Department of Chemical Engineering, Yale University, New Haven, Connecticut 06510, USA.
Langmuir. 2010 Jun 1;26(11):8021-9. doi: 10.1021/la9049204.
Asphaltenes, among the heaviest components of crude oil, can become unstable under a variety of conditions and precipitate and sediment out of solution. In this report, we present sedimentation measurements for a system of colloidal scale asphaltene particles suspended in heptane. Adding dispersants to the suspension can improve the stability of the system and can mediate the transition from a power-law collapse in the sedimentation front to a rising front. Additional dispersant beyond a crossover concentration can cause a significant delay in the dynamics. Dynamic light scattering measurements suggest that the stabilization provided by the dispersants may occur through a reduction of both the size and polydispersity of the asphaltene particles in suspension.
沥青质是原油中最重的成分之一，在各种条件下都可能变得不稳定，并从溶液中沉淀和沉降出来。在本报告中，我们介绍了胶体尺度沥青质颗粒在庚烷中悬浮体系的沉降测量结果。向悬浮液中添加分散剂可以改善体系的稳定性，并可以介导沉降前沿从幂律崩溃到上升前沿的转变。超过交叉浓度的额外分散剂会导致动力学显著延迟。动态光散射测量表明，分散剂提供的稳定性可能是通过减少悬浮液中沥青质颗粒的大小和多分散性来实现的。
