Enhancing Multifunctionality: Optimal Properties of Iron-Oxide-Reinforced Polyvinylidene Difluoride Unveiled Through Full Atom Molecular Dynamics Simulations

Nanocomposites made of magnetite (Fe₃O₄) nanoparticles (NP)s with different surface chemistry and polyvinyl difluoride (PVDF) polymer were investigated using full atom molecular dynamics (MD) simulation. NPs with hydroxyl (OH), hexanoic, and oleic acid terminations were considered in this study. The effect of each surface chemistry was investigated in terms of the mechanical properties, the distribution of the internal energy around the NP, and the chain polarization gradient from the interface to the bulk. From this investigation, we find that oleic acid termination, although the most popular, is less favorable for interfacial interaction and local polarization. The OH-terminated NP results in the best configuration for the properties investigated. The hexanoic acid-grafted NP presents a good compromise. Hydrogen bonding governs the induced response of the nanocomposites. Although the hexanoic acid grafted NP presents less hydrogen bonding than the OH-terminated case, the conformation of the hexanoic acid acts as a mobility flow inhibitor, leading to a performance comparable to that of the OH-terminated NP composite. This work led to investigating routes to make nanocomposite materials with optimized properties. These results shed light on the multiple combinations offered by nanocomposites that go beyond the conventional effects of size.