Molecular mechanism of hydrophobic tail chain saturation in nonionic surfactants changing the wettability of anthracite

Coal dust is a significant issue when it comes to the safety of coal mine operations. To create efficient surfactants for coal dust, it is crucial to comprehend the molecular principles governing the interactions between surfactants, water, and coal. In this investigation, the macromolecular model of anthracite was constructed. Polysorbate 60 (T60) and Polysorbate 80 (T80) were selected. First, using contact angle measurements, Fourier transform infrared spectroscopy (FTIR) experiment, and Wetting heat measurements, we contrasted how T60 and T80 affected the wettability of coal surfaces. Second, the causes for the various abilities of T60 and T80 were described from a microscopic perspective using molecular dynamics simulation, by evaluating mean square displacement (MSD), mass density, hydrophobic tail chain sequence parameters, interaction energy. According to the findings, T80 has a superior wetting impact on anthracite because it increases the coal surface's polarity and enhances its capacity to bind water molecules; The unsaturated double bond in T80 limited the free expansion of its hydrophobic tail, but following adsorption to the surface of anthracite, it expanded, resulting in a denser and more concentrated layered structure.