We report for the first time the results from a systematic investigation of how asphaltenes of different polarity affect crystallization and gelation of waxy oils. The more polar asphaltenes were found to be more aromatic in nature and more highly self-aggregated in the solvent. The presence of less polar asphaltenes in the waxy oil reduced the wax appearance temperature and wax precipitation to a greater degree compared to more polar asphaltenes, which was mainly attributed to the difference in the aggregation state of asphaltenes of different polarity. Reducing the polarity of asphaltenes present in the oil also resulted in a lower gelation temperature, lower storage modulus, and lower yield stress, which was probably because the less polar asphaltenes were more similar to wax on the molecular level and, thus, more readily interacting with wax. Notably, a 99% reduction in the yield stress was observed upon the addition of the least polar asphaltenes examined in the present work, in contrast to the 62% yield stress reduction upon the addition of the most polar asphaltenes. This observation may be of industrial significance because it suggests that the crude oil containing less polar asphaltenes may form a softer gel or deposit that is more easily broken or removed. Microscopic analysis showed that the wax crystals precipitated in the presence of less polar asphaltenes have a smaller aspect ratio.

中文翻译：

---

沥青质极性对蜡质油结晶和胶凝的影响

我们首次报告了对不同极性的沥青质如何影响蜡质油的结晶和凝胶化的系统研究结果。发现极性更大的沥青质在本质上更具芳香性，并且在溶剂中具有更高的自聚集性。与极性较大的沥青质相比，蜡质油中极性较小的沥青质的存在降低了蜡的出现温度和蜡沉淀的程度，这主要归因于极性不同的沥青质的聚集状态不同。降低油中存在的沥青质的极性还导致较低的胶凝温度，较低的储能模量和较低的屈服应力，这可能是因为极性较小的沥青质在分子水平上与蜡更相似，因此更易于相互作用用蜡。值得注意的是，在本工作中，添加最小极性的沥青质后，屈服应力降低了99％，而添加极性最大的沥青质后，屈服应力降低了62％。该观察结果可能具有工业意义，因为它表明含极性较小的沥青质的原油可能形成较软的凝胶或沉积物，更易于破碎或除去。显微分析表明，在极性较小的沥青质存在下沉淀的蜡晶体的长径比较小。该观察结果可能具有工业意义，因为它表明含极性较小的沥青质的原油可能形成较软的凝胶或沉积物，更易于破碎或除去。显微分析表明，在极性较小的沥青质存在下沉淀的蜡晶体的长径比较小。该观察结果可能具有工业意义，因为它表明含极性较小的沥青质的原油可能形成较软的凝胶或沉积物，更易于破碎或除去。显微分析表明，在极性较小的沥青质存在下沉淀的蜡晶体的长径比较小。