Magnetic-directed fillers migration during micro-injection molding of magnetic polypropylene nanocomposite surfaces with uplifted light trapping microarchitectures for freezing delay and photothermal-enhanced de-icing

•Graphene loaded with Fe3O4 overcome filling resistance to achieve uplifting micropillars under an external magnetic field.•A multi-physical field coupling model for simulating directed migration of fillers with magnetic attraction was proposed.•Injection-molded microarchitectured PP/GP/Fe3O4 parts exhibit great superiority in the photothermal de-icing efficacy.