正辛醇的γ辐照稳定性及辐解产物分析

在高放射性废液后处理的萃取工艺中, 正辛醇被认为是具有应用前景的稀释剂之一, 而研究其γ辐射效应对指导其实际应用具有重要意义. 本文对N2环境下γ辐照后的正辛醇进行了紫外-可见(UV-Vis)光谱和傅里叶变换红外(FTIR)光谱研究. 结果表明正辛醇在100 kGy以下辐照后化学结构未发生变化, 而吸收剂量增至300 kGy时有羰基化合物生成. 通过色谱(GC)和色质联用(GC-MS)进一步分析了高剂量(600 kGy)辐照后正辛醇的气体及液体辐解产物, 发现主要气体产物为H2, 并伴有微量的CO2和CH4; 主要液体产物为正辛醛, 其占未辐解正辛醇的质量百分含量小于1%, 并伴有少量正庚烷和8-羟基十五醇. 对辐照后正辛醇的化学结构及辐解产物的分析表明, 正辛醇在氮气下经γ辐照后, 主要发生α碳原子上的C—H键断裂,并伴有β碳原子上的C—C键断裂. 此外, 抽氢反应也是正辛醇辐解的重要途径.

Radiation Stability and Analysis of Radiolysis Product of 1-Octanol

1-Octanol is a promising solvent for the extraction of high-level radioactive waste from nuclear fuel reprocessing and a study of radiation effects on 1-octanol is necessary before its industrial application in high-radiation environments. In this work, UV-Vis spectroscopy and Fourier transform infrared (FTIR) spectroscopy were used to investigate the radiation stability of 1-octanol in nitrogen for the first time. Results indicate that 1-octanol is chemically stable at a dose of 100 kGy and that compounds containing a carboxyl group are formed at a dose of more than 300 kGy. The major radiolysis products of irradiated 1-octanol at 600 kGy were analyzed using gas chromatography(GC) and gas chromatography-mass spectrometry(GC-MS). Hydrogen was formed as a major gaseous product and small amounts of carbon dioxide and methane were also found. The dominant liquid product was 1-octanal and its mass percent was less than 1% in the 1-octanol solution. Small amounts of heptane and 8-pentadecanol were also produced. Analysis of the chemical structure and radiolysis products of the irradiated 1-octanol suggests that during gamma irradiation in nitrogen, C—H bond breakage at the α-carbon in 1-octanol is the dominant reaction and the C—C bond at the β-carbon can break as well. Additionally, hydrogen abstraction reactions occur between the primary H-atom radical produced during irradiation and 1-octanol.