Zhang Dan, Zhang Renyi
Department of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843, USA.
Environ Sci Technol. 2005 Aug 1;39(15):5722-8.
The internal mixing state of soot with sulfuric acid is believed to significantly impact the optical, cloud-forming, and chemical properties of soot-containing aerosols, but little is known about the interaction between soot and sulfuric acid. We report the first measurements of the uptake of H2SO4 on three types of soot generated from methane, hexane, and kerosene combustion. H2SO4 loss on soot is found to be irreversible. The measured uptake coefficients are 0.018 +/- 0.007 for kerosene soot, 0.012 +/- 0.006 for methane soot, and 0.0076 +/- 0.0016 for hexane soot at a total pressure of 1-2 Torr and 298 K assuming a geometric surface area, likely corresponding to the upper limits. Additional experiments using the differential mobility analysis and Fourier transform infrared spectroscopy techniques are carried out to further characterize the interaction of H2SO4 with soot. The results suggest that uptake of H2SO4 takes place efficiently on soot particles, representing an important route to convert hydrophobic soot to hydrophilic aerosols.
人们认为烟灰与硫酸的内部混合状态会显著影响含烟灰气溶胶的光学、成云及化学性质，但对于烟灰与硫酸之间的相互作用却知之甚少。我们首次报告了甲烷、己烷和煤油燃烧产生的三种烟灰对硫酸的吸附测量结果。发现硫酸在烟灰上的损失是不可逆的。在总压力为1 - 2托、温度为298K的条件下，假设几何表面积（可能对应上限），煤油烟灰的测量吸附系数为0.018±0.007，甲烷烟灰为0.012±0.006，己烷烟灰为0.0076±0.0016。使用差分迁移率分析和傅里叶变换红外光谱技术进行了额外实验，以进一步表征硫酸与烟灰的相互作用。结果表明，硫酸能有效地吸附在烟灰颗粒上，这是将疏水性烟灰转化为亲水性气溶胶的一条重要途径。
