Nucleus leakage happened in some place, rendering this place a forbidden area for lives. This is a scene people frequently meet in science movies.
In these movies, traditionally the reactions to the leakage of the heroes are sending checking robots, examining by helicopter and even running through the block in flash under some circumstances. But there is a novel option now.
Prof. ZHANG Guoqing from National Research Center for Microscale Physical Science of University of Science and Technology of China (USTC) of the Chinese Academy of Sciences, and his team members, recently found that polymethylmethacrylate (PMMA) and polyvinyl chloride (PVC) can release acidic substance under γ radiation, whose amount is proportional to the radiation intensity.
After adding acid-base indicators like Quinoline blue fluorescent molecules, the amount of the acidic substance can be measured by monitoring the ratio of different fluorescence intensities. This feature enabled the team to develop a new kind of γ-radiation intensity sensor, which is in the form of a membrane. With the increasement of γ-radiation intensity, the film gently turns red, making the distinguishment of radiation intensity quick and easy.
In addition, the researchers carried out experiments to justify their explanation for this phenomenon. The results turned out to be that additional acid cause color changes similar to γ-radiation. Additional base can also help the irradiated film to return to its initial stage. The quantum chemistry simulating calculations of Quinoline molecule orbitals coincided with their experimental outcome. These results confirmed the accuracy of their hypothesis.
Being cheap, reliable and durable, this film sensor is expected to work in extreme situations. It can be thrown into the nucleus leakage affected area and help people to map the distribution of radiation intensity remotely, which is more than significant in protecting people and their property.
The study was published in ACS Applied Materials &Interfaces.
Schematic Illustration of Proton Generation in PMMA or PVC under γ-radiation and Visualization of the Released Protons via Fluorescence Sensing (Image by PEI Bin et al.)
(Written by LIU Zige, edited by LI Xiaoxi, USTC News Center)
