They are usually defined as substances that are insoluble in n-heptane but soluble in toluene. The undesired aggregation behavior of asphaltenes can form precipitates that may clog pipelines and damage the petroleum industrial facilities, leading to extensive experimental and computational 7-10 studies on the mechanism of asphaltene aggregation. In general, the aggregation of asphaltenes can be described by the modified-Yen model, in which the asphaltene monomer contains one polyaromatic hydrocarbon (PAH) core with average 6-7 fused aromatic rings and aliphatic side chains, which is also called the "island" structure. When their concentration increases, they form nanoaggregates through face-to-face pi-pi stacking between their PAH cores, followed by the nanoaggregate clustering and precipitation from the solution. Based on the modified-Yen model, timely detection of nanoaggregate formation would avoid further damage caused by asphaltene aggregation.