正辛醇的γ辐照稳定性及辐解产物分析

Radiation Stability and Analysis of Radiolysis Product of 1-Octanol

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100kGy以下辐照后化学结构未发生变化,而吸收剂量增至300kGy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(600kGy)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.

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.