Strain-Mediated PVA-MIP-NiO Coupling for Molecularly Selective Magnetic Response

Molecularly imprinted polymers (MIPs) provide exceptional chemical selectivity; however, existing MIP-based sensors primarily rely on electrical, optical, or electrochemical transduction mechanisms. Here, we introduce a hybrid materials concept based on the integration of a poly(vinyl alcohol) (PVA)-based MIP designed for methanol recognition with antiferromagnetic (AFM) nickel oxide (NiO), providing a mechanism through which molecular recognition can influence magnetic properties through mechanically mediated coupling. Using molecular dynamics (MD) and density functional theory (DFT) simulations, we show that nanoscale strain generated within the MIP upon methanol uptake can modify the electronic structure and magnetocrystalline anisotropy energy (MAE) of AFM NiO. At approximately 70% methanol occupancy, the simulated MIP generates approximately 4% tensile strain, which under ideal strain transfer drives the calculated NiO MAE toward zero. Atomistic characterization of the PVA/NiO interface combined with finite-length shear-lag modeling further quantifies the strain-transfer efficiency and its dependence on layer geometry. For the geometries considered, calculated transfer efficiencies reach approximately 33%, while comparison with the DFT-derived interfacial shear strength defines the strain-transfer limit before interfacial sliding. Within this constraint, the transferred strain remains sufficient to produce appreciable modifications of the NiO MAE. These results demonstrate that molecular-to-magnetic coupling is governed not only by the strain generated during molecular recognition but also by interfacial mechanics and heterostructure geometry. The resulting MD-DFT-interface framework provides a quantitative approach for connecting molecular recognition, interfacial strain transfer, and magnetic response in MIP-AFM heterostructures, establishing a basis for future experimental investigation of molecularly induced modulation of collective magnetic properties.