Study on the performance of ATP grafting basalt fiber based on the plant root bionic idea and its adsorption characteristics with asphalt

Nano-attapulgite (ATP) is a layered silicate mineral with abundant reserves, large specific surface area, and low cost. The unique structure of ATP has attracted wide attention in the field of adsorption. In this study, a preparation technology of ATP grafting basalt fiber (BF) was proposed by chemical grafting method based on the idea of plant root bionics. The optimal preparation process of ATP grafting BF was determined through the tests of asphalt absorption performance, thermal stability performance, and segregation dispersion performance. The mechanism of ATP grafting BF was analyzed by micro-morphology, functional group changes, and elemental composition. Finally, the adsorption performance of ATP grafting BF was investigated on the basis of adsorption kinetics model and molecular dynamics simulation. The study results indicated that ATP-BF_HCl had better compatibility and wettability with asphalt. The quasi-second-order kinetic equation could better fit the adsorption process of ATP-BF_HCl on asphaltene, which indicated that ATP-BF_HCl adsorbed asphaltene with chemisorption or ion exchange. The diffusion coefficient and diffusion activation energy of the saturate and the aromatic were larger, indicating a smaller molecular weight and faster movement, and lightweight components of asphalt are more easily adsorbed on the surface of ATP. The diffusion activation energy of asphaltene is the smallest and the reaction is the easiest to take place, which indicates that it is the first to react during temperature increase. The research results can provide a theoretical basis and technical support for BF surface treatment technology.