Polymer Mediated Control and Migration Effects in Spin-Crossover-Polymer Hybrids Towards Tunable Thermal Sensing...

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Polymer Science

Background:

• Controlling spin crossover (SCO) effects in molecular materials is crucial for applications like sensing and memory devices.
• SCO behavior is sensitive to environmental factors, making predictable control challenging.
• Embedding SCO complexes in polymer matrices offers processability but requires understanding matrix-guest interactions.

Purpose of the Study:

• To investigate a polymer-mediated strategy for tuning SCO properties.
• To examine the influence of distinct polymer matrices (PLA, PS, PSF) on a specific Fe(II) SCO complex.
• To quantify the migration behavior of SCO particles within polymer matrices.

Main Methods:

• Incorporation of [Fe(1,10-phenanthroline)2(NCS)2] SCO complex into polylactic acid (PLA), polystyrene (PS), and polysulfone (PSF).
• Characterization using magnetic susceptibility, spectroscopic, and diffraction studies.
• Analysis of SCO particle migration within the polymer matrices.

Main Results:

• Polysulfone (PSF) resulted in lower transition temperatures (T1/2), slower switching kinetics, and enhanced complex retention due to strong matrix confinement.
• Polylactic acid (PLA) and polystyrene (PS) composites showed sharper transitions and higher particle migration, indicating weaker interactions.
• The semi-crystalline nature of PLA extended the hysteresis width, and π-π stacking interactions were observed in PS and PSF matrices.

Conclusions:

• Polymer matrices actively modulate SCO response through varying interactions and confinement effects.
• The choice of polymer significantly impacts SCO properties like transition temperature, kinetics, and hysteresis.
• This work demonstrates a scalable approach for developing functional SCO polymer composites for thermal sensing and responsive devices.