Rejek T, Schweizer P, Joch D, Portilla L, Spiecker E, Halik M (2020)
Publication Type: Journal article
Publication year: 2020
Book Volume: 53
Pages Range: 5604-5613
Journal Issue: 13
DOI: 10.1021/acs.macromol.9b02760
The interplay between microphase separation and crystallization in the semicrystalline PS-b-PEO system is investigated in the context of solution-based thin film formation. For this end, the film morphology is studied depending on the PEO volume fraction in a broad f(vol)(PEO) range from 0.17 to 0.8. Topographical two-dimensional AFM measurements are extended to the third dimension to gain information about the vertical film structure by successive removal of the surface layer by controlled O-2 plasma etching. The depth profiling reveals a dynamic film formation process where competing microphase separation and crystallization forces create a two-layered BCP film composed of a buried microphase-separated layer featuring cylinder morphology under a fine-structured crystalline lamellae surface layer. An explanation is presented considering the thermal properties and solvent interactions. Phase-selective TiO2 nanoparticles addressing the PEO block are further used to demonstrate the accessibility of the buried microphase-separated layer and thus that we were able to extend the usable range of the phase diagram of PS-b-PEO thin films to the PEO-rich regime. Lastly, the impact of a second film-air interface is shown, which is formed in free-standing BCP membranes.
APA:
Rejek, T., Schweizer, P., Joch, D., Portilla, L., Spiecker, E., & Halik, M. (2020). Buried Microphase Separation by Dynamic Interplay of Crystallization and Microphase Separation in Semicrystalline PEO-Rich PS-b-PEO Block Copolymer Thin Films. Macromolecules, 53(13), 5604-5613. https://doi.org/10.1021/acs.macromol.9b02760
MLA:
Rejek, Tobias, et al. "Buried Microphase Separation by Dynamic Interplay of Crystallization and Microphase Separation in Semicrystalline PEO-Rich PS-b-PEO Block Copolymer Thin Films." Macromolecules 53.13 (2020): 5604-5613.
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