辐照气氛对异丙氧基杯[4]冠-6辐解的影响

异丙氧基杯4]冠-6(1,3-交替-25,27-二(2-丙氧基)杯4]芳烃-26,28-冠-6, 简称BPC6)对高放废液中的放射性Cs离子具有很好的选择萃取性能, 然而在萃取过程中BPC6 会受到强辐射场辐照, 所以有必要研究其辐射稳定性. 本文应用气相色谱(GC)、傅里叶变换显微红外(Micro-FTIR)和核磁共振(NMR)谱等手段分析了BPC6 固体分别在O₂和N₂气氛下的γ辐照效应. 结果表明, 当剂量为1 MGy时, O₂气氛下BPC6 的辐解率明显高于N₂(分别约为10.4%和2.5%), 而且气体辐解产物也有很大差异, 在O₂气氛下主要为H₂、CH₄、CO和CO₂,而在N₂辐照气氛下还有C₂H₄、C₂H₆、C₃H₆和C₃H₈等产物. 通过综合分析气体与固体辐解产物, 我们提出BPC6在不同气氛下具有不同的辐解途径, 这将为BPC6 萃取体系的辐射效应研究提供新的方法与思路, 加深对其辐解机理的认识.

Influence of Atmosphere on the Radiolysis Products of BPC6 under γ-Irradiation

Bis(2-propyloxy)calix4]crown-6 (BPC6) is an effective separation agent for the removal of cesium from high-level liquid wastes, because of its high selectivity and coordination capacity toward cesium ions. BPC6 will be exposed to ionizing radiation generated by radionuclides during the treatment of high-level liquid nuclear wastes, so it is necessary to investigate the radiolysis mechanism of BPC6 under γ-irradiation conditions. In this work, the radiolysis products including the gaseous and solid products of BPC6 solid were systematically assessed using gas chromatography (GC), micro Fourier transform infrared (Micro-FTIR) spectroscopy, and nuclear magnetic resonance spectroscopy. The radiolysis ratio for BPC6 in an O₂ atmosphere (approximately 10.4%) was significantly higher than that in an N₂ atmosphere (approximately 2.5%). The main radiolytic gas products of BPC6 under O₂ were H₂, CH₄, CO, and CO₂, while those under N₂ were H₂, CH₄, CO, CO₂, C₂H₄, C₂H₆, C₃H₆, and C₃H₈. Finally, a mechanism for the radiolysis of BPC6 under different atmospheres was suggested, in terms of the gas and solid radiolytic products. This work will be of significant help in understanding the degradation mechanism of the BPC6 extraction system.