In Situ Study of FePt Nanoparticles‐Induced Morphology Development during Printing of Magnetic Hybrid Diblock Copolymer Films

• Published in: Advanced functional materials 2022-01, Vol.32 (4), p.2107667-n/a
• Main Authors: Cao, Wei, Yin, Shanshan, Bitsch, Martin, Liang, Suzhe, Plank, Martina, Opel, Matthias, Scheel, Manuel A., Gallei, Markus, Janka, Oliver, Schwartzkopf, Matthias, Roth, Stephan V., Müller‐Buschbaum, Peter
• Format: Article
• Language: English
• Subjects: Binary alloys; Block copolymers; Diblock co-polymer films; Diblock-copolymer; Esters; FePt nanoparticles; Film formations; Functional materials; Grazing incidence small-angle X-ray scattering; Hybrid film; Hybrid materials; In situ grazing-incidence small-angle X-ray scattering; Intermetallic compounds; Iron alloys; Iron compounds; magnetic nanoparticles; Magnetic properties; Materials science; Metastable state; Morphology; Nanomagnetics; Nanoparticles; Platinum alloys; Platinum compounds; Polymethyl methacrylate; Polystyrene resins; Printing; Solvents; Superparamagnetic behavior; Temperature dependence; Ultra-high-molecular-weight; Ultrahigh molecular weight; ultrahigh molecular weight, diblock copolymers; X ray scattering
• ISSN: 1616-301X; 1616-3028; 1616-3028
• DOI: 10.1002/adfm.202107667

The development of magnetic hybrid films containing diblock copolymers (DBCs) and magnetic nanoparticles (NPs) by printing is a highly promising method for scalable and low‐cost fabrication. During printing, the drying and arrangement kinetics of the DBC and magnetic NPs play an important role in the film formation concerning morphology and magnetic properties. In this study, the morphology evolution of ultrahigh molecular weight DBC polystyrene‐block‐poly(methyl methacrylate) and magnetic iron platinum (FePt) NPs is investigated with grazing‐incidence small‐angle X‐ray scattering (GISAXS) in situ during printing. For comparison, a pure DBC film is printed without FePt NPs under the same conditions. The GISAXS data suggest that the addition of NPs accelerates the solvent evaporation, leading to a faster film formation of the hybrid film compared to the pure film. As the solvent is almost evaporated, a metastable state is observed in both films. Compared with the pure film, such a metastable state continues longer during the printing process of the hybrid film because of the presence of FePt NPs, which inhibits the reorganization of the DBC chains. Moreover, investigations of the field‐dependent magnetization and temperature‐dependent susceptibility indicate that the printed hybrid film is superparamagnetic, which makes this film class promising for magnetic sensors. The influence of FePt nanoparticles (NPs) on the film formation of hybrid diblock copolymer films is investigated with in situ grazing‐incidence small‐angle X‐ray scattering during printing. The two characteristic morphology development processes, domain shrinkage, and duration of a metastable state are altered by the FePt NPs, resulting in a different final film morphology compared with a pure diblock copolymer film.