Effects of microwave electric field on the structure and association behaviour of asphaltenes: MD and DFT study

•ESP of asphaltene molecules can predict the MD behavior accurately.•Microwave field changes T-shape to π-π stacking, reducing H-bond interaction.•The stacking types of asphaltene molecules highly determines their aggregation.•Suitable microwave significantly inhibits the aggregation of asphaltene molecules.•An optimum microwave power is desirable for viscosity reduction.