Fe(II) Spin Crossover/Polymer Hybrid Materials: Investigation of the SCO Behavior via Temperature-Dependent Raman Spectroscopy, Physicochemical Characterization and Migration Release Study.

Zoi G Lada,Georgios N Mathioudakis,Amaia Soto Beobide,George A Voyiatzis

doi:10.3390/molecules26010201

Abstract

Polymeric composites constitute an appealing class of materials with applications in various fields. Spin crossover (SCO) coordination complexes are switchable materials with potential use in data storage and sensors. Their incorporation into polymers can be considered an effective method for their wider practical application. In this study, Fe(II) SCO/polylactic acid hybrid polymeric composites have been prepared by film casting. The mononuclear coordination complex [Fe{N(CN)2}2(abpt)2] was incorporated into polylactic acid. The morphological, structural and thermoanalytical characterization of the composite films were performed via scanning electron microscopy (SEM), attenuated total reflectance (ATR/FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). In addition, the migration release study (MRS) of the SCO compound from the polymeric matrix into the food simulant 50% v/v water/ethanol solution was also examined via UV/Vis absorption. Of particular interest was the investigation of the SCO behavior of the coordination complex after its incorporation into the polymer matrix; it was accomplished by temperature-dependent micro-Raman spectroscopy. The described attempt could be considered a preparatory step toward the development of SCO-based temperature sensors integrated into food packaging materials.

Highlights

IntroductionPolymeric composites are defined as multiphase materials in which the main phase is a synthetic (bio)polymer incorporating biological/inorganic/organic-derived constituents [1]
Polymeric composites are defined as multiphase materials in which the main phase is a syntheticpolymer incorporating biological/inorganic/organic-derived constituents [1].They are considered an appealing class of functional materials with applications in various fields, such as construction, electronic devices, energy applications, aerospace and automotive [2,3,4,5,6]
An absorption band at ~245 nm was presentatafter was present after nine days in the neat. This band remained stable at its maxidays in the neat polylactic acid (PLA) film. This band remained stable at its maximum absorption even after mum the 27 of the total duration of the migration process, in the 27absorption days of theeven total after duration of days the migration process, in line with the stability already line with the stability already shown by the in similar conditions to the present study shown by the PLA in similar conditions to the present study [45]

Summary

Introduction

Polymeric composites are defined as multiphase materials in which the main phase is a synthetic (bio)polymer incorporating biological/inorganic/organic-derived constituents [1]. They are considered an appealing class of functional materials with applications in various fields, such as construction, electronic devices, energy applications, aerospace and automotive [2,3,4,5,6]. Spin crossover (SCO) compounds are mainly six-coordinate first-row transition metal complexes with d4 –d7 configurations. Several studies describe the applications of spin crossover complexes, mainly focused on data storage and sensors [9,10,11,12,13,14]. The exploitation of SCO-based sensors has evolved at an industrial scale in the form of threshold temperature indicators, irreversible overheat indicators of processes, and so on [15]

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Discussion

Conclusion