不同炭化条件下竹炭的电子顺磁共振

Carbonization Mechanism of Bamboo by Means of Electron Spin Resonance

利用电子顺磁共振(ESR)技术对竹材热处理至900℃的炭化机理进行了研究。结果表明:(1)600℃左右是竹材炭化的一个非常重要的热处理温度。低于600℃时,为竹材炭化的热解阶段;高于600℃时,为竹材炭化的过渡阶段,并且产生非常显著的硅效应。(2)竹材的热分解历程主要表现为自由基反应。(3)竹炭中的水分和炭化气氛对自旋中心的性质和弛豫机制都产生了比较明显的影响,并且在不同的炭化阶段产生的影响不同。

Carbonization mechanism of bamboo was investigated by means of Electron Spin Resonance （ESR）. The results show： （1） Around 600 ℃ is a key carbonization temperature for bamboo. Below 600 ℃, the first stage, bamboo mainly experiences the thermal decomposition. Above 600 ℃, the second one, the conduction of bamboo charcoal is changed into semiconductor from insulator. Obviously silicon effect is observed in the transition stage. （2）Thermal decomposition of bamboo is mainly concerned with radicals from the decomposition of hemicellulose, cellulose, and lignin in bamboo. （3）Moisture and the carbonized atmosphere have effects on the properties and relaxation mechanism of spin centers.