【摘要】 基于透射电镜（TEM）、傅里叶变换红外光谱（FT-IR）和X射线光电子能谱（XPS）试验对不同掺混比例与不同负荷下的聚甲氧基二甲醚(PODE_2-4)/柴油混合燃料排气颗粒物的理化特性变化规律进行研究.TEM与分形理论分析表明,当PODE_2-4掺混比例增加或负荷减少时,颗粒物的整体尺寸变小,排列更紧密,分形维数变大.FT-IR分析发现,当PODE_2-4掺混比例或负荷增加时,当量峰高比比值减少,颗粒物表面脂肪族碳氢官能团相对含量降低.XPS试验表明,随着PODE_2-4掺混比例的增加或负荷的减小,颗粒物表面的氧、碳元素物质的量比与碳原子杂化比比值增加,羟基、羰基以及总含氧官能团含量增大.结果表明:PODE_2-4掺混比例的增加和负荷的减小影响颗粒物的纳观结构和氧化活性,使其更易于被氧化,有利于颗粒物捕集器的再生.更多还原

【Abstract】 Physicochemical characteristics of particulate matter（PM） of polyoxymethylene dimethyl ethers(PODE_2-4)/diesel blended fuel were investigated under different blending ratios and engine loads by using measurements of transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FT-IR） and X-ray photoelectron spectroscopy（XPS）. TEM measurement results show that when the PODE_2-4 blending ratio increases or the load is reduced,the overall size of PM becomes smaller and the arrangement is closer. Fractal theory analysis show that the fractal dimension of the PM becomes larger as the PODE_2-4 blending proportion increases or the load decreases. FT-IR analysis indicates that the equivalent ratio of peak to height of IC—H/IC=C ratio and the aliphatic C—H functional group on the surface of the PM decrease with an increase in PODE_2-4 concentration or engine load. The XPS results indicate that with the increase of the PODE_2-4 blending ratio or the reduction of the load,the n（O）/n（C）ratio,sp³/sp² ratio and the contents of C—OH,C=O and total oxygen-containing functional groups on the surface of the PM increase. The results show that the addition blending of PODE_2-4 or the decrease of load affects the nanostructure and oxidation activity of the PM,making it easier to be oxidized,which is beneficial to the regeneration of particulate filter.更多还原