Diffusivity of coal and petroleum asphaltene monomers by fluorescence correlation spectroscopy

详细信息    查看全文

• 作者：Rodrigo E. Guerra ; Kosta Ladavac ; A. Ballard Andrews ; Oliver C. Mullins ; Pabitra N. Sen
• 刊名：Fuel
• 出版年：2007
• 出版时间：August 2007
• 年：2007
• 卷：86
• 期：12-13
• 页码：2016-2020
• 全文大小：306 K

文摘

Using fluorescence correlation spectroscopy (FCS) we measure the translational diffusion coefficient of Iino coal asphaltenes and UG8 petroleum asphaltenes dispersed in toluene at extremely low concentrations (0.03–3.0 mg/L). Using a simple scaling argument we compare them with several molecules of known size and molecular weight. We find that Iino coal asphaltene molecules – which have a comparatively small alkane fraction – have a diffusion constant of 1.5 × 10⁻⁵ cm²/s and corresponding hydrodynamic radius close to 0.25 nm: making them significantly smaller than petroleum asphaltenes.