柴油机排气颗粒表面特征与吸附能力分析

利用全自动比表面积与孔隙分析仪和光学接触角测量仪，分别对炭黑和柴油机排气颗粒的比表面积与孔隙以及接触角等表面特征参数进行了测量，并对炭黑和柴油机排气颗粒的分形维数和表面张力进行了计算，对比分析了炭黑和柴油机排气颗粒的吸附能力，探讨了柴油机排气颗粒表面特征参数与吸附能力之间的关系.通过检测与分析，炭黑和柴油机排气颗粒的比表面积分别为78.003和65.408m²/g，平均孔径分别为13.845和14.483nm，分形维数分别为2.5885和2.5515，在0.985s时刻的表面张力分别为51.1和56.6mJ/m²，结果表明炭黑与柴油机排气颗粒的比表面积，孔径分布，分形维数和表面张力均相似.炭黑和柴油机排气颗粒均表现了极强的亲油性，轻微亲水性.柴油机排气颗粒亲水性略强，表面更为光滑，吸附能力略低于炭黑.

Surface characteristics and adsorption capability of diesel engine exhaust particulate matter

The surface characteristic parameters of carbon black and diesel exhaust particulate matter (PM), such as specific surface area, pore and contact angle, were measured by automatic specific surface area and pore analyser and optical contact angle measuring instrument respectively. The fractal dimension and surface tension of carbon black and PM were calculated. The adsorption capacity of carbon black and PM was compared and analysed, and the relationship between surface characteristic parameters and adsorption capacity of PM was discussed. Via detection and analysis, for carbon and PM, the specific surface area is 78.003 and 65.408m²/g, and average pore size is 13.845 and 14.483nm, and fractal dimension is 2.5885 and 2.5515, and surface tension at 0.985s is 51.1and 56.6mJ/m², respectively. The results show that the specific surface area, pore size distribution, fractal dimension and surface tension of carbon black and diesel exhaust particles are similar. Both carbon black and PM show strong oil affinity and slight hydrophilicity. The PM have a slightly stronger hydrophilicity, a smoother surface and a slightly lower adsorption capacity than carbon black.