A directional entrapment modification on the polyethylene surface by the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether

•A novel entrapment method for surface modification of HDPE by the amphiphilic AEO modifier is proposed.•Hydrophobicity of AEO was favorable to the entrapment modification.•A larger and hydrophobic micelle of AEO was favorable to the entrapment modification.•A directional entrapment mechanism is suggested.•This directional entrapment method reached larger modifier coverage than that by the traditional entrapment method.