Confined Crystallization of Spin‐Crossover Nanoparticles in Block‐Copolymer Micelles. Issue 14 (3rd February 2020)

• Record Type: Journal Article
• Authors: Göbel, Christoph; Hils, Christian; Drechsler, Markus; Baabe, Dirk; Greiner, Andreas; Schmalz, Holger; Weber, Birgit
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 14(2020)
• Page Start: 5765
• Page End: 5770
• Publication Date: 2020-02-03
• Subjects: block copolymers -- composite materials -- electrospinning -- nanoparticles -- spin crossover; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201914343
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Nanoparticles of the spin‐crossover coordination polymer [FeL(bipy)] n were synthesized by confined crystallization within the core of polystyrene‐ block ‐poly(4‐vinylpyridine) (PS‐ b ‐P4VP) diblock copolymer micelles. The 4VP units in the micellar core act as coordination sites for the Fe complex. In the bulk material, the spin‐crossover nanoparticles in the core are well isolated from each other allowing thermal treatment without disintegration of their structure. During annealing above the glass transition temperature of the PS block, the transition temperature is shifted gradually to higher temperatures from the as‐synthesized product ( T 1/2 ↓=163 K and T 1/2 ↑=170 K) to the annealed product ( T 1/2 ↓=203 K and T 1/2 ↑=217 K) along with an increase in hysteresis width from 6 K to 14 K. Thus, the spin‐crossover properties can be shifted towards the properties of the related bulk material. The stability of the nanocomposite allows further processing, such as electrospinning from solution. Abstract : Spin doctor : The synthesis and characterization of spin‐crossover nanoparticles with improved spin‐crossover properties in a block‐copolymer matrix gives a spin‐crossover nanocomposite which is stable enough to allow further processing, such as electrospinning from solution.