Study on the microcosmic superlubricity mechanism of PVPA affected by metal cations

Abstract Hydrophilic polymer coatings on artificial implants generate excellent tribological properties. The friction properties of are affected by salt ion factors. Herein, the atomic force microscopy (AFM) was used to show that superlubricity achieved between poly(vinylphosphonic acid) (PVPA)-modified Ti6Al4V and polystyrene (PS) microsphere probe lubricated with monovalent solutions (LiCl, NaCl, KCl, CsCl). Considering adhesion is an important cause changes, AFM further utilized obtain pairs in different solutions. results indicated larger cation radius lubricant, smaller adhesion, lower coefficient PVPA coating. electrostatic interaction one-valence cations lubricants analyzed molecular dynamics (MD) simulation as it found be main influencing factor adhesion. Combined analysis adjusting size tribo-pairs can changed, eventually magnitude affected. This study opens up a new avenue for analyzing characteristics hydrophilic from perspective intermolecular forces.