Table 1.
Industrial element analysis of bituminous coal.
Fig 1.
Experimental solution preparation.
Fig 2.
Construction of the bituminous coal molecular model.
Table 2.
Surfactant molecular ratio and label in molecular dynamics simulation.
Fig 3.
Construction of water/compound surfactant/bituminous coal model system.
Fig 4.
Surface tension of surfactant solutions at different concentrations.
Table 3.
Surface activity parameters of surfactant solutions.
Table 4.
Surfactant compounding combination and surface tension.
Table 5.
Dynamic wetting parameters of solution.
Fig 5.
Dynamic contact angle change.
Fig 6.
Adhesion work, spreading work and wetting work of the composite solution.
Fig 7.
Surface electrostatic potential distribution of water and bituminous coal.
Fig 8.
Surface electrostatic potential distribution of surfactant molecules.
Table 6.
Interaction energy of single surfactant/water/coal system.
Table 7.
Interaction energy of composite surfactant/water/coal system.
Fig 9.
Radial distribution function of hydrophilic groups and water.
Fig 10.
MSD curves of each system.
Fig 11.
The self-diffusion coefficient D of each system.
Table 8.
The content of C, O and other elements on the surface of coal samples.
Fig 12.
XPS spectra of coal samples before and after surfactant treatment.
Fig 13.
Results of the split peak fitting of C1s for coal samples.
Fig 14.
Results of the split peak fitting of O1s for coal samples.
Fig 15.
Surface morphology of bituminous coal after treatment.