分步水热热解合成单分散碳微球

Synthesis of carbon microspheres via two-step hydrothermal-pyrolysis method

以水溶性淀粉为原料,经分步水热处理和高温热解制备出粒径范围为0.1~0.4μm的碳微球,分别采用扫描电子显微镜(SEM)、X射线衍射(XRD)仪和傅里叶变换红外光谱仪(FT-IR)对碳微球的形貌、晶体结构和化学键进行分析,并探讨了反应条件对碳微球形貌和结构的影响。结果表明,第一步水热反应中保温温度和时间对碳微球的分散性有重要的影响,在保温温度为160℃,时间为2h的工艺条件下获得的碳微球表现出最优的分散性;第一步水热后取出的部分溶液与第二步水热中新加溶液的体积比、第二步水热中新加溶液的浓度是影响碳微球平均粒径和产量的重要因素,即平均粒径和产量随着溶液体积比的减小而增大,而随新加溶液浓度的增大而增大;但上述工艺参数对碳微球的晶体结构和化学键影响甚小。

Using starch as carbon source,carbon microspheres with diameters from 0.1 to 0.4μm were fabricated by two-step hydrothermal method and high temperature pyrolysis method.The morphology,crystal structure and chemical bonds of prepared microspheres were characterized by scanning electron microscopy,X-ray diffraction and FT-IR spectrum,and the effects of process conditions on the morphology and structure were discussed.The results indicated that the first-step hydrothermal temperature and time had important effects on the dispersion of final carbon microspheres.The final carbon microspheres possessed the best dispersity at 160℃for 4 h.The important influences on the particle size and production of final carbon microspheres included the volume ratio between the solution which was taken out in the first-step hydrothermal reaction and the added solution in the second step and the added solution concentration.With the dicrease of volume ratio or the increase of added solution concentration,the average particle size and production increased simultaneously.The above process parameters showed insignificant influence on crystal structure and chemical bonds of microspheres.