarkable stability and colorimetric qualities .…”