基于小角X散射的生物柴油/柴油颗粒物结构的分析

An Analysis on the Structure of Particulates from Biodiesel / Diesel Fuels Based on Small-angle X-ray Scattering

采用同步辐射的小角X射线(SAXS)研究了常温常压下柴油(B0)、生物柴油(B100)及其调和油(B50)燃烧后生成颗粒物的结构特征。根据3种不同燃油的散射强度曲线,用Porod曲线、Guinier曲线分析了颗粒物的回转半径、平均粒径和平均界面厚度。结果表明:生物柴油和柴油的最大散射强度出现在小散射角范围内,随着生成生物柴油比例的增大,散射强度增大。B0、B50和B100的回转半径分别是18.5、13和10nm;B0、B50和B100的平均直径分别是48nm、34nm和26nm。3种燃油的Porod曲线都呈负偏离,说明颗粒物存在界面层。测量结果与扫描电镜测试一致。

The structural features of the particulate matter （PM generated by the combustion of diesel （B0） and biodiesel （B100） and their equal portion blend （B50） at normal atmospheric temperature and pressure are studied by using small-angle X-ray scattering （SAXS） with synchrotron radiation.Based on the scattering intensity curves of three different fuels,the gyration radius,mean diameter and average interface layer thickness of PM are analyzed by Porod and Guinier curves.The results show that the maximum scattering intensity of biodiesel and diesel appears in small scattering angle range,and with the increase of biodiesel proportion,the scattering intensity rises.The gyration radius of PM from B0,B50 and B100 are 18.5nm,13nm and 10nm respectively,and the mean diameter of PM from B0,B50 and B100 are 48nm,34nm and 26nm respectively.All Porod curves of three different fuels show negative deviation,meaning the existence of interface layer in PM.The measurement results agree with that by scanning electron microscopy.