A novel X-ray scintillator constructed based on stable luminescent free radicals

introduction

X-ray scintillators, as a special type of material capable of converting high-energy X-ray radiation into visible or near visible light, play an important role in fields such as medical imaging, non-destructive testing, electron microscopy, and high-energy particle detectors. With the advancement of technology, the development of high-performance X-ray scintillators has become a focus of researchers' attention. In recent years, the introduction of stable luminescent free radicals has provided new ideas for the design of high-performance X-ray scintillators. This article will introduce the research progress and application prospects of a new type of X-ray scintillator based on stable luminescent free radicals.



Characteristics of Stable Luminescent Free Radicals

Organic free genes have unique optical, magnetic, and electrical properties due to the presence of unpaired electrons. However, traditional organic radicals have poor luminescence effects and are easily affected by environmental factors, leading to deactivation. In recent years, researchers have overcome these challenges by designing and synthesizing stable luminescent free radicals. Stable luminescent radicals such as Polychlorotriphenylmethyl (PTM) radicals and Trichlorophenylmethyl (TTM) radicals, due to their first excited state (D1) and ground state (D0) being in a double line state, allow for spin allowed radiative transitions from D1 to D0, theoretically achieving an exciton utilization rate of up to 100%. This characteristic makes stable luminescent radicals have great potential in the construction of X-ray scintillators.

A novel X-ray scintillator based on stable luminescent free radicals

Research progress

Recently, a collaborative team between the School of Chemistry at Zhengzhou University and the Chinese University of Hong Kong (Shenzhen) has introduced stable luminescent free radicals from open shell luminescent materials into the design of high-performance X-ray scintillators for the first time. They utilized stable luminescent free radicals containing Au (I) complex structures to prepare a novel X-ray scintillator. This type of scintillator emits bright light under X-ray excitation, with intensity comparable to commercial scintillators, and the lowest detection limit is much lower than the detection limit required for medical scintillation examinations. In addition, the free radical scintillator exhibits excellent X-ray photostability, high thermal stability, and good processability.

Another noteworthy research is the collaboration between The Chinese University of Hong Kong (Shenzhen) and City University of Hong Kong, where they successfully synthesized a non conjugated stable free radical polymer PGTEMPO that emits red light in the solid state. This polymer achieves long wavelength luminescence through spatial interactions, providing a new approach for the design of organic luminescent radicals. The luminescence behavior of PGTEMPO is closely related to the presence of nitrogen oxygen radicals. By adjusting the polymer skeleton, its photophysical properties can be regulated.

Application of Nanotechnology

The research team at MIT has improved the efficiency of existing scintillators through nanotechnology. They increased the efficiency of the scintillator by at least 10 times, and even up to 100 times, by creating a pattern with a length scale equivalent to the wavelength of the emitted light in the scintillator material, such as a wavy ridge array. This method is not only applicable to new materials, but can also be used to improve existing materials, providing new possibilities for fields such as X-ray imaging.


application prospect 

The novel X-ray scintillator based on stable luminescent free radicals has broad application prospects in multiple fields. In medical imaging, high-performance scintillators can improve image quality, reduce X-ray dose, and thus lower the radiation risk for patients. In the field of non-destructive testing, new scintillators can achieve more accurate detection of internal defects in materials, improving detection efficiency and accuracy. In addition, new scintillators have shown great potential for applications in fields such as electron microscopes and high-energy particle detectors.

conclusion

The introduction of stable luminescent free radicals has opened up new avenues for the design of high-performance X-ray scintillators. By designing the structure of free radicals rationally and introducing nanotechnology, researchers have successfully prepared various new types of scintillators and demonstrated excellent application performance in multiple fields. In the future, with the deepening of research and continuous technological progress, X-ray scintillators based on stable luminescent free radicals are expected to play an important role in more fields and promote the sustainable development of related technologies.